Cheatography
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Kubernetes - kubectl Cheatsheet
This is a draft cheat sheet. It is a work in progress and is not finished yet.
Kubectl Autocomplete
# setup autocomplete in bash |
source <(kubectl completion bash) |
# setup autocomplete in zsh |
source <(kubectl completion zsh) |
Kubectl Context and Configuration
# Show Merged kubeconfig settings. |
kubectl config view |
# use multiple kubeconfig files at the same time and view merged config |
KUBECONFIG=/.kube/config:/.kube/kubconfig2 kubectl config view |
# Get the password for the e2e user |
kubectl config view -o jsonpath='{.users[?(@.name == "e2e")].user.password}' |
# Display the current-context |
kubectl config current-context |
# set the default context to my-cluster-name |
kubectl config use-context my-cluster-name |
# add a new cluster to your kubeconf that supports basic auth |
kubectl config set-credentials kubeuser/foo.kubernetes.com --username=kubeuser --password=kubepassword |
set a context utilizing a specific username and namespace. |
kubectl config set-context gce --user=cluster-admin --namespace=foo
\&& kubectl config use-context gce |
Updating Resources
# Rolling update pods of frontend-v1 |
kubectl rolling-update frontend-v1 -f frontend-v2.json |
# Change the name of the resource and update the image |
kubectl rolling-update frontend-v1 frontend-v2 --image=image:v2 |
# Update the pods image of frontend |
kubectl rolling-update frontend --image=image:v2 |
# Abort existing rollout in progress |
kubectl rolling-update frontend-v1 frontend-v2 --rollback |
# Replace a pod based on the JSON passed into stdin |
cat pod.json | kubectl replace -f - |
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# Force replace, delete and then re-create the resource. Will cause a service outage. |
$ kubectl replace --force -f ./pod.json |
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# 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 |
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# 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 - |
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# Add a Label |
kubectl label pods my-pod new-label=awesome |
# Add an annotation |
kubectl annotate pods my-pod icon-url=http://goo.gl/XXBTWq |
# Auto scale a deployment "foo" |
kubectl autoscale deployment foo --min=2 --max=10 |
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Creating Objects
# create resource(s) |
kubectl create -f ./my-manifest.yaml |
# create from multiple files |
kubectl create -f ./my1.yaml -f ./my2.yaml |
# create resource(s) in all manifest files in dir |
kubectl create -f ./dir |
# create resource(s) from url |
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# start a single instance of nginx |
kubectl run nginx --image=nginx |
# get the documentation for pod and svc manifests |
kubectl explain pods,svc |
# Create multiple YAML objects from stdin |
cat <<EOF | kubectl create -f -
apiVersion: v1
kind: Pod
metadata:
name: busybox-sleep
spec:
containers:
- name: busybox
image: busybox
args:
- sleep
- "1000000"
---
apiVersion: v1
kind: Pod
metadata:
name: busybox-sleep-less
spec:
containers:
- name: busybox
image: busybox
args:
- sleep
- "1000"
EOF |
# Create a secret with several keys |
cat <<EOF | kubectl create -f -
apiVersion: v1
kind: Secret
metadata:
name: mysecret
type: Opaque
data:
password: $(echo "s33msi4" | base64)
username: $(echo "jane" | base64)
EOF |
Viewing, Finding Resources
# List all services in the namespace |
kubectl get services |
# List all pods in all namespaces |
kubectl get pods --all-namespaces |
# List all pods in the namespace, with more details |
kubectl get pods -o wide |
# List a particular deployment |
kubectl get deployment my-dep |
# Describe commands with verbose output |
kubectl describe nodes my-node
kubectl describe pods my-pod |
# List Services Sorted by Name |
kubectl get services --sort-by=.metadata.name |
# List pods Sorted by Restart Count |
kubectl get pods --sort-by='.status.containerStatuses[0].restartCount' |
# Get the version label of all pods with label app=cassandra |
kubectl get pods --selector=app=cassandra rc -o \
jsonpath='{.items[*].metadata.labels.version}' |
# Get ExternalIPs of all nodes |
kubectl get nodes -o jsonpath='{.items[*].status.addresses[?(@.type=="ExternalIP")].address}' |
# List Names of Pods that belong to Particular RC |
# "jq" command useful for transformations that are too complex for jsonpath |
sel=${$(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}) |
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" |
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