I'm looking for a command like "gcloud config get-value project" that retrieves a project's name, but for a pod (it can retrieve any pod name that is running). I know you can get multiple pods with "kubectl get pods", but I would just like one pod name as the result.
I'm having to do this all the time:
kubectl get pods # add one of the pod names in next line
kubectl logs -f some-pod-frontend-3931629792-g589c some-app
I'm thinking along the lines of "gcloud config get-value pod". Is there a command to do that correctly?
There are many ways, here are some examples of solutions:
kubectl get pods -o name --no-headers=true
kubectl get pods -o=name --all-namespaces | grep kube-proxy
kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}'
For additional reading, please take a look to these links:
kubernetes list all running pods name
Kubernetes list all container id
https://kubernetes.io/docs/tasks/access-application-cluster/list-all-running-container-images/
You can use the grep command to filter any output on stdout. So to get pods matching a specified pattern you can use a command like this:
> kubectl get pods --all-namespaces|grep grafana
Output:
monitoring kube-prometheus-grafana-57d5b4d79f-smkz6 2/2 Running 0 1h
To only output the pod name, you can use the awk command with a parameter of '{print $2}', which displays the second column of the previous output:
kubectl get pods --all-namespaces|grep grafana|awk '{print $2}'
To only display one line you can use the head command like so:
kubectl get pods --all-namespaces|grep grafana|awk '{print $2}'|head -n 1
This will output the last pod name :
kubectl get pods -o go-template --template ' {{range .items}}{{.metadata.name}}{{"\n"}}{{end}}' | awk '{print $1}' | tail -n 1
if you want to fetch logs for a pod:
kubectl logs -f kubectl get pods -o go-template --template ' {{range .items}}{{.metadata.name}}{{"\n"}}{{end}}' | awk '{print $1}' | tail -n 1
just run the command with a single quotes.
Links:
kubernetes list all running pods name
https://kubernetes.io/docs/tasks/access-application-cluster/list-all-running-container-images/
Hope this helps!!
Related
The use case is to get the environment variable *COUNTRY from all the pods running in a namespace
kubectl get pods podname -n namespace -o 'jsonpath={.spec.containers[0].env[?(#.name~="^COUNTRY")].value}'
This does not seem to work. any lead?
You can retrieve this information using the following command:
kubectl get pods --all-namespaces -o jsonpath='{range .items[*]}{.spec.containers[*].env[*].name}{"\t"}{.spec.containers[*].env[*].value}{"\n"}{end}' | grep COUNTRY | cut -f 2
It will return the variables content as follows:
$ kubectl get pods --all-namespaces -o jsonpath='{range .items[*]}{.spec.containers[*].env[*].name}{"\t"}{.spec.containers[*].env[*].value}{"\n"}{end}' | grep VAR | cut -f 2
123456
7890123
kubectl get pods -o=jsonpath='{.items[*].spec.containers[*].env[?(#.name=="COUNTRY")].value}'
Hope this helps. I was just able to run it on mine and it worked the best.
When I am using below it deletes the running POD after matching the pattern from commandline:
kubectl get pods -n bi-dev --no-headers=true | awk '/group-react/{print $1}' | xargs kubectl delete -n bi-dev pod
However when I am using this command as an alias in .bash_profile it doesn't execute .
This is how I defined it :
alias kdpgroup="kubectl get pods -n bi-dev --no-headers=true | awk '/group-react/{print $1}'| kubectl delete -n bi-dev pod"
when execute this as below I get below error in commandline:
~ $ kdpgroup
error: resource(s) were provided, but no name, label selector, or --all flag specified
When I define this in .bash_profile I get this :
~ $ . ./.bash_profile
-bash: alias: }| xargs kubectl delete -n bi-dev pod: not found
~ $
Am I missing something to delete POD using Pattern Match or with Wilcard ?
thanks
Am I missing something to delete POD using Pattern Match or with Wilcard?
When using Kubernetes it is more common to use labels and selectors. E.g. if you deployed an application, you usually set a label on the pods e.g. app=my-app and you can then get the pods with e.g. kubectl get pods -l app=my-app.
