HTTP route components

HTTP route components

Routing architecture overview
HTTP router filter

config.route.v3.VirtualHost

The top level element in the routing configuration is a virtual host. Each virtual host has a logical name as well as a set of domains that get routed to it based on the incoming request’s host header. This allows a single listener to service multiple top level domain path trees. Once a virtual host is selected based on the domain, the routes are processed in order to see which upstream cluster to route to or whether to perform a redirect.

{
  "name": "...",
  "domains": [],
  "routes": [],
  "require_tls": "...",
  "virtual_clusters": [],
  "rate_limits": [],
  "request_headers_to_add": [],
  "request_headers_to_remove": [],
  "response_headers_to_add": [],
  "response_headers_to_remove": [],
  "cors": "{...}",
  "typed_per_filter_config": "{...}",
  "include_request_attempt_count": "...",
  "include_attempt_count_in_response": "...",
  "retry_policy": "{...}",
  "hedge_policy": "{...}",
  "per_request_buffer_limit_bytes": "{...}"
}

name

(string, REQUIRED) The logical name of the virtual host. This is used when emitting certain statistics but is not relevant for routing.

domains

(string, REQUIRED) A list of domains (host/authority header) that will be matched to this virtual host. Wildcard hosts are supported in the suffix or prefix form.

Domain search order:
1. Exact domain names: www.foo.com.
2. Suffix domain wildcards: *.foo.com or *-bar.foo.com.
3. Prefix domain wildcards: foo.* or foo-*.
4. Special wildcard * matching any domain.

Note

The wildcard will not match the empty string. e.g. *-bar.foo.com will match baz-bar.foo.com but not -bar.foo.com. The longest wildcards match first. Only a single virtual host in the entire route configuration can match on *. A domain must be unique across all virtual hosts or the config will fail to load.

Domains cannot contain control characters. This is validated by the well_known_regex HTTP_HEADER_VALUE.

routes

(config.route.v3.Route) The list of routes that will be matched, in order, for incoming requests. The first route that matches will be used.

require_tls

(config.route.v3.VirtualHost.TlsRequirementType) Specifies the type of TLS enforcement the virtual host expects. If this option is not specified, there is no TLS requirement for the virtual host.

virtual_clusters

(config.route.v3.VirtualCluster) A list of virtual clusters defined for this virtual host. Virtual clusters are used for additional statistics gathering.

rate_limits

(config.route.v3.RateLimit) Specifies a set of rate limit configurations that will be applied to the virtual host.

request_headers_to_add

(config.core.v3.HeaderValueOption) Specifies a list of HTTP headers that should be added to each request handled by this virtual host. Headers specified at this level are applied after headers from enclosed config.route.v3.Route and before headers from the enclosing config.route.v3.RouteConfiguration. For more information, including details on header value syntax, see the documentation on custom request headers.

request_headers_to_remove

(string) Specifies a list of HTTP headers that should be removed from each request handled by this virtual host.

response_headers_to_add

(config.core.v3.HeaderValueOption) Specifies a list of HTTP headers that should be added to each response handled by this virtual host. Headers specified at this level are applied after headers from enclosed config.route.v3.Route and before headers from the enclosing config.route.v3.RouteConfiguration. For more information, including details on header value syntax, see the documentation on custom request headers.

response_headers_to_remove

(string) Specifies a list of HTTP headers that should be removed from each response handled by this virtual host.

cors

(config.route.v3.CorsPolicy) Indicates that the virtual host has a CORS policy.

typed_per_filter_config

(map<string, Any>) The per_filter_config field can be used to provide virtual host-specific configurations for filters. The key should match the filter name, such as envoy.filters.http.buffer for the HTTP buffer filter. Use of this field is filter specific; see the HTTP filter documentation for if and how it is utilized.

include_request_attempt_count

(bool) Decides whether the x-envoy-attempt-count header should be included in the upstream request. Setting this option will cause it to override any existing header value, so in the case of two Envoys on the request path with this option enabled, the upstream will see the attempt count as perceived by the second Envoy. Defaults to false. This header is unaffected by the suppress_envoy_headers flag.

include_attempt_count_in_response

(bool) Decides whether the x-envoy-attempt-count header should be included in the downstream response. Setting this option will cause the router to override any existing header value, so in the case of two Envoys on the request path with this option enabled, the downstream will see the attempt count as perceived by the Envoy closest upstream from itself. Defaults to false. This header is unaffected by the suppress_envoy_headers flag.

retry_policy

(config.route.v3.RetryPolicy) Indicates the retry policy for all routes in this virtual host. Note that setting a route level entry will take precedence over this config and it’ll be treated independently (e.g.: values are not inherited).

hedge_policy

(config.route.v3.HedgePolicy) Indicates the hedge policy for all routes in this virtual host. Note that setting a route level entry will take precedence over this config and it’ll be treated independently (e.g.: values are not inherited).

per_request_buffer_limit_bytes

(UInt32Value) The maximum bytes which will be buffered for retries and shadowing. If set and a route-specific limit is not set, the bytes actually buffered will be the minimum value of this and the listener per_connection_buffer_limit_bytes.

Enum config.route.v3.VirtualHost.TlsRequirementType

[config.route.v3.VirtualHost.TlsRequirementType proto]

NONE

(DEFAULT) ⁣No TLS requirement for the virtual host.

EXTERNAL_ONLY

⁣External requests must use TLS. If a request is external and it is not using TLS, a 301 redirect will be sent telling the client to use HTTPS.

ALL

⁣All requests must use TLS. If a request is not using TLS, a 301 redirect will be sent telling the client to use HTTPS.

config.route.v3.FilterAction

[config.route.v3.FilterAction proto]

A filter-defined action type.

{
  "action": "{...}"
}

action

(Any)

config.route.v3.Route

[config.route.v3.Route proto]

A route is both a specification of how to match a request as well as an indication of what to do next (e.g., redirect, forward, rewrite, etc.).

Attention

Envoy supports routing on HTTP method via header matching.

{
  "name": "...",
  "match": "{...}",
  "route": "{...}",
  "redirect": "{...}",
  "direct_response": "{...}",
  "metadata": "{...}",
  "decorator": "{...}",
  "typed_per_filter_config": "{...}",
  "request_headers_to_add": [],
  "request_headers_to_remove": [],
  "response_headers_to_add": [],
  "response_headers_to_remove": [],
  "tracing": "{...}",
  "per_request_buffer_limit_bytes": "{...}"
}

name

(string) Name for the route.

match

(config.route.v3.RouteMatch, REQUIRED) Route matching parameters.

route

(config.route.v3.RouteAction) Route request to some upstream cluster.

