Kubectl Autocomplete

Bash

source <(kubectl completion bash) # setup autocomplete in bash into the current shell, bash-completion package should be installed first.
echo "source <(kubectl completion bash)" >> ~/.bashrc # add autocomplete permanently to your bash shell.

You can also use a shorthand alias for kubectl that also works with completion:

alias k=kubectl
complete -F __start_kubectl k

ZSH

source <(kubectl completion zsh)  # setup autocomplete in zsh into the current shell
echo "[[ $commands[kubectl] ]] && source <(kubectl completion zsh)" >> ~/.zshrc # add autocomplete permanently to your zsh shell

A Note on –all-namespaces

Appending --all-namespaces happens frequently enough where you should be aware of the shorthand for --all-namespaces:

kubectl -A

Creating objects

kubectl apply -f ./my-manifest.yaml            # create resource(s)
kubectl apply -f ./my1.yaml -f ./my2.yaml      # create from multiple files
kubectl apply -f ./dir                         # create resource(s) in all manifest files in dir
kubectl apply -f https://git.io/vPieo          # create resource(s) from url
kubectl create deployment nginx --image=nginx  # start a single instance of nginx
 
# create a Job which prints "Hello World"
kubectl create job hello --image=busybox:1.28 -- echo "Hello World"
 
# create a CronJob that prints "Hello World" every minute
kubectl create cronjob hello --image=busybox:1.28   --schedule="*/1 * * * *" -- echo "Hello World"   
 
kubectl explain pods                           # get the documentation for pod manifests
 
# Create multiple YAML objects from stdin
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
  name: busybox-sleep
spec:
  containers:
  - name: busybox
    image: busybox:1.28
    args:
    - sleep
    - "1000000"
---
apiVersion: v1
kind: Pod
metadata:
  name: busybox-sleep-less
spec:
  containers:
  - name: busybox
    image: busybox:1.28
    args:
    - sleep
    - "1000"
EOF
 
# Create a secret with several keys
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Secret
metadata:
  name: mysecret
type: Opaque
data:
  password: $(echo -n "s33msi4" | base64 -w0)
  username: $(echo -n "jane" | base64 -w0)
EOF

Viewing, finding resources

# Get commands with basic output
kubectl get services                          # List all services in the namespace
kubectl get pods --all-namespaces             # List all pods in all namespaces
kubectl get pods -o wide                      # List all pods in the current namespace, with more details
kubectl get deployment my-dep                 # List a particular deployment
kubectl get pods                              # List all pods in the namespace
kubectl get pod my-pod -o yaml                # Get a pod's YAML
 
# Describe commands with verbose output
kubectl describe nodes my-node
kubectl describe pods my-pod
 
# List Services Sorted by Name
kubectl get services --sort-by=.metadata.name
 
# List pods Sorted by Restart Count
kubectl get pods --sort-by='.status.containerStatuses[0].restartCount'
 
# List PersistentVolumes sorted by capacity
kubectl get pv --sort-by=.spec.capacity.storage
 
# Get the version label of all pods with label app=cassandra
kubectl get pods --selector=app=cassandra -o \
  jsonpath='{.items[*].metadata.labels.version}'
 
# Retrieve the value of a key with dots, e.g. 'ca.crt'
kubectl get configmap myconfig \
  -o jsonpath='{.data.ca\.crt}'
 
# Get all worker nodes (use a selector to exclude results that have a label
# named 'node-role.kubernetes.io/master')
kubectl get node --selector='!node-role.kubernetes.io/master'
 
# Get all running pods in the namespace
kubectl get pods --field-selector=status.phase=Running
 
# Get ExternalIPs of all nodes
kubectl get nodes -o jsonpath='{.items[*].status.addresses[?(@.type=="ExternalIP")].address}'
 
# List Names of Pods that belong to Particular RC
# "jq" command useful for transformations that are too complex for jsonpath, it can be found at https://stedolan.github.io/jq/
sel=${$(kubectl get rc my-rc --output=json | jq -j '.spec.selector | to_entries | .[] | "\(.key)=\(.value),"')%?}
echo $(kubectl get pods --selector=$sel --output=jsonpath={.items..metadata.name})
 