Using this aproach, it is easier to delete the pods you are interested in, with e.g.
kubectl delete pods -l app=my-app
or with namespaces
kubectl delete pods -l app=my-app -n default
See more on Kubernetes Labels and Selectors
Set-based selector
I have some pod's running in the name of "superset-react" and "superset-graphql" and I want to search my wildcard superset and delete both of them in one command
I suggest that those pods has labels app=something-react and app=something-graphql. If you want to classify those apps, e.g. if your "superset" varies, you could add a label app-type=react and app-type=graphql to all those type of apps.
Then you can delete pods for both app types with this command:
kubectl delete pods -l 'app-type in (react, graphql)'
As the question asks, this is about using a wild card. Let me give examples on using wild cards to delete pods.
Delete Pods which contain the word "application"
Replace <namespace> with the namespace you want to delete pods from.
kubectl get pods -n <namespace> --no-headers=true | awk '/application/{print $1}'| xargs kubectl delete -n <namespace> pod
This will give a response like the following. It will print out the deleted pods.
pod "sre-application-7fb4f5bff9-8crgx" deleted
pod "sre-application-7fb4f5bff9-ftzfd" deleted
pod "sre-application-7fb4f5bff9-rrkt2" deleted
Delete Pods which contain "application" or "service"
Replace <namespace> with the namespace you want to delete pods from.
kubectl get pods -n <namespace> --no-headers=true | awk '/application|service/{print $1}'| xargs kubectl delete -n <namespace> pod
This will give a response like the following. It will print out the deleted pods.
pod "sre-application-7fb4f5bff9-8crgx" deleted
pod "sre-application-7fb4f5bff9-ftzfd" deleted
pod "sre-service-7fb4f5bff9-rrkt2" deleted
You just need to escape the '$1' variable in the awk command:
alias kdpgroup="kubectl get pods -n bi-dev --no-headers=true | awk '/group-react/{print \$1}'| xargs kubectl delete -n bi-dev pod"
I know that escape is boring, and if you want to avoid it you can use as a function in you .bash_profile:
kdpgroup() {
kubectl get pods -n default --no-headers=true | awk '{print $1}' | xargs kubectl delete pod -n default
}
A robust way with variables, based on #keetSugathadasa answer:
ns="optional-namespace"
regex="pattern"
kubectl get pods ${ns:+ -n $ns} --no-headers | awk /${regex}/'{print $1}' \
| xargs kubectl delete ${ns:+ -n $ns} pod
using grep you can filter the keyword like this and delete matching pod name like this
kubectl get pods --no-headers=true | awk '{print $1}' | grep keyword | xargs kubectl delete pod
I just saw some of my pods got evicted by kubernetes. What will happen to them? just hanging around like that or I have to delete them manually?
A quick workaround I use, is to delete all evicted pods manually after an incident. You can use this command:
kubectl get pods --all-namespaces -o json | jq '.items[] | select(.status.reason!=null) | select(.status.reason | contains("Evicted")) | "kubectl delete pods \(.metadata.name) -n \(.metadata.namespace)"' | xargs -n 1 bash -c
To delete pods in Failed state in namespace default
kubectl -n default delete pods --field-selector=status.phase=Failed
Evicted pods should be manually deleted. You can use following command to delete all pods in Error state.
kubectl get pods --all-namespaces --field-selector 'status.phase==Failed' -o json | kubectl delete -f -
Depending on if a soft or hard eviction threshold that has been met, the Containers in the Pod will be terminated with or without grace period, the PodPhase will be marked as Failed and the Pod deleted. If your Application runs as part of e.g. a Deployment, there will be another Pod created and scheduled by Kubernetes - probably on another Node not exceeding its eviction thresholds.
Be aware that eviction does not necessarily have to be caused by thresholds but can also be invoked via kubectl drain to empty a node or manually via the Kubernetes API.
To answer the original question: the evicted pods will hang around until the number of them reaches the terminated-pod-gc-threshold limit (it's an option of kube-controller-manager and is equal to 12500 by default), it's by design behavior of Kubernetes (also the same approach is used and documented for Jobs - https://kubernetes.io/docs/concepts/workloads/controllers/job/#job-termination-and-cleanup). Keeping the evicted pods pods around allows you to view the logs of those pods to check for errors, warnings, or other diagnostic output.