Precisely one of route, redirect, direct_response must be set.

redirect

(config.route.v3.RedirectAction) Return a redirect.

Precisely one of route, redirect, direct_response must be set.

direct_response

(config.route.v3.DirectResponseAction) Return an arbitrary HTTP response directly, without proxying.

Precisely one of route, redirect, direct_response must be set.

metadata

(config.core.v3.Metadata) The Metadata field can be used to provide additional information about the route. It can be used for configuration, stats, and logging. The metadata should go under the filter namespace that will need it. For instance, if the metadata is intended for the Router filter, the filter name should be specified as envoy.filters.http.router.

decorator

(config.route.v3.Decorator) Decorator for the matched route.

typed_per_filter_config

(map<string, Any>) The typed_per_filter_config field can be used to provide route-specific configurations for filters. The key should match the filter name, such as envoy.filters.http.buffer for the HTTP buffer filter. Use of this field is filter specific; see the HTTP filter documentation for if and how it is utilized.

request_headers_to_add

(config.core.v3.HeaderValueOption) Specifies a set of headers that will be added to requests matching this route. Headers specified at this level are applied before headers from the enclosing config.route.v3.VirtualHost and config.route.v3.RouteConfiguration. For more information, including details on header value syntax, see the documentation on custom request headers.

request_headers_to_remove

(string) Specifies a list of HTTP headers that should be removed from each request matching this route.

response_headers_to_add

(config.core.v3.HeaderValueOption) Specifies a set of headers that will be added to responses to requests matching this route. Headers specified at this level are applied before headers from the enclosing config.route.v3.VirtualHost and config.route.v3.RouteConfiguration. For more information, including details on header value syntax, see the documentation on custom request headers.

response_headers_to_remove

(string) Specifies a list of HTTP headers that should be removed from each response to requests matching this route.

tracing

(config.route.v3.Tracing) Presence of the object defines whether the connection manager’s tracing configuration is overridden by this route specific instance.

per_request_buffer_limit_bytes

(UInt32Value) The maximum bytes which will be buffered for retries and shadowing. If set, the bytes actually buffered will be the minimum value of this and the listener per_connection_buffer_limit_bytes.

config.route.v3.WeightedCluster

[config.route.v3.WeightedCluster proto]

Compared to the cluster field that specifies a single upstream cluster as the target of a request, the weighted_clusters option allows for specification of multiple upstream clusters along with weights that indicate the percentage of traffic to be forwarded to each cluster. The router selects an upstream cluster based on the weights.

{
  "clusters": [],
  "total_weight": "{...}",
  "runtime_key_prefix": "..."
}

clusters

(config.route.v3.WeightedCluster.ClusterWeight, REQUIRED) Specifies one or more upstream clusters associated with the route.

total_weight

(UInt32Value) Specifies the total weight across all clusters. The sum of all cluster weights must equal this value, which must be greater than 0. Defaults to 100.

runtime_key_prefix

(string) Specifies the runtime key prefix that should be used to construct the runtime keys associated with each cluster. When the runtime_key_prefix is specified, the router will look for weights associated with each upstream cluster under the key runtime_key_prefix + “.” + cluster[i].name where cluster[i] denotes an entry in the clusters array field. If the runtime key for the cluster does not exist, the value specified in the configuration file will be used as the default weight. See the runtime documentation for how key names map to the underlying implementation.

config.route.v3.WeightedCluster.ClusterWeight

[config.route.v3.WeightedCluster.ClusterWeight proto]

{
  "name": "...",
  "weight": "{...}",
  "metadata_match": "{...}",
  "request_headers_to_add": [],
  "request_headers_to_remove": [],
  "response_headers_to_add": [],
  "response_headers_to_remove": [],
  "typed_per_filter_config": "{...}"
}

name

(string, REQUIRED) Name of the upstream cluster. The cluster must exist in the cluster manager configuration.

weight

(UInt32Value) An integer between 0 and total_weight. When a request matches the route, the choice of an upstream cluster is determined by its weight. The sum of weights across all entries in the clusters array must add up to the total_weight, which defaults to 100.

metadata_match

(config.core.v3.Metadata) Optional endpoint metadata match criteria used by the subset load balancer. Only endpoints in the upstream cluster with metadata matching what is set in this field will be considered for load balancing. Note that this will be merged with what’s provided in RouteAction.metadata_match, with values here taking precedence. The filter name should be specified as envoy.lb.

request_headers_to_add

(config.core.v3.HeaderValueOption) Specifies a list of headers to be added to requests when this cluster is selected through the enclosing config.route.v3.RouteAction. Headers specified at this level are applied before headers from the enclosing config.route.v3.Route, config.route.v3.VirtualHost, and config.route.v3.RouteConfiguration. For more information, including details on header value syntax, see the documentation on custom request headers.

request_headers_to_remove

(string) Specifies a list of HTTP headers that should be removed from each request when this cluster is selected through the enclosing config.route.v3.RouteAction.

response_headers_to_add

(config.core.v3.HeaderValueOption) Specifies a list of headers to be added to responses when this cluster is selected through the enclosing config.route.v3.RouteAction. Headers specified at this level are applied before headers from the enclosing config.route.v3.Route, config.route.v3.VirtualHost, and config.route.v3.RouteConfiguration. For more information, including details on header value syntax, see the documentation on custom request headers.

response_headers_to_remove

(string) Specifies a list of headers to be removed from responses when this cluster is selected through the enclosing config.route.v3.RouteAction.

typed_per_filter_config

(map<string, Any>) The per_filter_config field can be used to provide weighted cluster-specific configurations for filters. The key should match the filter name, such as envoy.filters.http.buffer for the HTTP buffer filter. Use of this field is filter specific; see the HTTP filter documentation for if and how it is utilized.

config.route.v3.RouteMatch

[config.route.v3.RouteMatch proto]

{
  "prefix": "...",
  "path": "...",
  "safe_regex": "{...}",
  "case_sensitive": "{...}",
  "runtime_fraction": "{...}",
  "headers": [],
  "query_parameters": [],
  "grpc": "{...}",
  "tls_context": "{...}"
}

prefix

(string) If specified, the route is a prefix rule meaning that the prefix must match the beginning of the :path header.

