Is there a way to find the history of commands applied to the kubernetes cluster by kubectl?
For example, I want to know the last applied command was
kubectl apply -f x.yaml
or
kubectl apply -f y.yaml
You can use kubectl apply view-last-applied command to find the last applied configuration:
➜ ~ kubectl apply view-last-applied --help
View the latest last-applied-configuration annotations by type/name or file.
The default output will be printed to stdout in YAML format. One can use -o option to change output format.
Examples:
# View the last-applied-configuration annotations by type/name in YAML.
kubectl apply view-last-applied deployment/nginx
# View the last-applied-configuration annotations by file in JSON
kubectl apply view-last-applied -f deploy.yaml -o json
[...]
To get the full history from the beginning of a cluster creation you should use audit logs as already mentioned in comments by #Jonas.
additionally, if you adopt gitops you could have all your cluster state under version control. It will allow you to trace back all the changes made to your cluster.
Related
I am looking to apply existing annotations on a Kubernetes resource to the underlying YAML configuration files. For example, this command will successfully find all pods with a label of "app=helloworld" or "app=testapp" and annotate them with "xyz=test_anno":
kubectl annotate pods -l 'app in (helloworld, testapp)' xyz=test_anno
However, this only applies the annotations to the running pods and doesn't change the YAML files. How do I force those changes to the YAML files so they're permanent, either after the fact or as part of kubectl annotate to start with?
You could use the kubectl patch command with a little tricks
kubectl patch $(k get po -l 'app in (helloworld, testapp)') -p '{"metadata":{"annotations":{"xyz":"test_anno"}}}'
How to find the location of a kubernetes object's definition file.
I know the name of a kubernetes deployment and want to make some changes directly to its definition file instead of using 'kubernetes edit deployment '
The object definitions are stored internally in Kubernetes in replicated storage that's not directly accessible. If you do change an object definition, you would still need to trigger the rest of the Kubernetes update sequence when an object changes.
Typical practice is to keep the Kubernetes YAML files in source control. You can then edit these locally, and use kubectl apply -f to send them to the cluster. If you don't have them then you can run commands like kubectl get deployment depl-name -o yaml to get them out, and then check in the results to your source control repository.
If you really want to edit YAML definitions in an imperative, non-reproducible way, kubectl edit is the most direct thing you can do.
You could execute kubectl get deployment <deployment-name> -o yaml to get the deployment definition in a yaml format (or -o json to get in a json format), save that to a file, edit the file and apply the changes.
In a step-by-step guide would be:
Run kubectl get deployment deployment-name -o yaml > deployment-name.yaml
Edit and save the deployment-name.yaml using the editor of your preference
Run kubectl apply -f deployment-name.yaml to apply the changes
It's all stored in etcd
Nodes
Namespaces
ServiceAccounts
Roles and RoleBindings, ClusterRoles / ClusterRoleBindings
ConfigMaps
Secrets
Workloads: Deployments, DaemonSets, Pods, …
Cluster’s certificates
The resources within each apiVersion
The events that bring the cluster in the current state
Take a look at this blog post
I have followed the getting started instructions here: https://linkerd.io/2/getting-started/
Please see the command below:
kubectl kustomize kustomize/deployment | \
linkerd inject - | \
kubectl apply -f -
emojivoto is now installed an accessible as I expected.
How can I remove emojivoto? This appears to work:
kubectl delete -f https://run.linkerd.io/emojivoto.yml
However, is it possible to do this without using an online resource?
This is of course possible: The mentioned yaml consists of multiple object definitions.
For example namespaces and service accounts.
Each of them can be deleted using kubectl delete <type> <name>.
Since all objects are created in the namespace emojivoto it is possible to remove everything by just removing the namespace: kubectl delete namespace emojivoto.
The other option is to save the yaml file locally and use kubectl delete -f <file> instead.
I'd like to diff a Kubernetes YAML template against the actual deployed ressources. This should be possible using kubectl diff. However, on my Kubernetes cluster in Azure, I get the following error:
Error from server (InternalError): Internal error occurred: admission webhook "aks-webhook-admission-controller.azmk8s.io" does not support dry run
Is there something I can enable on AKS to let this work or is there some other way of achieving the diff?
As a workaround you can use standard GNU/Linux diff command in the following way:
diff -uN <(kubectl get pods nginx-pod -o yaml) example_pod.yaml
I know this is not a solution but just workaround but I think it still can be considered as full-fledged replacement tool.
Thanks, but that doesn't work for me, because it's not just one pod
I'm interested in, it's a whole Helm release with deployment,
services, jobs, etc. – dploeger
But anyway you won't compare everything at once, will you ?
You can use it for any resource you like, not only for Pods. Just substitute Pod by any other resource you like.
Anyway, under the hood kubectl diff uses diff command
In kubectl diff --help you can read:
KUBECTL_EXTERNAL_DIFF environment variable can be used to select your
own diff command. By default, the "diff" command available in your
path will be run with "-u" (unified diff) and "-N" (treat absent files
as empty) options.
The real problem in your case is that you cannot use for some reason --dry-run on your AKS Cluster, which is question to AKS users/experts. Maybe it can be enabled somehow but unfortunately I have no idea how.
Basically kubectl diff compares already deployed resource, which we can get by:
kubectl get resource-type resource-name -o yaml
with the result of:
kubectl apply -f nginx.yaml --dry-run --output yaml
and not with actual content of your yaml file (simple cat nginx.yaml would be ok for that purpose).
You can additionally use:
kubectl get all -l "app.kubernetes.io/instance=<helm_release_name>" -o yaml
to get yamls of all resources belonging to specific helm release.
As you can read in man diff it has following options:
--from-file=FILE1
compare FILE1 to all operands; FILE1 can be a directory
--to-file=FILE2
compare all operands to FILE2; FILE2 can be a directory
so we are not limited to comparing single files but also files located in specific directory. Only we can't use these two options together.
So the full diff command for comparing all resources belonging to specific helm release currently deployed on our kubernetes cluster with yaml files from a specific directory may look like this:
diff -uN <(kubectl get all -l "app.kubernetes.io/instance=<helm_release_name>" -o yaml) --to-file=directory_containing_yamls/
kubectl supports --server-dry-run so that modifications are not persisted but changes from admission controllers etc. are applied. The default output looks something like the following:
$ kubectl apply --server-dry-run -f deployment.yaml
deployment.apps/nginx-deployment created (server dry run)
However, adding -v=8 shows me the response body with the actual JSON content that will be persisted to etcd. Is there any way to ask kubectl to print that in a nicer format without some crazy grepping etc.?
You can get the appropriate Json by using following command:
kubectl apply --server-dry-run - f deployment.yaml -o json
You can also use kubectl diff -f deployment.yaml to see what changed.