The bellow command delete all failed pods from all namespaces
kubectl get pods -A | grep Evicted | awk '{print $2 " -n " $1}' | xargs -n 3 kubectl delete pod
One more bash command to delete evicted pods
kubectl get pods | grep Evicted | awk '{print $1}' | xargs kubectl delete pod
Just in the case someone wants to automatically delete all evicted pods for all namespaces:
Powershell
Foreach( $x in (kubectl get po --all-namespaces --field-selector=status.phase=Failed --no-headers -o custom-columns=:metadata.name)) {kubectl delete po $x --all-namespaces }
Bash
kubectl get po --all-namespaces --field-selector=status.phase=Failed --no-headers -o custom-columns=:metadata.name | xargs kubectl delete po --all-namespaces
Kube-controller-manager exists by default with a working K8s installation. It appears that the default is a max of 12500 terminated pods before GC kicks in.
Directly from the K8s documentation:
https://kubernetes.io/docs/reference/command-line-tools-reference/kube-controller-manager/#kube-controller-manager
--terminated-pod-gc-threshold int32 Default: 12500
Number of terminated pods that can exist before the terminated pod garbage collector starts deleting terminated pods. If <= 0, the terminated pod garbage collector is disabled.
In case you have pods with a Completed status that you want to keep around:
kubectl get pods --all-namespaces --field-selector 'status.phase==Failed' -o json | kubectl delete -f -
Another way still with awk.
To prevent any human error that could make me crazy (deleting desirable pods), I check before the result of the get pods command :
kubectl -n my-ns get pods --no-headers --field-selector=status.phase=Failed
If that looks good, here we go :
kubectl -n my-ns get pods --no-headers --field-selector=status.phase=Failed | \
awk '{system("kubectl -n my-ns delete pods " $1)}'
Same thing with pods of all namespaces.
Check :
kubectl get -A pods --no-headers --field-selector=status.phase=Failed
Delete :
kubectl get -A pods --no-headers --field-selector status.phase=Failed | \
awk '{system("kubectl -n " $1 " delete pod " $2 )}'
OpenShift equivalent of Kalvin's command to delete all 'Evicted' pods:
eval "$(oc get pods --all-namespaces -o json | jq -r '.items[] | select(.status.phase == "Failed" and .status.reason == "Evicted") | "oc delete pod --namespace " + .metadata.namespace + " " + .metadata.name')"
To delete all the Evicted pods by force, you can try this one-line command:
$ kubectl get pod -A | sed -nr '/Evicted/s/(^\S+)\s+(\S+).*/kubectl -n \1 delete pod \2 --force --grace-period=0/e'
Tips: use the p modifier of s command of sed instead of e will just print the real command to do the deletion job:
$ kubectl get pod -A | sed -nr '/Evicted/s/(^\S+)\s+(\S+).*/kubectl -n \1 delete pod \2 --force --grace-period=0/p'
below command will get all evicted pods from the default namespace and delete them
kubectl get pods | grep Evicted | awk '{print$1}' | xargs -I {} kubectl delete pods/{}
Here is the 'official' guide for how to hard code the threshold(if you do not want to see too many evicted pods): kube-controll-manager
But a known problem is how to have kube-controll-manager installed...
When we have too many evicted pods in our cluster, this can lead to network load as each pod, even though it is evicted is connected to the network and in case of a cloud Kubernetes cluster, will have blocked an IP address, which can lead to exhaustion of IP addresses too if you have a fixed pool of IP addresses for your cluster.
Also, when we have too many pods in Evicted status, it becomes difficult to monitor the pods by running the kubectl get pod command as you will see too many evicted pods, which can be a bit confusing at times.
To delete and evicted pod run the following command
kubectl delete pod <podname> -n <namespace>
what if you have many evicted pods
kubectl get pod -n <namespace> | grep Evicted | awk '{print $1}' | xargs kubectl delete pod -n <namespace>
I've found jsonpath examples for testing multiple values but not extracting multiple values.
I want to get image and name from kubectl get pods.
this gets me name
kubectl get pods -o=jsonpath='{.items[*].spec.containers[*].name}' | xargs -n 1
this gets me image
kubectl get pods -o=jsonpath='{.items[*].spec.containers[*].image}' | xargs -n 1
but
kubectl get pods -o=jsonpath='{.items[*].spec.containers[*].[name,image}' | xargs -n 2
complains invalid array index image - is there a syntax for getting a list of node-adjacent values?