Precisely one of prefix, path, safe_regex must be set.

path

(string) If specified, the route is an exact path rule meaning that the path must exactly match the :path header once the query string is removed.

Precisely one of prefix, path, safe_regex must be set.

safe_regex

(type.matcher.v3.RegexMatcher) If specified, the route is a regular expression rule meaning that the regex must match the :path header once the query string is removed. The entire path (without the query string) must match the regex. The rule will not match if only a subsequence of the :path header matches the regex.

Precisely one of prefix, path, safe_regex must be set.

case_sensitive

(BoolValue) Indicates that prefix/path matching should be case insensitive. The default is true.

runtime_fraction

(config.core.v3.RuntimeFractionalPercent) Indicates that the route should additionally match on a runtime key. Every time the route is considered for a match, it must also fall under the percentage of matches indicated by this field. For some fraction N/D, a random number in the range [0,D) is selected. If the number is <= the value of the numerator N, or if the key is not present, the default value, the router continues to evaluate the remaining match criteria. A runtime_fraction route configuration can be used to roll out route changes in a gradual manner without full code/config deploys. Refer to the traffic shifting docs for additional documentation.

Note

Parsing this field is implemented such that the runtime key’s data may be represented as a FractionalPercent proto represented as JSON/YAML and may also be represented as an integer with the assumption that the value is an integral percentage out of 100. For instance, a runtime key lookup returning the value “42” would parse as a FractionalPercent whose numerator is 42 and denominator is HUNDRED. This preserves legacy semantics.

headers

(config.route.v3.HeaderMatcher) Specifies a set of headers that the route should match on. The router will check the request’s headers against all the specified headers in the route config. A match will happen if all the headers in the route are present in the request with the same values (or based on presence if the value field is not in the config).

query_parameters

(config.route.v3.QueryParameterMatcher) Specifies a set of URL query parameters on which the route should match. The router will check the query string from the path header against all the specified query parameters. If the number of specified query parameters is nonzero, they all must match the path header’s query string for a match to occur.

grpc

(config.route.v3.RouteMatch.GrpcRouteMatchOptions) If specified, only gRPC requests will be matched. The router will check that the content-type header has a application/grpc or one of the various application/grpc+ values.

tls_context

(config.route.v3.RouteMatch.TlsContextMatchOptions) If specified, the client tls context will be matched against the defined match options.

config.route.v3.RouteMatch.GrpcRouteMatchOptions

[config.route.v3.RouteMatch.GrpcRouteMatchOptions proto]

{}

config.route.v3.RouteMatch.TlsContextMatchOptions

[config.route.v3.RouteMatch.TlsContextMatchOptions proto]

{
  "presented": "{...}",
  "validated": "{...}"
}

presented

(BoolValue) If specified, the route will match against whether or not a certificate is presented. If not specified, certificate presentation status (true or false) will not be considered when route matching.

validated

(BoolValue) If specified, the route will match against whether or not a certificate is validated. If not specified, certificate validation status (true or false) will not be considered when route matching.

config.route.v3.CorsPolicy

[config.route.v3.CorsPolicy proto]

{
  "allow_origin_string_match": [],
  "allow_methods": "...",
  "allow_headers": "...",
  "expose_headers": "...",
  "max_age": "...",
  "allow_credentials": "{...}",
  "filter_enabled": "{...}",
  "shadow_enabled": "{...}"
}

allow_origin_string_match

(type.matcher.v3.StringMatcher) Specifies string patterns that match allowed origins. An origin is allowed if any of the string matchers match.

allow_methods

(string) Specifies the content for the access-control-allow-methods header.

allow_headers

(string) Specifies the content for the access-control-allow-headers header.

expose_headers

(string) Specifies the content for the access-control-expose-headers header.

max_age

(string) Specifies the content for the access-control-max-age header.

allow_credentials

(BoolValue) Specifies whether the resource allows credentials.

filter_enabled

(config.core.v3.RuntimeFractionalPercent) Specifies the % of requests for which the CORS filter is enabled.

If neither enabled, filter_enabled, nor shadow_enabled are specified, the CORS filter will be enabled for 100% of the requests.

If runtime_key is specified, Envoy will lookup the runtime key to get the percentage of requests to filter.

shadow_enabled

(config.core.v3.RuntimeFractionalPercent) Specifies the % of requests for which the CORS policies will be evaluated and tracked, but not enforced.

This field is intended to be used when filter_enabled and enabled are off. One of those fields have to explicitly disable the filter in order for this setting to take effect.

If runtime_key is specified, Envoy will lookup the runtime key to get the percentage of requests for which it will evaluate and track the request’s Origin to determine if it’s valid but will not enforce any policies.

config.route.v3.RouteAction

[config.route.v3.RouteAction proto]

{
  "cluster": "...",
  "cluster_header": "...",
  "weighted_clusters": "{...}",
  "cluster_not_found_response_code": "...",
  "metadata_match": "{...}",
  "prefix_rewrite": "...",
  "regex_rewrite": "{...}",
  "host_rewrite_literal": "...",
  "auto_host_rewrite": "{...}",
  "host_rewrite_header": "...",
  "timeout": "{...}",
  "idle_timeout": "{...}",
  "retry_policy": "{...}",
  "request_mirror_policies": [],
  "priority": "...",
  "rate_limits": [],
  "include_vh_rate_limits": "{...}",
  "hash_policy": [],
  "cors": "{...}",
  "max_grpc_timeout": "{...}",
  "grpc_timeout_offset": "{...}",
  "upgrade_configs": [],
  "internal_redirect_action": "...",
  "max_internal_redirects": "{...}",
  "hedge_policy": "{...}"
}

cluster

(string) Indicates the upstream cluster to which the request should be routed to.

Precisely one of cluster, cluster_header, weighted_clusters must be set.

cluster_header

(string) Envoy will determine the cluster to route to by reading the value of the HTTP header named by cluster_header from the request headers. If the header is not found or the referenced cluster does not exist, Envoy will return a 404 response.

Attention

Internally, Envoy always uses the HTTP/2 :authority header to represent the HTTP/1 Host header. Thus, if attempting to match on Host, match on :authority instead.

Precisely one of cluster, cluster_header, weighted_clusters must be set.

weighted_clusters

(config.route.v3.WeightedCluster) Multiple upstream clusters can be specified for a given route. The request is routed to one of the upstream clusters based on weights assigned to each cluster. See traffic splitting for additional documentation.

