The Chart Repository Guide
The Chart Repository Guide
This section explains how to create and work with Helm chart repositories. At a high level, a chart repository is a location where packaged charts can be stored and shared.
The official chart repository is maintained by the Kubernetes Charts, and we welcome participation. But Helm also makes it easy to create and run your own chart repository. This guide explains how to do so.
Create a chart repository
A chart repository is an HTTP server that houses an
index.yaml file and
optionally some packaged charts. When you’re ready to share your charts, the
preferred way to do so is by uploading them to a chart repository.
Note: For Helm 2.0.0, chart repositories do not have any intrinsic authentication. There is an issue tracking progress in GitHub.
Because a chart repository can be any HTTP server that can serve YAML and tar files and can answer GET requests, you have a plethora of options when it comes down to hosting your own chart repository. For example, you can use a Google Cloud Storage (GCS) bucket, Amazon S3 bucket, Github Pages, or even create your own web server.
The chart repository structure
A chart repository consists of packaged charts and a special file called
index.yaml which contains an index of all of the charts in the repository.
Frequently, the charts that
index.yaml describes are also hosted on the same
server, as are the provenance files.
For example, the layout of the repository
look like this:
charts/ | |- index.yaml | |- alpine-0.1.2.tgz | |- alpine-0.1.2.tgz.prov
In this case, the index file would contain information about one chart, the Alpine
chart, and provide the download URL
for that chart.
It is not required that a chart package be located on the same server as the
index.yaml file. However, doing so is often the easiest.
The index file
The index file is a yaml file called
contains some metadata about the package, including the contents of a
Chart.yaml file. A valid chart repository must have an index file. The
index file contains information about each chart in the chart repository. The
helm repo index command will generate an index file based on a given local
directory that contains packaged charts.
This is an example of an index file:
apiVersion: v1 entries: alpine: - created: 2016-10-06T16:23:20.499814565-06:00 description: Deploy a basic Alpine Linux pod digest: 99c76e403d752c84ead610644d4b1c2f2b453a74b921f422b9dcb8a7c8b559cd home: https://helm.sh/helm name: alpine sources: - https://github.com/helm/helm urls: - https://technosophos.github.io/tscharts/alpine-0.2.0.tgz version: 0.2.0 - created: 2016-10-06T16:23:20.499543808-06:00 description: Deploy a basic Alpine Linux pod digest: 515c58e5f79d8b2913a10cb400ebb6fa9c77fe813287afbacf1a0b897cd78727 home: https://helm.sh/helm name: alpine sources: - https://github.com/helm/helm urls: - https://technosophos.github.io/tscharts/alpine-0.1.0.tgz version: 0.1.0 nginx: - created: 2016-10-06T16:23:20.499543808-06:00 description: Create a basic nginx HTTP server digest: aaff4545f79d8b2913a10cb400ebb6fa9c77fe813287afbacf1a0b897cdffffff home: https://helm.sh/helm name: nginx sources: - https://github.com/helm/charts urls: - https://technosophos.github.io/tscharts/nginx-1.1.0.tgz version: 1.1.0 generated: 2016-10-06T16:23:20.499029981-06:00
A generated index and packages can be served from a basic webserver. You can test
things out locally with the
helm serve command, which starts a local server.
$ helm serve --repo-path ./charts Regenerating index. This may take a moment. Now serving you on 127.0.0.1:8879
The above starts a local webserver, serving the charts it finds in
serve command will automatically generate an
index.yaml file for you during
Hosting Chart Repositories
This part shows several ways to serve a chart repository.
Google Cloud Storage
The first step is to create your GCS bucket. We’ll call ours
Next, make your bucket public by editing the bucket permissions.
Insert this line item to make your bucket public:
Congratulations, now you have an empty GCS bucket ready to serve charts!
You may upload your chart repository using the Google Cloud Storage command line tool, or using the GCS web UI. This is the technique the official Kubernetes Charts repository hosts its charts, so you may want to take a peek at that project if you get stuck.