Use below command to get name and image:
kubectl get pods -Ao jsonpath='{range .items[*]}{#.metadata.name}{" "}{#.spec.template.spec.containers[].image}{"\n"}{end}'
It will give output like below:
name image
Useful command, I had to modify it a little to make it work (failed with -a flag). Also, I added a filter to app label and one more field to get: namespace, pod name, image
kubectl get pods --all-namespaces -o jsonpath='{range .items[*]}{#.metadata.namespace}{"\t"}{#.metadata.name}{"\t"}{#.spec.containers[*].image}{"\n"}{end}' -l app=nginx
Thanks! I had to change a little bit, but this worked for me:
#!/bin/bash
releases=$(kubectl get deployment -A --output=jsonpath='{range .items[*]}{#.metadata.namespace}{"|"}{#.metadata.name}{"\n"}{end}')
for release in $releases; do
namespace=$( echo $release | cut -d "|" -f 1)
deployment=$( echo $release | cut -d "|" -f 2)
kubectl rollout restart deployments -n "${namespace}" "${deployment}"
done
I looking for the option to list all pods name
How to do without awk (or cut). Now i'm using this command
kubectl get --no-headers=true pods -o name | awk -F "/" '{print $2}'
Personally I prefer this method because it relies only on kubectl, is not very verbose and we don't get the pod/ prefix in the output:
kubectl get pods --no-headers -o custom-columns=":metadata.name"
You can use the go templating option built into kubectl to format the output to just show the names for each pod:
kubectl get pods --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}'
Get Names of pods using -o=name Refer this cheatsheet for more.
kubectl get pods -o=name
Example output:
pod/kube-xyz-53kg5
pod/kube-xyz-jh7d2
pod/kube-xyz-subt9
To remove trailing pod/ you can use standard bash sed command
kubectl get pods -o=name | sed "s/^.\{4\}//"
Example output:
kube-xyz-53kg5
kube-pqr-jh7d2
kube-abc-s2bt9
To get podname with particular string, standard linux grep command
kubectl get pods -o=name | grep kube-pqr | sed "s/^.\{4\}//"
Example output:
kube-pqr-jh7d2
With this name, you can do things, like adding alias to get shell to running container:
alias bashkubepqr='kubectl exec -it $(kubectl get pods -o=name | grep kube-pqr | sed "s/^.\{4\}//") bash'
You can use custom-columns in output option to get the name and --no-headers option
kubectl get --no-headers=true pods -l app=external-dns -o custom-columns=:metadata.name
You can use -o=name to display only pod names. For example to list proxy pods you can use:
kubectl get pods -o=name --all-namespaces | grep kube-proxy
The result is:
pod/kube-proxy-95rlj
pod/kube-proxy-bm77b
pod/kube-proxy-clc25
There is also this solution:
kubectl get pods -o jsonpath={..metadata.name}
Here is another way to do it:
kubectl get pods -o=name --field-selector=status.phase=Running
The --field-selector=status.phase=Running is needed as the question mention all the running pod names. If the all in the question is for all the namespaces, just add the --all-namespaces option.
Note that this command is very convenient when one want a quick way to access something from the running pod(s), such as logs :
kubectl logs -f $(kubectl get pods -o=name --field-selector=status.phase=Running)
Get all running pods in the namespace
kubectl get pods --field-selector=status.phase=Running --no-headers -o custom-columns=":metadata.name"
From viewing, finding resources.
You could also specify namespace with -n <namespace name>.
jsonpath alternative
kubectl get po -o jsonpath="{range .items[*]}{#.metadata.name}{end}" -l app=nginx-ingress,component=controller
see also:
more examples of kubectl output options
If you want to extract specific container's pod name then
A simple command can do all the hard work
kubectl get pods --template '{{range .items}}{{.metadata.name}}{{end}}' --selector=app=<CONTAINER-NAME>
Just replace <CONTAINER-NAME> with your service container-name
Well, In our case we have kept pods inside different namespace, here to identify the specific pod or list of pods we ran following command-
Approach 1:
To get the list of namespaces
kubectl get ns -A
To get all the pods inside one namespaces kubectl get pods -n <namespace>
Approach 2:
Use this command-
kubectl get pods --all-namespaces
kubectl exec -it $(kubectl get pods | grep mess | awk '{print $1}') /bin/bash
kubectl get po --all-namespaces | awk '{if ($4 != "Running") system ("kubectl -n " $1 " delete pods " $2 " --grace-period=0 " " --force ")}'