# Show labels for all pods (or any other Kubernetes object that supports labelling)
kubectl get pods --show-labels
 
# Check which nodes are ready
JSONPATH='{range .items[*]}{@.metadata.name}:{range @.status.conditions[*]}{@.type}={@.status};{end}{end}' \
 && kubectl get nodes -o jsonpath="$JSONPATH" | grep "Ready=True"
 
# Output decoded secrets without external tools
kubectl get secret my-secret -o go-template='{{range $k,$v := .data}}{{"### "}}{{$k}}{{"\n"}}{{$v|base64decode}}{{"\n\n"}}{{end}}'
 
# List all Secrets currently in use by a pod
kubectl get pods -o json | jq '.items[].spec.containers[].env[]?.valueFrom.secretKeyRef.name' | grep -v null | sort | uniq
 
# List all containerIDs of initContainer of all pods
# Helpful when cleaning up stopped containers, while avoiding removal of initContainers.
kubectl get pods --all-namespaces -o jsonpath='{range .items[*].status.initContainerStatuses[*]}{.containerID}{"\n"}{end}' | cut -d/ -f3
 
# List Events sorted by timestamp
kubectl get events --sort-by=.metadata.creationTimestamp
 
# Compares the current state of the cluster against the state that the cluster would be in if the manifest was applied.
kubectl diff -f ./my-manifest.yaml
 
# Produce a period-delimited tree of all keys returned for nodes
# Helpful when locating a key within a complex nested JSON structure
kubectl get nodes -o json | jq -c 'paths|join(".")'
 
# Produce a period-delimited tree of all keys returned for pods, etc
kubectl get pods -o json | jq -c 'paths|join(".")'
 
# Produce ENV for all pods, assuming you have a default container for the pods, default namespace and the `env` command is supported.
# Helpful when running any supported command across all pods, not just `env`
for pod in $(kubectl get po --output=jsonpath={.items..metadata.name}); do echo $pod && kubectl exec -it $pod -- env; done

Updating resources

kubectl set image deployment/frontend www=image:v2               # Rolling update "www" containers of "frontend" deployment, updating the image
kubectl rollout history deployment/frontend                      # Check the history of deployments including the revision
kubectl rollout undo deployment/frontend                         # Rollback to the previous deployment
kubectl rollout undo deployment/frontend --to-revision=2         # Rollback to a specific revision
kubectl rollout status -w deployment/frontend                    # Watch rolling update status of "frontend" deployment until completion
kubectl rollout restart deployment/frontend                      # Rolling restart of the "frontend" deployment
 
 
cat pod.json | kubectl replace -f -                              # Replace a pod based on the JSON passed into stdin
 
# Force replace, delete and then re-create the resource. Will cause a service outage.
kubectl replace --force -f ./pod.json
 
# Create a service for a replicated nginx, which serves on port 80 and connects to the containers on port 8000
kubectl expose rc nginx --port=80 --target-port=8000
 
# Update a single-container pod's image version (tag) to v4
kubectl get pod mypod -o yaml | sed 's/\(image: myimage\):.*$/\1:v4/' | kubectl replace -f -
 
kubectl label pods my-pod new-label=awesome                      # Add a Label
kubectl annotate pods my-pod icon-url=http://goo.gl/XXBTWq       # Add an annotation
kubectl autoscale deployment foo --min=2 --max=10                # Auto scale a deployment "foo"

Patching resources

# Partially update a node
kubectl patch node k8s-node-1 -p '{"spec":{"unschedulable":true}}'
 
# Update a container's image; spec.containers[*].name is required because it's a merge key
kubectl patch pod valid-pod -p '{"spec":{"containers":[{"name":"kubernetes-serve-hostname","image":"new image"}]}}'
 
# Update a container's image using a json patch with positional arrays
kubectl patch pod valid-pod --type='json' -p='[{"op": "replace", "path": "/spec/containers/0/image", "value":"new image"}]'
 
# Disable a deployment livenessProbe using a json patch with positional arrays
kubectl patch deployment valid-deployment  --type json   -p='[{"op": "remove", "path": "/spec/template/spec/containers/0/livenessProbe"}]'
 
# Add a new element to a positional array
kubectl patch sa default --type='json' -p='[{"op": "add", "path": "/secrets/1", "value": {"name": "whatever" } }]'