Precisely one of cluster, cluster_header, weighted_clusters must be set.

cluster_not_found_response_code

(config.route.v3.RouteAction.ClusterNotFoundResponseCode) The HTTP status code to use when configured cluster is not found. The default response code is 503 Service Unavailable.

metadata_match

(config.core.v3.Metadata) Optional endpoint metadata match criteria used by the subset load balancer. Only endpoints in the upstream cluster with metadata matching what’s set in this field will be considered for load balancing. If using weighted_clusters, metadata will be merged, with values provided there taking precedence. The filter name should be specified as envoy.lb.

prefix_rewrite

(string) Indicates that during forwarding, the matched prefix (or path) should be swapped with this value. This option allows application URLs to be rooted at a different path from those exposed at the reverse proxy layer. The router filter will place the original path before rewrite into the x-envoy-original-path header.

Only one of prefix_rewrite or regex_rewrite may be specified.

Attention

Pay careful attention to the use of trailing slashes in the route’s match prefix value. Stripping a prefix from a path requires multiple Routes to handle all cases. For example, rewriting /prefix to / and /prefix/etc to /etc cannot be done in a single Route, as shown by the below config entries:

- match:
    prefix: "/prefix/"
  route:
    prefix_rewrite: "/"
- match:
    prefix: "/prefix"
  route:
    prefix_rewrite: "/"

Having above entries in the config, requests to /prefix will be stripped to /, while requests to /prefix/etc will be stripped to /etc.

regex_rewrite

(type.matcher.v3.RegexMatchAndSubstitute) Indicates that during forwarding, portions of the path that match the pattern should be rewritten, even allowing the substitution of capture groups from the pattern into the new path as specified by the rewrite substitution string. This is useful to allow application paths to be rewritten in a way that is aware of segments with variable content like identifiers. The router filter will place the original path as it was before the rewrite into the x-envoy-original-path header.

Only one of prefix_rewrite or regex_rewrite may be specified.

Examples using Google’s RE2 engine:

The path pattern ^/service/([^/]+)(/.*)$ paired with a substitution string of \2/instance/\1 would transform /service/foo/v1/api into /v1/api/instance/foo.
The pattern one paired with a substitution string of two would transform /xxx/one/yyy/one/zzz into /xxx/two/yyy/two/zzz.
The pattern ^(.*?)one(.*)$ paired with a substitution string of \1two\2 would replace only the first occurrence of one, transforming path /xxx/one/yyy/one/zzz into /xxx/two/yyy/one/zzz.
The pattern (?i)/xxx/ paired with a substitution string of /yyy/ would do a case-insensitive match and transform path /aaa/XxX/bbb to /aaa/yyy/bbb.

host_rewrite_literal

(string) Indicates that during forwarding, the host header will be swapped with this value.

Only one of host_rewrite_literal, auto_host_rewrite, host_rewrite_header may be set.

auto_host_rewrite

(BoolValue) Indicates that during forwarding, the host header will be swapped with the hostname of the upstream host chosen by the cluster manager. This option is applicable only when the destination cluster for a route is of type strict_dns or logical_dns. Setting this to true with other cluster types has no effect.

Only one of host_rewrite_literal, auto_host_rewrite, host_rewrite_header may be set.

host_rewrite_header

(string) Indicates that during forwarding, the host header will be swapped with the content of given downstream or custom header. If header value is empty, host header is left intact.

Attention

Pay attention to the potential security implications of using this option. Provided header must come from trusted source.

Only one of host_rewrite_literal, auto_host_rewrite, host_rewrite_header may be set.

timeout

(Duration) Specifies the upstream timeout for the route. If not specified, the default is 15s. This spans between the point at which the entire downstream request (i.e. end-of-stream) has been processed and when the upstream response has been completely processed. A value of 0 will disable the route’s timeout.

Note

This timeout includes all retries. See also x-envoy-upstream-rq-timeout-ms, x-envoy-upstream-rq-per-try-timeout-ms, and the retry overview.

idle_timeout

(Duration) Specifies the idle timeout for the route. If not specified, there is no per-route idle timeout, although the connection manager wide stream_idle_timeout will still apply. A value of 0 will completely disable the route’s idle timeout, even if a connection manager stream idle timeout is configured.

The idle timeout is distinct to timeout, which provides an upper bound on the upstream response time; idle_timeout instead bounds the amount of time the request’s stream may be idle.

After header decoding, the idle timeout will apply on downstream and upstream request events. Each time an encode/decode event for headers or data is processed for the stream, the timer will be reset. If the timeout fires, the stream is terminated with a 408 Request Timeout error code if no upstream response header has been received, otherwise a stream reset occurs.

retry_policy

(config.route.v3.RetryPolicy) Indicates that the route has a retry policy. Note that if this is set, it’ll take precedence over the virtual host level retry policy entirely (e.g.: policies are not merged, most internal one becomes the enforced policy).

request_mirror_policies

(config.route.v3.RouteAction.RequestMirrorPolicy) Indicates that the route has request mirroring policies.

priority

(config.core.v3.RoutingPriority) Optionally specifies the routing priority.

rate_limits

(config.route.v3.RateLimit) Specifies a set of rate limit configurations that could be applied to the route.

include_vh_rate_limits

(BoolValue) Specifies if the rate limit filter should include the virtual host rate limits. By default, if the route configured rate limits, the virtual host rate_limits are not applied to the request.

hash_policy

(config.route.v3.RouteAction.HashPolicy) Specifies a list of hash policies to use for ring hash load balancing. Each hash policy is evaluated individually and the combined result is used to route the request. The method of combination is deterministic such that identical lists of hash policies will produce the same hash. Since a hash policy examines specific parts of a request, it can fail to produce a hash (i.e. if the hashed header is not present). If (and only if) all configured hash policies fail to generate a hash, no hash will be produced for the route. In this case, the behavior is the same as if no hash policies were specified (i.e. the ring hash load balancer will choose a random backend). If a hash policy has the “terminal” attribute set to true, and there is already a hash generated, the hash is returned immediately, ignoring the rest of the hash policy list.

cors

(config.route.v3.CorsPolicy) Indicates that the route has a CORS policy.

max_grpc_timeout

(Duration) If present, and the request is a gRPC request, use the grpc-timeout header, or its default value (infinity) instead of timeout, but limit the applied timeout to the maximum value specified here. If configured as 0, the maximum allowed timeout for gRPC requests is infinity. If not configured at all, the grpc-timeout header is not used and gRPC requests time out like any other requests using timeout or its default. This can be used to prevent unexpected upstream request timeouts due to potentially long time gaps between gRPC request and response in gRPC streaming mode.

