Retriving the pods name , the associated images and a label attribute - kubernetes

I know I can get the pods using:
kubectl get pods -n "namespace", and also to retrieve a json output
I'm trying to expand to get the pods name, the associated images, and a label attribute called 'base'. Also the date when I retrieve this information.

You can try this using yaml output.
kubectl get pods --all-namespaces -o yaml| egrep "name:|image:"
This will give you name of pod and image which is there for running the pod.
OR
kubectl get pods --all-namespaces -o jsonpath="{.items[*].spec.containers[*].image}"
This command will give you all images which are there in all pods.
If you found this is difficult then use,
kubectl get pod --all-namespaces
Check which pods image you need to find then use,
kubectl describe pod <pod_name> -n <namespace>
For reference use Link

Here you can find the description of kubectl get command.
What are you looking for is this:
output o Output format. One of:
json|yaml|wide|name|custom-columns=...|custom-columns-file=...|go-template=...|go-template-file=...|jsonpath=...|jsonpath-file=...
See custom columns
[http://kubernetes.io/docs/user-guide/kubectl-overview/#custom-columns],
golang template [http://golang.org/pkg/text/template/#pkg-overview]
and jsonpath template [http://kubernetes.io/docs/user-guide/jsonpath].
For example:
List a pod identified by type and name specified in "pod.yaml" in JSON
output format:
kubectl get -f pod.yaml -o json
Adjust by using the flags that you need from there.
Please let me know if that helped.

You can try jsonpath to retrieve the values for json output.
kubectl get po --all-namespaces -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[0].image}{"\t"}{.metadata.labels.k8s-app}{"\n"}{end}'

probably you can write shell script and achieve this. first try to get all running pods across all namespaces using:
kubectl get pods -all-namespaces
and then iterate over each pod and execute following command:
kubectl describe pods <name of pod>
In the describe command you can get all information that you are looking for.

Related

combine multiple column output in kubectl using custom-columns or jsonpath

This is the output with custom-columns
$ kubectl -n web get pod -ocustom-columns="Name:.metadata.name,Image:.spec.containers[0].image"
Name Image
mysql-0 myrepo.mydomain.com/mysql:5.7
mysql-1 myrepo.mydomain.com/mysql:5.7
mysql-2 myrepo.mydomain.com/mysql:5.7
This is the output with jsonpath for single pod
$ kubectl -n web get pod -o jsonpath="{..metadata.name}:{..spec.containers[0].image}" mysql-0
mysql-0:myrepo.mydomain.com/mysql:5.7
This is the output with jsonpath for multiple pods
$ kubectl -n web get pod -o jsonpath="{..metadata.name}:{..spec.containers[0].image}"
mysql-0 mysql-1 mysql-2:myrepo.mydomain.com/mysql:5.7 myrepo.mydomain.com/mysql:5.7 myrepo.mydomain.com/mysql:5.7
Now how to combine this into a single column or word, something like this, using -ocustom-columns or -ojsonpath
mysql-0=myrepo.mydomain.com/mysql:5.7
mysql-1=myrepo.mydomain.com/mysql:5.7
mysql-2=myrepo.mydomain.com/mysql:5.7
Using kubectl using plain jsonpath:
kubectl get pod -n <namespace> -o jsonpath='{range .items[*]}{.metadata.name}={.spec.containers[*].image}{"\n"}{end}'
Example:
kubectl get pod -n default -o jsonpath='{range .items[*]}{.metadata.name}={.spec.containers[*].image}{"\n"}{end}'
nginx-0=nginx
nginx-1=nginx
nginx-2=nginx
Here range feature is used to loop over all the pods:
{range items[*]} ...<LOGIC HERE>... {end}
Between the range block(As described above), use the jsonpath, notice the = sign is used as per our requirement.
{.metadata.name}={.spec.containers[*].image}{"\n"}

