I want to spin up a single installer pod with helm install that once running, will apply some logic and install other applications into my cluster using helm install.
I'm aware of the helm dependencies, but I want to run some business logic with the installations and I'd rather do it in the installer pod and on the host triggering the whole installation process.
I found suggestions on using the Kubernetes REST API when inside a pod, but helm requires kubectl installed and configured.
Any ideas?
It seems this was a lot easier than I thought...
On a simple pod running Debian, I just installed kubectl, and with the default service account's secret that's already mounted, the kubectl was already configured to the cluster's API.
Note that the configured default namespace is the one that my installer pod is deployed to.
Verified with
$ kubectl cluster-info
$ kubectl get ns
I then installed helm, which was already using the kubectl to access the cluster for installing tiller.
Verified with
$ helm version
$ helm init
I installed a test chart
$ helm install --name my-release stable/wordpress
It works!!
I hope this helps
You could add kubectl to your installer pod.
"In cluster" credentials could be provided via service account in "default-token" secret: https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/
Related
I'm trying to install telepresence into a EKS cluster that has PodSecurityPolicy's. I've gotten the traffic manager installed by running helm on the traffic manager chart:
helm install traffic-manager -n ambassador datawire/telepresence --create-namespace
After that I modify the traffic-manager-ambassador clusterRole to use one of the cluster PodSecurityPolicy's. Installation of the traffic manager eventually succeeds after I do this. However the installation of the uninstall-agent job fails:
Error creating: pods "uninstall-agents-" is forbidden: PodSecurityPolicy: unable to admit pod: []
My question is - what role or clusterRole do I have to modify to allow helm to uninstall telepresence? Or how do I figure out what service account is being used to try and install the pod so I can give it access to a pod security policy?
I made some fixes at https://github.com/ddl-pjohnson/telepresence/pull/1/files to make it easier to add additional rules and to run the helm hook as the correct user.
I have an application that is deployed on kubernetes cluster. Accessing this application using rancher namespace. By specifying this namespace I am getting "get pods", and all information.
Now, this application I want to control from the helm. what do I need to do?
I have installed helm where my kubectl installation is there.
If you want to "control" applications on Kubernetes cluster with Helm, you should start with helm charts. You can create some if one is not already available. Once you have chart(s), you can target the Kubernetes cluster with the cluster's KUBECONFIG file.
If I had a Helm chart like my-test-app and a Kubernetes cluster called my-dev-cluster.
With Helm I can:
deploy - install
helm install test1 my-test-app/ --kubeconfig ~/.kubeconfigs/my-dev-cluster.kubeconfig
update - upgrade
helm upgrade test1 my-test-app/ --kubeconfig ~/.kubeconfigs/my-dev-cluster.kubeconfig
remove - uninstall
helm uninstall test1 my-test-app/ --kubeconfig ~/.kubeconfigs/my-dev-cluster.kubeconfig
Where my-dev-cluster.kubeconfig is the kubeconfig file for my cluster in ~/.kubeconfigs directory. Or you can set the path using KUBECONFIG environment variable.
During Installation of Helm3 stable, i found Helm3 stable does not implement tiller deployment for fetching cluster details, it works as a Client utility only, my question is it, if it is not implementing tiller concept for fetching details, how does it connect with EKS.
I have already installed kubectl and it is running fine, is it something like this, helm client is dependent on kubectl service?
I performed following steps:
1.helm version
version.BuildInfo{Version:"v3.1.0", GitCommit:"b29d20baf09943e134c2fa5e1e1cab3bf93315fa", GitTreeState:"clean", GoVersion:"go1.13.7"}
2.kubectl create serviceaccount tiller --namespace kube-system
serviceaccount/tiller created
3.notepad rbac-config.yaml
4.kubectl apply -f rbac-config.yaml
clusterrolebinding.rbac.authorization.k8s.io/tiller-role-binding created
5.helm init --service-account tiller
Error: unknown flag: --service-account
I know steps 2,3,4 are not required in Helm3, but curious to know how helm3 interacts as a client service with EKS cluster.
Just like kubectl, helm also uses kubeconfig to communicate with the cluster.
So, both kubectl and helm depend on the cluster's config file rather depending on each other.
I have a Kubernetes cluster with 1 master node and 2 worker node. And I have another machine where I installed Helm. Actually I am trying to create Kubernetes resources using Helm chart and trying to deploy into remote Kubernetes cluster.
When I am reading about helm install command, I found that we need to use helm and kubectl command for deploying.
My confusion in here is that, when we using helm install, the created chart will deploy on Kubernetes and we can push it into chart repo also. So for deploying we are using Helm. But why we are using kubectl command with Helm?
Helm 3: No Tiller. Helm install just deploys stuff using kubectl underneath. So to use helm, you also need a configured kubectl.
Helm 2:
Helm/Tiller are client/server, helm needs to connect to tiller to initiate the deployment. Because tiller is not publicly exposed, helm uses kubectl underneath to open a tunnel to tiller. See here: https://github.com/helm/helm/issues/3745#issuecomment-376405184
So to use helm, you also need a configured kubectl. More detailed: https://helm.sh/docs/using_helm/
Chart Repo: is a different concept (same for helm2 / helm3), it's not mandatory to use. They are like artifact storage, for example in quay.io application registry you can audit who pushed and who used a chart. More detailed: https://github.com/helm/helm/blob/master/docs/chart_repository.md. You always can bypass repo and install from src like: helm install /path/to/chart/src
I'm working on kubernetes. Now I tried Digital Ocean's kubernetes which is very easy to install and access, but how can I install metric-server in it? how can I auto scale in kubernetes by DO?
Please reply as soon as possible.
The Metrics Server can be installed to your cluster with Helm:
https://github.com/helm/charts/tree/master/stable/metrics-server
helm init
helm upgrade --install metrics-server --namespace=kube-system stable/metrics-server
with RBAC enabled, see the more comprehensive instructions for installing Helm into your cluster:
https://github.com/helm/helm/blob/master/docs/rbac.md
If you wish to deploy without Helm, the manifests are available from the GitHub repository:
https://github.com/kubernetes-incubator/metrics-server/tree/master/deploy/1.8%2B