Note

If a timeout is specified using x-envoy-upstream-rq-timeout-ms, it takes precedence over grpc-timeout header, when both are present. See also x-envoy-upstream-rq-timeout-ms, x-envoy-upstream-rq-per-try-timeout-ms, and the retry overview.

grpc_timeout_offset

(Duration) If present, Envoy will adjust the timeout provided by the grpc-timeout header by subtracting the provided duration from the header. This is useful in allowing Envoy to set its global timeout to be less than that of the deadline imposed by the calling client, which makes it more likely that Envoy will handle the timeout instead of having the call canceled by the client. The offset will only be applied if the provided grpc_timeout is greater than the offset. This ensures that the offset will only ever decrease the timeout and never set it to 0 (meaning infinity).

upgrade_configs

(config.route.v3.RouteAction.UpgradeConfig)

internal_redirect_action

(config.route.v3.RouteAction.InternalRedirectAction)

max_internal_redirects

(UInt32Value) An internal redirect is handled, iff the number of previous internal redirects that a downstream request has encountered is lower than this value, and internal_redirect_action is set to HANDLE_INTERNAL_REDIRECT In the case where a downstream request is bounced among multiple routes by internal redirect, the first route that hits this threshold, or has internal_redirect_action set to PASS_THROUGH_INTERNAL_REDIRECT will pass the redirect back to downstream.

If not specified, at most one redirect will be followed.

hedge_policy

(config.route.v3.HedgePolicy) Indicates that the route has a hedge policy. Note that if this is set, it’ll take precedence over the virtual host level hedge policy entirely (e.g.: policies are not merged, most internal one becomes the enforced policy).

config.route.v3.RouteAction.RequestMirrorPolicy

[config.route.v3.RouteAction.RequestMirrorPolicy proto]

The router is capable of shadowing traffic from one cluster to another. The current implementation is “fire and forget,” meaning Envoy will not wait for the shadow cluster to respond before returning the response from the primary cluster. All normal statistics are collected for the shadow cluster making this feature useful for testing.

During shadowing, the host/authority header is altered such that -shadow is appended. This is useful for logging. For example, cluster1 becomes cluster1-shadow.

Note

Shadowing will not be triggered if the primary cluster does not exist.

{
  "cluster": "...",
  "runtime_fraction": "{...}",
  "trace_sampled": "{...}"
}

cluster

(string, REQUIRED) Specifies the cluster that requests will be mirrored to. The cluster must exist in the cluster manager configuration.

runtime_fraction

(config.core.v3.RuntimeFractionalPercent) If not specified, all requests to the target cluster will be mirrored.

If specified, this field takes precedence over the runtime_key field and requests must also fall under the percentage of matches indicated by this field.

For some fraction N/D, a random number in the range [0,D) is selected. If the number is <= the value of the numerator N, or if the key is not present, the default value, the request will be mirrored.

trace_sampled

(BoolValue) Determines if the trace span should be sampled. Defaults to true.

config.route.v3.RouteAction.HashPolicy

[config.route.v3.RouteAction.HashPolicy proto]

Specifies the route’s hashing policy if the upstream cluster uses a hashing load balancer.

{
  "header": "{...}",
  "cookie": "{...}",
  "connection_properties": "{...}",
  "query_parameter": "{...}",
  "filter_state": "{...}",
  "terminal": "..."
}

header

(config.route.v3.RouteAction.HashPolicy.Header) Header hash policy.

Precisely one of header, cookie, connection_properties, query_parameter, filter_state must be set.

(config.route.v3.RouteAction.HashPolicy.Cookie) Cookie hash policy.

Precisely one of header, cookie, connection_properties, query_parameter, filter_state must be set.

connection_properties

(config.route.v3.RouteAction.HashPolicy.ConnectionProperties) Connection properties hash policy.

Precisely one of header, cookie, connection_properties, query_parameter, filter_state must be set.

query_parameter

(config.route.v3.RouteAction.HashPolicy.QueryParameter) Query parameter hash policy.

Precisely one of header, cookie, connection_properties, query_parameter, filter_state must be set.

filter_state

(config.route.v3.RouteAction.HashPolicy.FilterState) Filter state hash policy.

Precisely one of header, cookie, connection_properties, query_parameter, filter_state must be set.

terminal

(bool) The flag that short-circuits the hash computing. This field provides a ‘fallback’ style of configuration: “if a terminal policy doesn’t work, fallback to rest of the policy list”, it saves time when the terminal policy works.

If true, and there is already a hash computed, ignore rest of the list of hash polices. For example, if the following hash methods are configured:

specifier
terminal
Header A
true
Header B
false
Header C
false

specifier	terminal
Header A	true
Header B	false
Header C	false

The generateHash process ends if policy “header A” generates a hash, as it’s a terminal policy.

config.route.v3.RouteAction.HashPolicy.Header

[config.route.v3.RouteAction.HashPolicy.Header proto]

{
  "header_name": "..."
}

header_name

(string, REQUIRED) The name of the request header that will be used to obtain the hash key. If the request header is not present, no hash will be produced.

config.route.v3.RouteAction.HashPolicy.Cookie

[config.route.v3.RouteAction.HashPolicy.Cookie proto]

Envoy supports two types of cookie affinity:

Passive. Envoy takes a cookie that’s present in the cookies header and hashes on its value.
Generated. Envoy generates and sets a cookie with an expiration (TTL) on the first request from the client in its response to the client, based on the endpoint the request gets sent to. The client then presents this on the next and all subsequent requests. The hash of this is sufficient to ensure these requests get sent to the same endpoint. The cookie is generated by hashing the source and destination ports and addresses so that multiple independent HTTP2 streams on the same connection will independently receive the same cookie, even if they arrive at the Envoy simultaneously.

