Authorization Policy

Istio Authorization Policy enables access control on workloads in the mesh.

Authorization policy supports both allow and deny policies. When allow and deny policies are used for a workload at the same time, the deny policies are evaluated first. The evaluation is determined by the following rules:

1. If there are any DENY policies that match the request, deny the request.
2. If there are no ALLOW policies for the workload, allow the request.
3. If any of the ALLOW policies match the request, allow the request.
4. Deny the request.

For example, the following authorization policy sets the action to “ALLOW” to create an allow policy. The default action is “ALLOW” but it is useful to be explicit in the policy.

It allows requests from:

• service account “cluster.local/ns/default/sa/sleep” or
• namespace “test”

to access the workload with:

• “GET” method at paths of prefix “/info” or,
• “POST” method at path “/data”.

when the request has a valid JWT token issued by “https://accounts.google.com”.

Any other requests will be denied.

apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
 name: httpbin
 namespace: foo
spec:
 action: ALLOW
 rules:
 - from:
   - source:
       principals: ["cluster.local/ns/default/sa/sleep"]
   - source:
       namespaces: ["test"]
   to:
   - operation:
       methods: ["GET"]
       paths: ["/info*"]
   - operation:
       methods: ["POST"]
       paths: ["/data"]
   when:
   - key: request.auth.claims[iss]
     values: ["https://accounts.google.com"]

The following is another example that sets action to “DENY” to create a deny policy. It denies requests from the “dev” namespace to the “POST” method on all workloads in the “foo” namespace.

apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
 name: httpbin
 namespace: foo
spec:
 action: DENY
 rules:
 - from:
   - source:
       namespaces: ["dev"]
   to:
   - operation:
       methods: ["POST"]

Authorization Policy scope (target) is determined by “metadata/namespace” and an optional “selector”.

• “metadata/namespace” tells which namespace the policy applies. If set to root namespace, the policy applies to all namespaces in a mesh.
• workload “selector” can be used to further restrict where a policy applies.

For example,

The following authorization policy applies to workloads containing label “app: httpbin” in namespace bar.

apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
 name: policy
 namespace: bar
spec:
 selector:
   matchLabels:
     app: httpbin

The following authorization policy applies to all workloads in namespace foo.

apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
 name: policy
 namespace: foo
spec:
  {}

The following authorization policy applies to workloads containing label “version: v1” in all namespaces in the mesh. (Assuming the root namespace is configured to “istio-config”).

apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
 name: policy
 namespace: istio-config
spec:
 selector:
   matchLabels:
     version: v1

AuthorizationPolicy

AuthorizationPolicy enables access control on workloads.

For example, the following authorization policy denies all requests to workloads in namespace foo.

apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
 name: deny-all
 namespace: foo
spec:
  {}

The following authorization policy allows all requests to workloads in namespace foo.

apiVersion: security.istio.io/v1beta1
kind: AuthorizationPolicy
metadata:
 name: allow-all
 namespace: foo
spec:
 rules:
 - {}

Rule

Rule matches requests from a list of sources that perform a list of operations subject to a list of conditions. A match occurs when at least one source, operation and condition matches the request. An empty rule is always matched.

Any string field in the rule supports Exact, Prefix, Suffix and Presence match:

• Exact match: “abc” will match on value “abc”.
• Prefix match: “abc*” will match on value “abc” and “abcd”.
• Suffix match: “*abc” will match on value “abc” and “xabc”.
• Presence match: “*” will match when value is not empty.

Source

Source specifies the source identities of a request. Fields in the source are ANDed together.

For example, the following source matches if the principal is “admin” or “dev” and the namespace is “prod” or “test” and the ip is not “1.2.3.4”.

principals: ["admin", "dev"]
namespaces: ["prod", "test"]
not_ipblocks: ["1.2.3.4"]

Operation

Operation specifies the operations of a request. Fields in the operation are ANDed together.

For example, the following operation matches if the host has suffix “.example.com” and the method is “GET” or “HEAD” and the path doesn’t have prefix “/admin”.

hosts: ["*.example.com"]
methods: ["GET", "HEAD"]
not_paths: ["/admin*"]

Condition

Condition specifies additional required attributes.

Rule.From

From includes a list or sources.

Rule.To

To includes a list or operations.

AuthorizationPolicy.Action

Action specifies the operation to take.