Is it possible to specify the Pod creation time as part of the k8s Pod Name?
Scenario:
I have many pods with the same name prefix (and uniquely generated tail-end of the name) and these are all names of log groups.
I wish to distinguish between log groups by creation time.
Unfortunately AWS CloudWatch Logs console does not sort by log group creation time.
No, not with a deployment at least, a stateful set would work but you should really be using labels here.
Related
is there a way to pull out the username who was the last one that updated a pod in a namespace?
I have already tried the below command but non of them get me the user name
helm get values *myservice*
kubectl get pod *mypod*
If you are the cluster-admin, then you can check the kubernetes audit logs and determine the activities done in any particular namespace.
You can find more about auditing here.
Problem:
I want every pod created in my cluster to hold\point the same data
e.g. let's say I want all of them to have an env vars like "OWNER=MYNAME".
there are multiple users in my cluster and I don't want them to start changing their YAMLs and manually assign OWNER:MYNAME to env.
Is there a way to have all current/future pods to be assigned automatically with a predefined value or mount a configmap so that the same information will be available in every single pod?
can this be done on the cluster level? namespace level?
I want it to be transparent to the user, meaning a user would apply whatever pod to the cluster, and the info could be available to him without even asking.
Thanks, everyone!
Pod Preset might help you here to partially achieve what you need. Pod Preset resource allows injecting additional runtime requirements into a Pod at creation time. You use label selectors to specify the Pods to which a given PodPreset applies.
Check this to know how pod preset works.
First you need to enable pod preset in your cluster.
You can use Pod Preset to inject env variables or volumes in your pod.
You can also inject configmap in your pod.
Make use of some common label for all the pods which you want to have common config, use this common label in your pod preset resource.
Unfortunately there are plans to remove pod presets altogether in coming releases, but I guess you can still use it with current releases. Although there are other implementations similar to pod presets, which you can try.
I have been struggling for some time to figure out how to accomplish the following:
I want to delete running pod on Azure Kubernetes Service cluster on scheduled basis, so that it respawns from deployment. This is required that application re-reads configuration files stored on shared storage and shared with other application.
I have found out that Kubernetes Jobs might be handy to accomplish this, but there is some but.
I cant figure how can I select corresponding pod related to my deployment as it adds random string to the deployment name, i.e
deployment-name-546fcbf44f-wckh4
Using selectors to get my pod doesnt succeed as there is not such operator like LIKE
kubectl get pods --field-selector metadata.name=deployment-name
No resources found
Looking at the official docs one way of doing this would be like so:
pods=$(kubectl get pods --selector=job-name=pi --output=jsonpath='{.items[*].metadata.name}')
echo $pods
you'd need to modify job-name to match your job name
https://kubernetes.io/docs/concepts/workloads/controllers/jobs-run-to-completion/#running-an-example-job
I am scraping the kubernetes metrics from prometheus and would need to extract the number of running pods.
I can see container_last_seen metrics but how should i get no of pods running. Can someone help on this?
If you need to get number of running pods, you can use a metric from the list of pods metrics https://github.com/kubernetes/kube-state-metrics/blob/master/docs/pod-metrics.md for that (To get the info purely on pods, it'd make sens to use pod-specific metrics).
For example if you need to get the number of pods per namespace, it'll be:
count(kube_pod_info{namespace="$namespace_name"}) by (namespace)
To get the number of all pods running on the cluster, then just do:
count(kube_pod_info)
Assuming you want to display that in Grafana according to your question tags, from this Kubernetes App Metrics dashboard for example:
count(count(container_memory_usage_bytes{container_name="$container", namespace="$namespace"}) by (pod_name))
You can just import the dashboard and play with the queries.
Depending on your configuration/deployment, you can adjust the variables container_name and namespace, grouping by (pod_name) and count'ing it does the trick. Some other label than pod_name can be used as long as it's shared between the pods you want to count.
If you want to see only the number of "deployed" pods in some namespace, you can use the solutions in previous answers.
My use case was to see the current running pods in some namespace and below is my solution:
'min_over_time(sum(group(kube_pod_container_status_ready{namespace="BC_NAME"}) by (pod,uid)) [5m:1m]) OR on() vector(0)'
Please replace BC_NAME with your namespace name.
The timespan provides you fine the data.
If no data found - no pod currently running it returns '0'
I am missing a feature in Kubernetes for horizontal scaling of "standalone" application (where you can assign one application to one user).
I would like to deploy several instances of Wordpress with kubernetes.
Each instance should have its own environment and data and assigned to one user.
At first I thought about Statefullset but the problem is that when you delete one pod, you have to delete it in reverse order or all in parallel ..
What if the 3rd user cancel the service and you want to delete only the third pod ?!
Deployments ? Then I have to create one unique Pod for each user with their own volume !? Where is kubernetes added value there ..
Do you have any other better idea ?
Regards,
I got an answer from a Slack user, StatefulSet should not be used in this case.
It's better to use one different deployment for each user (wordpres-).