{
  "name": "...",
  "ttl": "{...}",
  "path": "..."
}

name

(string, REQUIRED) The name of the cookie that will be used to obtain the hash key. If the cookie is not present and ttl below is not set, no hash will be produced.

ttl

(Duration) If specified, a cookie with the TTL will be generated if the cookie is not present. If the TTL is present and zero, the generated cookie will be a session cookie.

path

(string) The name of the path for the cookie. If no path is specified here, no path will be set for the cookie.

config.route.v3.RouteAction.HashPolicy.ConnectionProperties

[config.route.v3.RouteAction.HashPolicy.ConnectionProperties proto]

{
  "source_ip": "..."
}

source_ip

(bool) Hash on source IP address.

config.route.v3.RouteAction.HashPolicy.QueryParameter

[config.route.v3.RouteAction.HashPolicy.QueryParameter proto]

{
  "name": "..."
}

name

(string, REQUIRED) The name of the URL query parameter that will be used to obtain the hash key. If the parameter is not present, no hash will be produced. Query parameter names are case-sensitive.

config.route.v3.RouteAction.HashPolicy.FilterState

[config.route.v3.RouteAction.HashPolicy.FilterState proto]

{
  "key": "..."
}

key

(string, REQUIRED) The name of the Object in the per-request filterState, which is an Envoy::Http::Hashable object. If there is no data associated with the key, or the stored object is not Envoy::Http::Hashable, no hash will be produced.

config.route.v3.RouteAction.UpgradeConfig

[config.route.v3.RouteAction.UpgradeConfig proto]

Allows enabling and disabling upgrades on a per-route basis. This overrides any enabled/disabled upgrade filter chain specified in the HttpConnectionManager upgrade_configs but does not affect any custom filter chain specified there.

{
  "upgrade_type": "...",
  "enabled": "{...}"
}

upgrade_type

(string) The case-insensitive name of this upgrade, e.g. “websocket”. For each upgrade type present in upgrade_configs, requests with Upgrade: [upgrade_type] will be proxied upstream.

enabled

(BoolValue) Determines if upgrades are available on this route. Defaults to true.

Enum config.route.v3.RouteAction.ClusterNotFoundResponseCode

[config.route.v3.RouteAction.ClusterNotFoundResponseCode proto]

SERVICE_UNAVAILABLE

(DEFAULT) ⁣HTTP status code - 503 Service Unavailable.

NOT_FOUND

⁣HTTP status code - 404 Not Found.

Enum config.route.v3.RouteAction.InternalRedirectAction

[config.route.v3.RouteAction.InternalRedirectAction proto]

Configures internal redirect behavior.

PASS_THROUGH_INTERNAL_REDIRECT

(DEFAULT) ⁣

HANDLE_INTERNAL_REDIRECT

⁣

config.route.v3.RetryPolicy

[config.route.v3.RetryPolicy proto]

HTTP retry architecture overview.

{
  "retry_on": "...",
  "num_retries": "{...}",
  "per_try_timeout": "{...}",
  "retry_priority": "{...}",
  "retry_host_predicate": [],
  "host_selection_retry_max_attempts": "...",
  "retriable_status_codes": [],
  "retry_back_off": "{...}",
  "retriable_headers": [],
  "retriable_request_headers": []
}

retry_on

(string) Specifies the conditions under which retry takes place. These are the same conditions documented for x-envoy-retry-on and x-envoy-retry-grpc-on.

num_retries

(UInt32Value) Specifies the allowed number of retries. This parameter is optional and defaults to 1. These are the same conditions documented for x-envoy-max-retries.

per_try_timeout

(Duration) Specifies a non-zero upstream timeout per retry attempt. This parameter is optional. The same conditions documented for x-envoy-upstream-rq-per-try-timeout-ms apply.

Note

If left unspecified, Envoy will use the global route timeout for the request. Consequently, when using a 5xx based retry policy, a request that times out will not be retried as the total timeout budget would have been exhausted.

retry_priority

(config.route.v3.RetryPolicy.RetryPriority) Specifies an implementation of a RetryPriority which is used to determine the distribution of load across priorities used for retries. Refer to retry plugin configuration for more details.

retry_host_predicate

(config.route.v3.RetryPolicy.RetryHostPredicate) Specifies a collection of RetryHostPredicates that will be consulted when selecting a host for retries. If any of the predicates reject the host, host selection will be reattempted. Refer to retry plugin configuration for more details.

host_selection_retry_max_attempts

(int64) The maximum number of times host selection will be reattempted before giving up, at which point the host that was last selected will be routed to. If unspecified, this will default to retrying once.

retriable_status_codes

(uint32) HTTP status codes that should trigger a retry in addition to those specified by retry_on.

retry_back_off

(config.route.v3.RetryPolicy.RetryBackOff) Specifies parameters that control retry back off. This parameter is optional, in which case the default base interval is 25 milliseconds or, if set, the current value of the upstream.base_retry_backoff_ms runtime parameter. The default maximum interval is 10 times the base interval. The documentation for x-envoy-max-retries describes Envoy’s back-off algorithm.

retriable_headers

(config.route.v3.HeaderMatcher) HTTP response headers that trigger a retry if present in the response. A retry will be triggered if any of the header matches match the upstream response headers. The field is only consulted if ‘retriable-headers’ retry policy is active.

retriable_request_headers

(config.route.v3.HeaderMatcher) HTTP headers which must be present in the request for retries to be attempted.

config.route.v3.RetryPolicy.RetryPriority

[config.route.v3.RetryPolicy.RetryPriority proto]

{
  "name": "...",
  "typed_config": "{...}"
}

name

(string, REQUIRED)

typed_config

(Any)

config.route.v3.RetryPolicy.RetryHostPredicate

[config.route.v3.RetryPolicy.RetryHostPredicate proto]

{
  "name": "...",
  "typed_config": "{...}"
}

name

(string, REQUIRED)

typed_config

(Any)

config.route.v3.RetryPolicy.RetryBackOff

[config.route.v3.RetryPolicy.RetryBackOff proto]

{
  "base_interval": "{...}",
  "max_interval": "{...}"
}

base_interval

(Duration, REQUIRED) Specifies the base interval between retries. This parameter is required and must be greater than zero. Values less than 1 ms are rounded up to 1 ms. See x-envoy-max-retries for a discussion of Envoy’s back-off algorithm.

max_interval

(Duration) Specifies the maximum interval between retries. This parameter is optional, but must be greater than or equal to the base_interval if set. The default is 10 times the base_interval. See x-envoy-max-retries for a discussion of Envoy’s back-off algorithm.

config.route.v3.HedgePolicy

[config.route.v3.HedgePolicy proto]

HTTP request hedging architecture overview.