Note: A public GCS bucket can be accessed via simple HTTPS at this address
You can also set up chart repositories using JFrog Artifactory. Read more about chart repositories with JFrog Artifactory here
Github Pages example
In a similar way you can create charts repository using GitHub Pages.
GitHub allows you to serve static web pages in two different ways:
- By configuring a project to serve the contents of its
- By configuring a project to serve a particular branch
We’ll take the second approach, though the first is just as easy.
The first step will be to create your gh-pages branch. You can do that locally as.
$ git checkout -b gh-pages
Or via web browser using Branch button on your Github repository:
Next, you’ll want to make sure your gh-pages branch is set as Github Pages, click on your repo Settings and scroll down to Github pages section and set as per below:
By default Source usually gets set to gh-pages branch. If this is not set by default, then select it.
You can use a custom domain there if you wish so.
And check that Enforce HTTPS is ticked, so the HTTPS will be used when charts are served.
In such setup you can use master branch to store your charts code, and
gh-pages branch as charts repository, e.g.:
https://USERNAME.github.io/REPONAME. The demonstration TS Charts
repository is accessible at
Ordinary web servers
To configure an ordinary web server to serve Helm charts, you merely need to do the following:
- Put your index and charts in a directory that the server can serve
- Make sure the
index.yamlfile can be accessed with no authentication requirement
- Make sure
yamlfiles are served with the correct content type (
For example, if you want to serve your charts out of
$WEBROOT/charts, make sure
there is a
charts/ directory in your web root, and put the index file and
charts inside of that folder.
Managing Chart Repositories
Now that you have a chart repository, the last part of this guide explains how to maintain charts in that repository.
Store charts in your chart repository
Now that you have a chart repository, let’s upload a chart and an index file to
the repository. Charts in a chart repository must be packaged
helm package chart-name/) and versioned correctly (following
SemVer 2 guidelines).
These next steps compose an example workflow, but you are welcome to use whatever workflow you fancy for storing and updating charts in your chart repository.
Once you have a packaged chart ready, create a new directory, and move your packaged chart to that directory.
$ helm package docs/examples/alpine/ $ mkdir fantastic-charts $ mv alpine-0.1.0.tgz fantastic-charts/ $ helm repo index fantastic-charts --url https://fantastic-charts.storage.googleapis.com
The last command takes the path of the local directory that you just created and
the URL of your remote chart repository and composes an
index.yaml file inside the
given directory path.
Now you can upload the chart and the index file to your chart repository using a sync tool or manually. If you’re using Google Cloud Storage, check out this example workflow using the gsutil client. For GitHub, you can simply put the charts in the appropriate destination branch.
Add new charts to an existing repository
Each time you want to add a new chart to your repository, you must regenerate
the index. The
helm repo index command will completely rebuild the
file from scratch, including only the charts that it finds locally.
However, you can use the
--merge flag to incrementally add new charts to an
index.yaml file (a great option when working with a remote repository
like GCS). Run
helm repo index --help to learn more,
Make sure that you upload both the revised
index.yaml file and the chart. And
if you generated a provenance file, upload that too.
Share your charts with others
When you’re ready to share your charts, simply let someone know what the URL of your repository is.
From there, they will add the repository to their helm client via the
repo add [NAME] [URL] command with any name they would like to use to
reference the repository.
$ helm repo add fantastic-charts https://fantastic-charts.storage.googleapis.com $ helm repo list fantastic-charts https://fantastic-charts.storage.googleapis.com
If the charts are backed by HTTP basic authentication, you can also supply the username and password here:
$ helm repo add fantastic-charts https://fantastic-charts.storage.googleapis.com --username my-username --password my-password $ helm repo list fantastic-charts https://fantastic-charts.storage.googleapis.com
Note: A repository will not be added if it does not contain a valid
After that, your users will be able to search through your charts. After you’ve updated
the repository, they can use the
helm repo update command to get the latest
Under the hood, the
helm repo add and
helm repo update commands are
fetching the index.yaml file and storing them in the
$XDG_CACHE_HOME/helm/repository/cache/ directory. This is where the
function finds information about charts.