Editing resources

kubectl edit svc/docker-registry                      # Edit the service named docker-registry
KUBE_EDITOR="nano" kubectl edit svc/docker-registry   # Use an alternative editor

Deploy a new service

To deploy a new service you need to create a manifest file.

kubectl apply -f manifest.yaml

Delete a service

$ kubectl delete -f manifest.yaml
 
# OR
 
kubectl delete deployment <DEPLOYMENT_NAME>
kubectl delete svc <SERVICE_NAME>
kubectl delete ing <INGRESS_NAME>
kubectl delete pv <PERSISTENT_VOLUME_NAME>
kubectl delete pvc <PERSISTENT_VOLUME_CLAIM_NAME>

Interacting with running Pods

kubectl logs my-pod                                 # dump pod logs (stdout)
kubectl logs -l name=myLabel                        # dump pod logs, with label name=myLabel (stdout)
kubectl logs my-pod --previous                      # dump pod logs (stdout) for a previous instantiation of a container
kubectl logs my-pod -c my-container                 # dump pod container logs (stdout, multi-container case)
kubectl logs -l name=myLabel -c my-container        # dump pod logs, with label name=myLabel (stdout)
kubectl logs my-pod -c my-container --previous      # dump pod container logs (stdout, multi-container case) for a previous instantiation of a container
kubectl logs -f my-pod                              # stream pod logs (stdout)
kubectl logs -f my-pod -c my-container              # stream pod container logs (stdout, multi-container case)
kubectl logs -f -l name=myLabel --all-containers    # stream all pods logs with label name=myLabel (stdout)
kubectl run -i --tty busybox --image=busybox:1.28 -- sh  # Run pod as interactive shell
kubectl run nginx --image=nginx -n mynamespace      # Start a single instance of nginx pod in the namespace of mynamespace
kubectl run nginx --image=nginx                     # Run pod nginx and write its spec into a file called pod.yaml
--dry-run=client -o yaml > pod.yaml
 
kubectl attach my-pod -i                            # Attach to Running Container
kubectl port-forward my-pod 5000:6000               # Listen on port 5000 on the local machine and forward to port 6000 on my-pod
kubectl exec my-pod -- ls /                         # Run command in existing pod (1 container case)
kubectl exec --stdin --tty my-pod -- /bin/sh        # Interactive shell access to a running pod (1 container case)
kubectl exec my-pod -c my-container -- ls /         # Run command in existing pod (multi-container case)
kubectl top pod POD_NAME --containers               # Show metrics for a given pod and its containers
kubectl top pod POD_NAME --sort-by=cpu              # Show metrics for a given pod and sort it by 'cpu' or 'memory'

Scaling resources

kubectl scale --replicas=3 rs/foo                                 # Scale a replicaset named 'foo' to 3
kubectl scale --replicas=3 -f foo.yaml                            # Scale a resource specified in "foo.yaml" to 3
kubectl scale --current-replicas=2 --replicas=3 deployment/mysql  # If the deployment named mysql's current size is 2, scale mysql to 3
kubectl scale --replicas=5 rc/foo rc/bar rc/baz                   # Scale multiple replication controllers

Copy files and directories to and from containers

kubectl cp /tmp/foo_dir my-pod:/tmp/bar_dir            # Copy /tmp/foo_dir local directory to /tmp/bar_dir in a remote pod in the current namespace
kubectl cp /tmp/foo my-pod:/tmp/bar -c my-container    # Copy /tmp/foo local file to /tmp/bar in a remote pod in a specific container
kubectl cp /tmp/foo my-namespace/my-pod:/tmp/bar       # Copy /tmp/foo local file to /tmp/bar in a remote pod in namespace my-namespace
kubectl cp my-namespace/my-pod:/tmp/foo /tmp/bar       # Copy /tmp/foo from a remote pod to /tmp/bar locally

Note: kubectl cp requires that the ‘tar’ binary is present in your container image. If ‘tar’ is not present, kubectl cp will fail. For advanced use cases, such as symlinks, wildcard expansion or file mode preservation consider using kubectl exec.