{
  "hedge_on_per_try_timeout": "..."
}

hedge_on_per_try_timeout

(bool) Indicates that a hedged request should be sent when the per-try timeout is hit. This will only occur if the retry policy also indicates that a timed out request should be retried. Once a timed out request is retried due to per try timeout, the router filter will ensure that it is not retried again even if the returned response headers would otherwise be retried according the specified RetryPolicy. Defaults to false.

config.route.v3.RedirectAction

[config.route.v3.RedirectAction proto]

{
  "https_redirect": "...",
  "scheme_redirect": "...",
  "host_redirect": "...",
  "port_redirect": "...",
  "path_redirect": "...",
  "prefix_rewrite": "...",
  "response_code": "...",
  "strip_query": "..."
}

https_redirect

(bool) The scheme portion of the URL will be swapped with “https”.

When the scheme redirection take place, the following rules apply:
1. If the source URI scheme is http and the port is explicitly set to :80, the port will be removed after the redirection
2. If the source URI scheme is https and the port is explicitly set to :443, the port will be removed after the redirection

Only one of https_redirect, scheme_redirect may be set.

scheme_redirect

(string) The scheme portion of the URL will be swapped with this value.

When the scheme redirection take place, the following rules apply:
1. If the source URI scheme is http and the port is explicitly set to :80, the port will be removed after the redirection
2. If the source URI scheme is https and the port is explicitly set to :443, the port will be removed after the redirection

Only one of https_redirect, scheme_redirect may be set.

host_redirect

(string) The host portion of the URL will be swapped with this value.

port_redirect

(uint32) The port value of the URL will be swapped with this value.

path_redirect

(string) The path portion of the URL will be swapped with this value.

Only one of path_redirect, prefix_rewrite may be set.

prefix_rewrite

(string) Indicates that during redirection, the matched prefix (or path) should be swapped with this value. This option allows redirect URLs be dynamically created based on the request.

Attention

Pay attention to the use of trailing slashes as mentioned in RouteAction’s prefix_rewrite.

Only one of path_redirect, prefix_rewrite may be set.

response_code

(config.route.v3.RedirectAction.RedirectResponseCode) The HTTP status code to use in the redirect response. The default response code is MOVED_PERMANENTLY (301).

strip_query

(bool) Indicates that during redirection, the query portion of the URL will be removed. Default value is false.

Enum config.route.v3.RedirectAction.RedirectResponseCode

[config.route.v3.RedirectAction.RedirectResponseCode proto]

MOVED_PERMANENTLY

(DEFAULT) ⁣Moved Permanently HTTP Status Code - 301.

FOUND

⁣Found HTTP Status Code - 302.

SEE_OTHER

⁣See Other HTTP Status Code - 303.

TEMPORARY_REDIRECT

⁣Temporary Redirect HTTP Status Code - 307.

PERMANENT_REDIRECT

⁣Permanent Redirect HTTP Status Code - 308.

config.route.v3.DirectResponseAction

[config.route.v3.DirectResponseAction proto]

{
  "status": "...",
  "body": "{...}"
}

status

(uint32) Specifies the HTTP response status to be returned.

body

(config.core.v3.DataSource) Specifies the content of the response body. If this setting is omitted, no body is included in the generated response.

Note

Headers can be specified using response_headers_to_add in the enclosing config.route.v3.Route, config.route.v3.RouteConfiguration or config.route.v3.VirtualHost.

config.route.v3.Decorator

[config.route.v3.Decorator proto]

{
  "operation": "...",
  "propagate": "{...}"
}

operation

(string, REQUIRED) The operation name associated with the request matched to this route. If tracing is enabled, this information will be used as the span name reported for this request.

Note

For ingress (inbound) requests, or egress (outbound) responses, this value may be overridden by the x-envoy-decorator-operation header.

propagate

(BoolValue) Whether the decorated details should be propagated to the other party. The default is true.

config.route.v3.Tracing

[config.route.v3.Tracing proto]

{
  "client_sampling": "{...}",
  "random_sampling": "{...}",
  "overall_sampling": "{...}",
  "custom_tags": []
}

client_sampling

(type.v3.FractionalPercent) Target percentage of requests managed by this HTTP connection manager that will be force traced if the x-client-trace-id header is set. This field is a direct analog for the runtime variable ‘tracing.client_sampling’ in the HTTP Connection Manager. Default: 100%

random_sampling

(type.v3.FractionalPercent) Target percentage of requests managed by this HTTP connection manager that will be randomly selected for trace generation, if not requested by the client or not forced. This field is a direct analog for the runtime variable ‘tracing.random_sampling’ in the HTTP Connection Manager. Default: 100%

overall_sampling

(type.v3.FractionalPercent) Target percentage of requests managed by this HTTP connection manager that will be traced after all other sampling checks have been applied (client-directed, force tracing, random sampling). This field functions as an upper limit on the total configured sampling rate. For instance, setting client_sampling to 100% but overall_sampling to 1% will result in only 1% of client requests with the appropriate headers to be force traced. This field is a direct analog for the runtime variable ‘tracing.global_enabled’ in the HTTP Connection Manager. Default: 100%

custom_tags

(type.tracing.v3.CustomTag) A list of custom tags with unique tag name to create tags for the active span. It will take effect after merging with the corresponding configuration configured in the HTTP connection manager. If two tags with the same name are configured each in the HTTP connection manager and the route level, the one configured here takes priority.

config.route.v3.VirtualCluster

[config.route.v3.VirtualCluster proto]

A virtual cluster is a way of specifying a regex matching rule against certain important endpoints such that statistics are generated explicitly for the matched requests. The reason this is useful is that when doing prefix/path matching Envoy does not always know what the application considers to be an endpoint. Thus, it’s impossible for Envoy to generically emit per endpoint statistics. However, often systems have highly critical endpoints that they wish to get “perfect” statistics on. Virtual cluster statistics are perfect in the sense that they are emitted on the downstream side such that they include network level failures.

Documentation for virtual cluster statistics.

Note

Virtual clusters are a useful tool, but we do not recommend setting up a virtual cluster for every application endpoint. This is both not easily maintainable and as well the matching and statistics output are not free.