jsonpath with kubectl to get "app.kuberentes.io/version" value

I need to get the metadata->labels->app.kubernetes.io/version value from my pods. But I can't seem to find the jsonpath that will allow the label key to have the slash and periods.
I have a basic command that is working: kubectl get pods -o=jsonpath="{range .items[*]}{.metadata.name}{end}" -A. This successfully returns name of each pods.
I have modified this to try to get the version. Here are the permutations that I have attempted (each has failed):
kubectl get pods -o=jsonpath="{range .items[*]}{.metadata.labels.app.kubernetes.io/version}{end}" -A
and
kubectl get pods -o=jsonpath="{range .items[*]}{.metadata.labels.'app.kubernetes.io/version'}{end}" -A
and
kubectl get pods -o=jsonpath="{range .items[*]}{.metadata.labels.`"app.kubernetes.io`/version`"}{end}" -A
How can I get the version using jsonpath?
I am running in Windows PowerShell if that matters
Escape dots in key name:
.metadata.labels.app\.kubernetes\.io/version
kubectl get pods -o=jsonpath="{range .items[*]}{.metadata.labels.app\.kubernetes\.io/version}{end}" -A

get name of the pod consuming highest cpu using kubectl command

I am trying to get the pod name with highest CPU utilization using kubectl command.
Able to retrieve list using following command but unable to write a jsonpath query to fetch the name of first pod from the output.
Appreciate any help in this regard. Thanks!
kubectl top pod POD_NAME --sort-by=cpu
kubectl top doesn't appear to enable --output formatting and so no JSON and thus no JSONPath :-(
You can:
kubectl top pod \
--sort-by=cpu \
--no-headers \
--namespace=${NAMESPACE} \
| head -n 1
I think it would be useful to support --output for all kubectl commands and you may wish to submit a feature request for this.
NOTE Hmmm kubectl top output format options

Not able to fetch ip address of pods using Kubectl and jsonpath

I'm trying to get the ip address of pods with particular label using jsonpath with the following command:
kubectl get pods -l app=validate -n {namespace_name} -o jsonpath={.status.podIP}
But this doesn't result into anything, even though the namespace and label names are correct. On the other hand, if I try to do:
kubectl get pod/pod_name -n {namespace_name} -o jsonpath={.status.podIP}
I'm able to get the pod IP address after that. But the problem is, since I'm trying to query all the pods created for a particular deployment, I want to fetch Ip addresses for all the pods under that particular label. I'm not sure what is wrong with the command.
If you have multiple Pods with the same label, you get a list of Pods. You have to adjust your jsonpath to -o jsonpath="{.items[*].status.podIP}" to get all the podIPs.
According to the official doc, you can add custom columns when querying a list of resources.
So you can do kubectl get pods -l app=validate -n {namespace_name} -o custom-columns=ip:.status.podIP

How do you cleanly list all the containers in a kubernetes pod?