tar cf - /tmp/foo | kubectl exec -i -n my-namespace my-pod -- tar xf - -C /tmp/bar           # Copy /tmp/foo local file to /tmp/bar in a remote pod in namespace my-namespace
kubectl exec -n my-namespace my-pod -- tar cf - /tmp/foo | tar xf - -C /tmp/bar    # Copy /tmp/foo from a remote pod to /tmp/bar locally

Interacting with Deployments and Services

kubectl logs deploy/my-deployment                         # dump Pod logs for a Deployment (single-container case)
kubectl logs deploy/my-deployment -c my-container         # dump Pod logs for a Deployment (multi-container case)
 
kubectl port-forward svc/my-service 5000                  # listen on local port 5000 and forward to port 5000 on Service backend
kubectl port-forward svc/my-service 5000:my-service-port  # listen on local port 5000 and forward to Service target port with name <my-service-port>
 
kubectl port-forward deploy/my-deployment 5000:6000       # listen on local port 5000 and forward to port 6000 on a Pod created by <my-deployment>
kubectl exec deploy/my-deployment -- ls                   # run command in first Pod and first container in Deployment (single- or multi-container cases)

Interacting with Nodes and cluster

kubectl cordon my-node                                                # Mark my-node as unschedulable
kubectl drain my-node                                                 # Drain my-node in preparation for maintenance
kubectl uncordon my-node                                              # Mark my-node as schedulable
kubectl top node my-node                                              # Show metrics for a given node
kubectl cluster-info                                                  # Display addresses of the master and services
kubectl cluster-info dump                                             # Dump current cluster state to stdout
kubectl cluster-info dump --output-directory=/path/to/cluster-state   # Dump current cluster state to /path/to/cluster-state
 
# If a taint with that key and effect already exists, its value is replaced as specified.
kubectl taint nodes foo dedicated=special-user:NoSchedule

Resource types

kubectl api-resources
kubectl api-resources --namespaced=true      # All namespaced resources
kubectl api-resources --namespaced=false     # All non-namespaced resources
kubectl api-resources -o name                # All resources with simple output (only the resource name)
kubectl api-resources -o wide                # All resources with expanded (aka "wide") output
kubectl api-resources --verbs=list,get       # All resources that support the "list" and "get" request verbs
kubectl api-resources --api-group=extensions # All resources in the "extensions" API group

Formatting output

To output details to your terminal window in a specific format, add the -o (or --output) flag to a supported kubectl command.

Output format	Description
Output format	Description
-o=custom-columns=	Print a table using a comma separated list of custom columns
-o=custom-columns-file=	Print a table using the custom columns template in the file
-o=json	Output a JSON formatted API object
-o=jsonpath=	Print the fields defined in a jsonpath expression
-o=jsonpath-file=	Print the fields defined by the jsonpath expression in the file
-o=name	Print only the resource name and nothing else
-o=wide	Output in the plain-text format with any additional information, and for pods, the node name is included
-o=yaml	Output a YAML formatted API object

# All images running in a cluster
kubectl get pods -A -o=custom-columns='DATA:spec.containers[*].image'
 
# All images running in namespace: default, grouped by Pod
kubectl get pods --namespace default --output=custom-columns="NAME:.metadata.name,IMAGE:.spec.containers[*].image"
 
 # All images excluding "k8s.gcr.io/coredns:1.6.2"
kubectl get pods -A -o=custom-columns='DATA:spec.containers[?(@.image!="k8s.gcr.io/coredns:1.6.2")].image'
 
# All fields under metadata regardless of name
kubectl get pods -A -o=custom-columns='DATA:metadata.*'

Kubectl output verbosity and debugging

Kubectl verbosity is controlled with the -v or --v flags followed by an integer representing the log level. General Kubernetes logging conventions and the associated log levels are described here.

Verbosity	Description
–v=0	Generally useful for this to always be visible to a cluster operator.
–v=1	A reasonable default log level if you don’t want verbosity.
–v=2	Useful steady state information about the service and important log messages that may correlate to significant changes in the system. This is the recommended default log level for most systems.
–v=3	Extended information about changes.
–v=4	Debug level verbosity.
–v=5	Trace level verbosity.
–v=6	Display requested resources.
–v=7	Display HTTP request headers.
–v=8	Display HTTP request contents.
–v=9	Display HTTP request contents without truncation of contents.