{
  "headers": [],
  "name": "..."
}

headers

(config.route.v3.HeaderMatcher) Specifies a list of header matchers to use for matching requests. Each specified header must match. The pseudo-headers :path and :method can be used to match the request path and method, respectively.

name

(string, REQUIRED) Specifies the name of the virtual cluster. The virtual cluster name as well as the virtual host name are used when emitting statistics. The statistics are emitted by the router filter and are documented here.

config.route.v3.RateLimit

[config.route.v3.RateLimit proto]

Global rate limiting architecture overview.

{
  "stage": "{...}",
  "disable_key": "...",
  "actions": []
}

stage

(UInt32Value) Refers to the stage set in the filter. The rate limit configuration only applies to filters with the same stage number. The default stage number is 0.

Note

The filter supports a range of 0 - 10 inclusively for stage numbers.

disable_key

(string) The key to be set in runtime to disable this rate limit configuration.

actions

(config.route.v3.RateLimit.Action, REQUIRED) A list of actions that are to be applied for this rate limit configuration. Order matters as the actions are processed sequentially and the descriptor is composed by appending descriptor entries in that sequence. If an action cannot append a descriptor entry, no descriptor is generated for the configuration. See composing actions for additional documentation.

config.route.v3.RateLimit.Action

[config.route.v3.RateLimit.Action proto]

{
  "source_cluster": "{...}",
  "destination_cluster": "{...}",
  "request_headers": "{...}",
  "remote_address": "{...}",
  "generic_key": "{...}",
  "header_value_match": "{...}"
}

source_cluster

(config.route.v3.RateLimit.Action.SourceCluster) Rate limit on source cluster.

Precisely one of source_cluster, destination_cluster, request_headers, remote_address, generic_key, header_value_match must be set.

destination_cluster

(config.route.v3.RateLimit.Action.DestinationCluster) Rate limit on destination cluster.

Precisely one of source_cluster, destination_cluster, request_headers, remote_address, generic_key, header_value_match must be set.

request_headers

(config.route.v3.RateLimit.Action.RequestHeaders) Rate limit on request headers.

Precisely one of source_cluster, destination_cluster, request_headers, remote_address, generic_key, header_value_match must be set.

remote_address

(config.route.v3.RateLimit.Action.RemoteAddress) Rate limit on remote address.

Precisely one of source_cluster, destination_cluster, request_headers, remote_address, generic_key, header_value_match must be set.

generic_key

(config.route.v3.RateLimit.Action.GenericKey) Rate limit on a generic key.

Precisely one of source_cluster, destination_cluster, request_headers, remote_address, generic_key, header_value_match must be set.

header_value_match

(config.route.v3.RateLimit.Action.HeaderValueMatch) Rate limit on the existence of request headers.

Precisely one of source_cluster, destination_cluster, request_headers, remote_address, generic_key, header_value_match must be set.

config.route.v3.RateLimit.Action.SourceCluster

[config.route.v3.RateLimit.Action.SourceCluster proto]

The following descriptor entry is appended to the descriptor:

("source_cluster", "<local service cluster>")

<local service cluster> is derived from the --service-cluster option.

{}

config.route.v3.RateLimit.Action.DestinationCluster

[config.route.v3.RateLimit.Action.DestinationCluster proto]

The following descriptor entry is appended to the descriptor:

("destination_cluster", "<routed target cluster>")

Once a request matches against a route table rule, a routed cluster is determined by one of the following route table configuration settings:

cluster indicates the upstream cluster to route to.
weighted_clusters chooses a cluster randomly from a set of clusters with attributed weight.
cluster_header indicates which header in the request contains the target cluster.

{}

config.route.v3.RateLimit.Action.RequestHeaders

[config.route.v3.RateLimit.Action.RequestHeaders proto]

The following descriptor entry is appended when a header contains a key that matches the header_name:

("<descriptor_key>", "<header_value_queried_from_header>")

{
  "header_name": "...",
  "descriptor_key": "..."
}

header_name

(string, REQUIRED) The header name to be queried from the request headers. The header’s value is used to populate the value of the descriptor entry for the descriptor_key.

descriptor_key

(string, REQUIRED) The key to use in the descriptor entry.

config.route.v3.RateLimit.Action.RemoteAddress

[config.route.v3.RateLimit.Action.RemoteAddress proto]

The following descriptor entry is appended to the descriptor and is populated using the trusted address from x-forwarded-for:

("remote_address", "<trusted address from x-forwarded-for>")

{}

config.route.v3.RateLimit.Action.GenericKey

[config.route.v3.RateLimit.Action.GenericKey proto]

The following descriptor entry is appended to the descriptor:

("generic_key", "<descriptor_value>")

{
  "descriptor_value": "..."
}

descriptor_value

(string, REQUIRED) The value to use in the descriptor entry.

config.route.v3.RateLimit.Action.HeaderValueMatch

[config.route.v3.RateLimit.Action.HeaderValueMatch proto]

The following descriptor entry is appended to the descriptor:

("header_match", "<descriptor_value>")

{
  "descriptor_value": "...",
  "expect_match": "{...}",
  "headers": []
}

descriptor_value

(string, REQUIRED) The value to use in the descriptor entry.

expect_match

(BoolValue) If set to true, the action will append a descriptor entry when the request matches the headers. If set to false, the action will append a descriptor entry when the request does not match the headers. The default value is true.

headers

(config.route.v3.HeaderMatcher, REQUIRED) Specifies a set of headers that the rate limit action should match on. The action will check the request’s headers against all the specified headers in the config. A match will happen if all the headers in the config are present in the request with the same values (or based on presence if the value field is not in the config).

config.route.v3.HeaderMatcher

[config.route.v3.HeaderMatcher proto]

Attention

Internally, Envoy always uses the HTTP/2 :authority header to represent the HTTP/1 Host header. Thus, if attempting to match on Host, match on :authority instead.

Attention

To route on HTTP method, use the special HTTP/2 :method header. This works for both HTTP/1 and HTTP/2 as Envoy normalizes headers. E.g.,

{
  "name": ":method",
  "exact_match": "POST"
}

Attention

In the absence of any header match specifier, match will default to present_match. i.e, a request that has the name header will match, regardless of the header’s value.

{
  "name": "...",
  "exact_match": "...",
  "safe_regex_match": "{...}",
  "range_match": "{...}",
  "present_match": "...",
  "prefix_match": "...",
  "suffix_match": "...",
  "invert_match": "..."
}

name

(string, REQUIRED) Specifies the name of the header in the request.

exact_match

(string) If specified, header match will be performed based on the value of the header.