kubectl debug

Synopsis

Debug cluster resources using interactive debugging containers.

‘debug’ provides automation for common debugging tasks for cluster objects identified by resource and name. Pods will be used by default if no resource is specified.

The action taken by ‘debug’ varies depending on what resource is specified. Supported actions include:

  • Workload: Create a copy of an existing pod with certain attributes changed, for example changing the image tag to a new version.
  • Workload: Add an ephemeral container to an already running pod, for example to add debugging utilities without restarting the pod.
  • Node: Create a new pod that runs in the node’s host namespaces and can access the node’s filesystem.
  1. kubectl debug (POD | TYPE[[.VERSION].GROUP]/NAME) [ -- COMMAND [args...] ]

Examples

  1.   # Create an interactive debugging session in pod mypod and immediately attach to it.
  2.   kubectl debug mypod -it --image=busybox
  4.   # Create an interactive debugging session for the pod in the file pod.yaml and immediately attach to it.
  5.   # (requires the EphemeralContainers feature to be enabled in the cluster)
  6.   kubectl debug -f pod.yaml -it --image=busybox
  8.   # Create a debug container named debugger using a custom automated debugging image.
  9.   kubectl debug --image=myproj/debug-tools -c debugger mypod
  11.   # Create a copy of mypod adding a debug container and attach to it
  12.   kubectl debug mypod -it --image=busybox --copy-to=my-debugger
  14.   # Create a copy of mypod changing the command of mycontainer
  15.   kubectl debug mypod -it --copy-to=my-debugger --container=mycontainer -- sh
  17.   # Create a copy of mypod changing all container images to busybox
  18.   kubectl debug mypod --copy-to=my-debugger --set-image=*=busybox
  20.   # Create a copy of mypod adding a debug container and changing container images
  21.   kubectl debug mypod -it --copy-to=my-debugger --image=debian --set-image=app=app:debug,sidecar=sidecar:debug
  23.   # Create an interactive debugging session on a node and immediately attach to it.
  24.   # The container will run in the host namespaces and the host's filesystem will be mounted at /host
  25.   kubectl debug node/mynode -it --image=busybox

Options

—arguments-only

If specified, everything after — will be passed to the new container as Args instead of Command.

—attach

If true, wait for the container to start running, and then attach as if ‘kubectl attach …’ were called. Default false, unless ‘-i/—stdin’ is set, in which case the default is true.

-c, —container string

Container name to use for debug container.

—copy-to string

Create a copy of the target Pod with this name.

—env stringToString     Default: []

Environment variables to set in the container.

-f, —filename strings

identifying the resource to debug

-h, —help

help for debug

—image string

Container image to use for debug container.

—image-pull-policy string

The image pull policy for the container. If left empty, this value will not be specified by the client and defaulted by the server.

—profile string     Default: “legacy”

Options are “legacy”, “general”, “baseline”, “netadmin”, “restricted” or “sysadmin”.

-q, —quiet

If true, suppress informational messages.

—replace

When used with ‘—copy-to’, delete the original Pod.

—same-node

When used with ‘—copy-to’, schedule the copy of target Pod on the same node.

—set-image stringToString     Default: []

When used with ‘—copy-to’, a list of name=image pairs for changing container images, similar to how ‘kubectl set image’ works.

—share-processes     Default: true

When used with ‘—copy-to’, enable process namespace sharing in the copy.

-i, —stdin

Keep stdin open on the container(s) in the pod, even if nothing is attached.

—target string

When using an ephemeral container, target processes in this container name.

-t, —tty

Allocate a TTY for the debugging container.

—as string

Username to impersonate for the operation. User could be a regular user or a service account in a namespace.

—as-group strings

Group to impersonate for the operation, this flag can be repeated to specify multiple groups.

—as-uid string

UID to impersonate for the operation.

—cache-dir string     Default: “$HOME/.kube/cache”

Default cache directory

—certificate-authority string

Path to a cert file for the certificate authority

—client-certificate string

Path to a client certificate file for TLS

—client-key string

Path to a client key file for TLS

—cloud-provider-gce-l7lb-src-cidrs cidrs     Default: 130.211.0.0/22,35.191.0.0/16

CIDRs opened in GCE firewall for L7 LB traffic proxy & health checks

—cloud-provider-gce-lb-src-cidrs cidrs     Default: 130.211.0.0/22,209.85.152.0/22,209.85.204.0/22,35.191.0.0/16

CIDRs opened in GCE firewall for L4 LB traffic proxy & health checks

—cluster string

The name of the kubeconfig cluster to use

—context string

The name of the kubeconfig context to use

—default-not-ready-toleration-seconds int     Default: 300

Indicates the tolerationSeconds of the toleration for notReady:NoExecute that is added by default to every pod that does not already have such a toleration.

—default-unreachable-toleration-seconds int     Default: 300

Indicates the tolerationSeconds of the toleration for unreachable:NoExecute that is added by default to every pod that does not already have such a toleration.

—disable-compression

If true, opt-out of response compression for all requests to the server

—insecure-skip-tls-verify

If true, the server’s certificate will not be checked for validity. This will make your HTTPS connections insecure

—kubeconfig string

Path to the kubeconfig file to use for CLI requests.

—match-server-version

Require server version to match client version

-n, —namespace string

If present, the namespace scope for this CLI request

—password string

Password for basic authentication to the API server

—profile-output string     Default: “profile.pprof”

Name of the file to write the profile to

—request-timeout string     Default: “0”

The length of time to wait before giving up on a single server request. Non-zero values should contain a corresponding time unit (e.g. 1s, 2m, 3h). A value of zero means don’t timeout requests.

-s, —server string

The address and port of the Kubernetes API server

—storage-driver-buffer-duration duration     Default: 1m0s

Writes in the storage driver will be buffered for this duration, and committed to the non memory backends as a single transaction

—storage-driver-db string     Default: “cadvisor”

database name

—storage-driver-host string     Default: “localhost:8086”

database host:port

—storage-driver-password string     Default: “root”

database password

—storage-driver-secure

use secure connection with database

—storage-driver-table string     Default: “stats”

table name

—storage-driver-user string     Default: “root”

database username

—tls-server-name string

Server name to use for server certificate validation. If it is not provided, the hostname used to contact the server is used

—token string

Bearer token for authentication to the API server

—user string

The name of the kubeconfig user to use

—username string

Username for basic authentication to the API server

—version version[=true]

—version, —version=raw prints version information and quits; —version=vX.Y.Z… sets the reported version

—warnings-as-errors

Treat warnings received from the server as errors and exit with a non-zero exit code

See Also

  • kubectl - kubectl controls the Kubernetes cluster manager