How do I get the External IP of a Kubernetes service as a raw value? - kubernetes

I am running an application with GKE. It works fine but I can not figure out how to get the external IP of the service in a machine readable format.
So i am searching a gcloud or kubectl command that gives me only the external IP or a url of the format http://192.168.0.2:80 so that I can cut out the IP.


You can use the jsonpath output type to get the data directly without needing the additional jq to process the json:
kubectl get services \
--namespace ingress-nginx \
nginx-ingress-controller \
--output jsonpath='{.status.loadBalancer.ingress[0].ip}'
NOTE
Be sure to replace the namespace and service name, respectively, with yours.


Maybe not GKE as my clusters are on AWS, but I assume logic will be similar. When you kubectl get svc you can select output format and it will show more then just the "normal" get. For me, with ELB based services to het LB hostname it's enough to run ie. kubectl -n kube-system get svc cluster-nginx-ingress-controller -o json | jq .status.loadBalancer.ingress.hostname


In my case 'kubectl get services' returns array of items, but not just one service.
So then such jsonpath works fine to me:
kubectl get services -l component=controller,app=nginx-ingress -o jsonpath="{.items[0].status.loadBalancer.ingress[0].ip}"


...and yet another way... This will list all the "load-balancer" services
kubectl get services --all-namespaces -o json | jq -r '.items[] | { name: .metadata.name, ns: .metadata.namespace, ip: .status.loadBalancer?|.ingress[]?|.ip }'
Depending on the networkPlugin used by your cluster services/pods may be exposed directly on external-ip. But this will also find an Ingress controllers run in the cluster.


To get the external-ip on GCP i can use:
kubectl get services --namespace=<your-namespace> -o jsonpath="{.items[0].status.loadBalancer.ingress[0].ip}"


The answers above do not provide the output the user asked. The correct command would be:
kubectl -n $namespace get svc $ingressServiceName -o json | jq -r .status.loadBalancer.ingress[].hostname


All previous solutions don't work any more for me (on GCP).
To get the IP:
kubectl get ingress <YOUR_INGRESS_NAME> -o jsonpath="{.status.loadBalancer.ingress[0].ip}"
To get the host-name:
kubectl get ingress <YOUR_INGRESS_NAME> -o jsonpath="{.spec.rules[0].host}"


Type
minikube tunnel
or
kubectl cluster-info
You can get the public exposed IP of your relevant service.

Related

Find out all the pods that are using default service account

We have a k8s cluster with 10 workers. we run hundreds of pods in the cluster. we want to avoid running pods with default service account.
Need to find out the pods that are running with default service account. am able to find the number of pods using default service account with grep command but also need the pod name and the image it is using. Let us know your thoughts

In Case if you want to use just kubectl without jq :
needed to print both namespace and the pod name
kubectl get pods --all-namespaces -o jsonpath='{range .items[?(#.spec.serviceAccountName == "default")]}{.metadata.namespace} {.metadata.name}{"\n"}{end}' 2>/dev/null
i have added 2>/dev/null to avoid printing whole json template in case if no field was found

I used the below command to identify the pods from each namespace that is using default service account
kubectl get pods --all-namespaces -o json | jq '.items[] | select(.spec.serviceAccountName?=="default") | "\(.metadata.namespace) \(.metadata.name)"' | cut -d'"' -f2 | sort

if you are using k9s you can also :pod then e the pod to see which service account it is associated with

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 to access port forward services on gke

I'm new to gke/gcp and this is my first project.
I'm setting up istio using https://istio.io/docs/setup/kubernetes/quick-start-gke-dm/ tutorial.
I've exposed grafana as shown in the post using:
kubectl -n istio-system port-forward $(kubectl -n istio-system get pod -l app=grafana -o jsonpath='{.items[0].metadata.name}') 3000:3000 &
curl http://localhost:3000/dashboard/db/istio-dashboard
gives me http page on terminal, to access it from the browser I'm using master ip I get after executing kubectl cluster-info.
http://{master-ip}:3000/dashboard/db/istio-dashboard is not accessible.
How do I access services using port-forward on gke?

First grab the name of the Pod
$ kubectl get pod
and then use the port-forward command.
$ kubectl port-forward <pod-name> 3000:3000
It worked for me, I've found it from this nice website also explained on detail how to do it. Hope it can be useful.

What (exact) http page is returned by the curl command? Both of these docs [1]&[2] suggest using the url (with localhost) in the browser after setting up a tunnel to Grafana: http://localhost:3000/dashboard/db/istio-dashboard
Alternatively, have you tried with istio-ingressgateway IP address?
[1] https://github.com/GoogleCloudPlatform/gke-istio-telemetry-demo#view-grafana-ui
[2] https://istio.io/docs/setup/kubernetes/quick-start-gke-dm/#grafana

Kubernetes - Get value of a specific metadata when using describe command

When ruining kubectl describe service MyService command and can get the details of my kubernetes service as per below sample:
I am only interested to get the value of LoadBalancer Ingress metadata. Is there a way to retrieve this specific metadata using kubectl describe command?

I think it's better to use the get method and the go-template output :
kubectl get svc MyService -o go-template --template='{{range .status.loadBalancer.ingress}}{{.ip}}{{end}}'
Otherwise (but I don't recommend it), use bash tools like grep and cut
kubectl describe svc MyService | grep "LoadBalancer Ingress" | cut -d ':' -f2

How do you define "LoadBalancer Ingress metadata"? The IP address? If so, that information should appear under "IP:", right on top of LoadBalancer Ingress. But the LoadBalancer type service is cloud provider specific.
Do you actually have an IP address assigned to that specific load balancer?

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