I'm very curious how I should combine my own Helm chart with a set of contributed charts, i.e. the ones of BitNami.
So say I have my own chart that defines my backend application, how do I add a dependency to the contributed MySQL chart (instead of manually crafting it myself).
Another use case would be to add ArgoCD to my own custom chart. How do I do this in a declarative manner, without running the needed commands on the cluster manually?
I'm aware of the helm repo add and helm install for 3rd party charts, but these commands do not lend them well for CI/CD because they are not idempotent. I would like my chart to be declarative, so a single helm install also installs all listed dependencies. And the weird thing is that I cannot find anything about this topic online.
Would love your feedback!
Related
I have a few services running on a kubernetes cluster, and I use Helm Chart where I placed all my services. However, I was asked to transfer Helm Charts into Helmfile.
If I use
helmfile import myrepo/mychart
helmfile sync
Will it redeploy and substitute existing running pods or It will deploy just deploy additional services mentioned
Helm uses a packaging format called charts. A chart is a collection of files that describe a related set of Kubernetes resources. A single chart might be used to deploy something simple, like a memcached pod, or something complex, like a full web app stack with HTTP servers, databases, caches, and so on.
Helmfile is a declarative spec for deploying helm charts. It lets you...
Keep a directory of chart value files and maintain changes in version control.
Apply CI/CD to configuration changes.
Periodically sync to avoid skew in environments.
To avoid upgrades for each iteration of helm, the helmfile executable delegates to helm - as a result, helm must be installed.
Like #DavidMaze suggested, use helm diff command first to determine the changes and then use helm sync command for applying them.
I've been developing a prototype chart that depends on some custom resource definitions that are defined in one of the child charts.
To be more specific, I'm trying to create the resources defined in the strimzi-kafka-operator within my helm chart and would like the dependency to be explicitly installed first. I followed the helm documentation and added the following to my Chart.yaml
dependencies:
- name: strimzi-kafka-operator
version: 0.16.2
repository: https://strimzi.io/charts/
I ran:
$ helm dep up ./prototype-chart
$ helm install ./prototype-chart
> Error: unable to build Kubernetes objects from release manifest: unable to recognize "": no matches for kind "KafkaTopic" in version "kafka.strimzi.io/v1beta1"
which shows that it's trying to deploy my chart before my dependency. What is the correct way to install dependencies first and then my parent chart?
(For reference, here is the question I opened on GitHub directly with Strimzi where they informed me they aren't sure how to use their helm as a dependency:
https://github.com/strimzi/strimzi-kafka-operator/issues/2552
)
Regarding CRD's: the fact that Helm by default won't manage those1 is a feature, not a bug. It will still install them if not present; but it won't modify or delete existing CRD's. The previous version of Helm (v2) does, but (speaking from experience) that can get you into all sorts of trouble if you're not careful. Quoting from the link you referenced:
There is not support at this time for upgrading or deleting CRDs using Helm. This was an explicit decision after much community discussion due to the danger for unintentional data loss. [...] One of the distinct disadvantages of the crd-install method used in Helm 2 was the inability to properly validate charts due to changing API availability (a CRD is actually adding another available API to your Kubernetes cluster). If a chart installed a CRD, helm no longer had a valid set of API versions to work against. [...] With the new crds method of CRD installation, we now ensure that Helm has completely valid information about the current state of the cluster.
The idea here is that Helm should operate only at the level of release data (adding/removing deployments, storage, etc.); but with CRD's, you're actually modifying an extension to the Kubernetes API itself, potentially inadvertently breaking other releases that use the same definitions. Consider if you're on a team that has a "library" of CRDs shared between several charts, and you want to uninstall one — formerly, With v2, Helm would happily let you modify or even delete those at will, with no checks on if/how they were used in other releases. Changes to CRDs are changes to your control plane / core API, and should be treated as such — you're modifying global resources.
In short: with v3, Helm positions itself more as a "developer" tool to define, template, and manage releases; CRDs, however, are meant to be managed independently e.g. by a "cluster administrator". At the end of the day, it's a win for all sides, since developers can setup/teardown deployments at will, with confidence that it's not going to break functionality elsewhere... and whoever's on call won't have to deal with alerts if/when you accidentally delete/modify a CRD and break things in production :)
See also the extensive discussion here for more context behind this decision.
Hope this helps!
I need to install a helm chart with a key/value that is not present in one of the templates and I prefer not to edit the already existing templates.
In particular, I need to change resources.limits.cpu and resources.limits.memory in k8s-job-template.yaml but resources is not even mentioned in that file.
Is there a solution for this?
The only customizations it's possible to make for a Helm chart are those the chart author has written in; you can't make arbitrary additional changes to the YAML files.
(Kustomize allows merges of arbitrary YAML content and is built into recent kubectl, but it doesn't have some of the lifecycle or advanced templating features of Helm.)
For future reference, I found a solution to this.
Simply download the chart using the following command:
helm fetch <chart> --untar --destination /local/path/to/chart
Go to the folder /local/path/to/chart/<chartname> and make the desired changes.
After this, simply install the helm chart based on the locally edited chart:
helm install /local/path/to/chart/<chartname>
I'm using helm charts to create deploy micro services, by executing helm create it creates basic chart with deployment, services and ingress but I have few other configurations such as horizontal pod autoscaler, pod disruption budget.
what I do currently copy the yaml and change accordingly, but this takes lot of time and I don't see this as a (correct way/best practice) to do it.
helm create <chartname>
I want to know how you can create helm charts and have your extra configurations as well.
Bitnami's guide to creating your first helm chart describes helm create as "the best way to get started" and says that "if you already have definitions for your application, all you need to do is replace the generated YAML files for your own". The approach is also suggested in the official helm docs and the chart developer guide. So you are acting on best advice.
It would be cool if there were a wizard you could use to take existing kubernetes yaml files and make a helm chart from them. One tool like this that is currently available is chartify. It is listed on helm's related projects page (and I couldn't see any others that would be relevant).
You can try using Move2Kube. You will have to put all your yamls (if the source is kubernetes yamls) or other source artifacts in a directory (say src) and do move2kube translate -s src/.
In the wizard that comes up, you can choose helm instead of yamls and it will create a helm chart for you.
So I am using the helm chart stable/traefik to deploy a reverse proxy to my cluster. I need to customise it beyond what is possible with the variables I can set for the template.
I want to enable the dashboard service while not creating an ingress for it (I set up OpenVPN to access the traefik dashboard only via VPN).
Both dashboard-ingress.yaml and dashboard-service.yaml conditionally include the ingress or the respective service based on the same variable {{- if .Values.dashboard.enabled }}
From my experience I would fork the helm chart and push the customised version to my own repository.
Is there a way to add that customization but keep the original helm chart from the stable repository?
You don't necessarily have to push to your own repository as you could take the source code and include the chart in your own as source. For example, if you dig into the gitlab chart in their charts dependencies they've included multiple other charts as source their, not packaged .tgz files. That enables you to make changes in the chart within your own source (much as the gitlab guys have). You could get the source using helm fetch stable/traefik --untar
However, including the chart as source is still quite close to forking. If you want to upgrade to get fixes then you still have to reapply your changes. I believe your only other option is to raise the issue on the official chart repo. Perhaps for your case you could suggest to the maintainers that the ingress be included only when .Values.dashboard.enabled and a separate ingress condition is met.