I am looking to list all the containers in a pod in a script that gather's logs after running a test. kubectl describe pods -l k8s-app=kube-dns returns a lot of info, but I am just looking for a return like:
etcd
kube2sky
skydns
I don't see a simple way to format the describe output. Is there another command? (and I guess worst case there is always parsing the output of describe).
Answer
kubectl get pods POD_NAME_HERE -o jsonpath='{.spec.containers[*].name}'
Explanation
This gets the JSON object representing the pod. It then uses kubectl's JSONpath to extract the name of each container from the pod.
You can use get and choose one of the supported output template with the --output (-o) flag.
Take jsonpath for example,
kubectl get pods -l k8s-app=kube-dns -o jsonpath={.items[*].spec.containers[*].name} gives you etcd kube2sky skydns.
Other supported output output templates are go-template, go-template-file, jsonpath-file. See http://kubernetes.io/docs/user-guide/jsonpath/ for how to use jsonpath template. See https://golang.org/pkg/text/template/#pkg-overview for how to use go template.
Update: Check this doc for other example commands to list container images: https://kubernetes.io/docs/tasks/access-application-cluster/list-all-running-container-images/
Quick hack to avoid constructing the JSONpath query for a single pod:
$ kubectl logs mypod-123
a container name must be specified for pod mypod-123, choose one of: [etcd kubesky skydns]
I put some ideas together into the following:
Simple line:
kubectl get po -o jsonpath='{range .items[*]}{"pod: "}{.metadata.name}{"\n"}{range .spec.containers[*]}{"\tname: "}{.name}{"\n\timage: "}{.image}{"\n"}{end}'
Split (for readability):
kubectl get po -o jsonpath='
{range .items[*]}
{"pod: "}
{.metadata.name}
{"\n"}{range .spec.containers[*]}
{"\tname: "}
{.name}
{"\n\timage: "}
{.image}
{"\n"}
{end}'
How to list BOTH init and non-init containers for all pods
kubectl get pod -o="custom-columns=NAME:.metadata.name,INIT-CONTAINERS:.spec.initContainers[*].name,CONTAINERS:.spec.containers[*].name"
Output looks like this:
NAME INIT-CONTAINERS CONTAINERS
helm-install-traefik-sjts9 <none> helm
metrics-server-86cbb8457f-dkpqm <none> metrics-server
local-path-provisioner-5ff76fc89d-vjs6l <none> local-path-provisioner
coredns-6488c6fcc6-zp9gv <none> coredns
svclb-traefik-f5wwh <none> lb-port-80,lb-port-443
traefik-6f9cbd9bd4-pcbmz <none> traefik
dc-postgresql-0 init-chmod-data dc-postgresql
backend-5c4bf48d6f-7c8c6 wait-for-db backend
if you want a clear output of which containers are from each Pod
kubectl get po -l k8s-app=kube-dns \
-o=custom-columns=NAME:.metadata.name,CONTAINERS:.spec.containers[*].name
To get the output in the separate lines:
kubectl get pods POD_NAME_HERE -o jsonpath='{range .spec.containers[*]}{.name}{"\n"}{end}'
Output:
base-container
sidecar-0
sidecar-1
sidecar-2
If you use json as output format of kubectl get you get plenty details of a pod. With json processors like jq it is easy to select or filter for certain parts you are interested in.
To list the containers of a pod the jq query looks like this:
kubectl get --all-namespaces --selector k8s-app=kube-dns --output json pods \
| jq --raw-output '.items[].spec.containers[].name'
If you want to see all details regarding one specific container try something like this:
kubectl get --all-namespaces --selector k8s-app=kube-dns --output json pods \
| jq '.items[].spec.containers[] | select(.name=="etcd")'
Use below command:
kubectl get pods -o=custom-columns=PodName:.metadata.name,Containers:.spec.containers[*].name,Image:.spec.containers[*].image
To see verbose information along with configmaps of all containers in a particular pod, use this command:
kubectl describe pod/<pod name> -n <namespace name>
Use below command to see all the information of a particular pod
kubectl get pod <pod name> -n <namespace name> -o yaml
For overall details about the pod try following command to get the container details as well
kubectl describe pod <podname>
I use this to display image versions on the pods.
kubectl get pods -o=jsonpath='{range .items[*]}{"\n"}{.metadata.name}{":\t"}{range .spec.containers[*]}{.image}{end}{end}' && printf '\n'
It's just a small modification of script from here, with adding new line to start next console command on the new line, removed commas at the end of each line and listing only my pods, without service pods (e.g. --all-namespaces option is removed).
There are enough answers here but sometimes you want to see a deployment object pods' containers and initContainers. To do that;
1- Retrieve the deployment name
kubectl get deployment
2- Retrieve containers' names
kubectl get deployment <deployment-name> -o jsonpath='{.spec.template.spec.containers[*].name}'
3- Retrieve initContainers' names
kubectl get deployment <deployment-name> -o jsonpath='{.spec.template.spec.initContainers[*].name}'
Easiest way to know the containers in a pod:
kubectl logs -c -n