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Installing Helm

There are two parts to Helm: The Helm client (helm) and the Helm server (Tiller). This guide shows how to install the client, and then proceeds to show two ways to install the server.

Installing the Helm Client

The Helm client can be installed either from source, or from pre-built binary releases.

From the Binary Releases

Every release of Helm provides binary releases for a variety of OSes. These binary versions can be manually downloaded and installed.

Download your desired version
Unpack it (tar -zxvf helm-v2.0.0-linux-amd64.tgz)
Find the helm binary in the unpacked directory, and move it to its desired destination (mv linux-amd64/helm /usr/local/bin/helm)

From there, you should be able to run the client: helm help.

From Homebrew (macOS)

Members of the Kubernetes community have contributed a Helm formula build to Homebrew. This formula is generally up to date.

brew install kubernetes-helm

(Note: There is also a formula for emacs-helm, which is a different project.)

From Script

Helm now has an installer script that will automatically grab the latest version of the Helm client and install it locally.

You can fetch that script, and then execute it locally. It's well documented so that you can read through it and understand what it is doing before you run it.

$ curl https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get > get_helm.sh
$ chmod 700 get_helm.sh
$ ./get_helm.sh

Yes, you can curl https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get | bash that if you want to live on the edge.

From Canary Builds

"Canary" builds are versions of the Helm software that are built from the latest master branch. They are not official releases, and may not be stable. However, they offer the opportunity to test the cutting edge features.

Canary Helm binaries are stored in the Kubernetes Helm GCS bucket. Here are links to the common builds:

From Source (Linux, macOS)

Building Helm from source is slightly more work, but is the best way to go if you want to test the latest (pre-release) Helm version.

You must have a working Go environment with glide and Mercurial installed.

$ cd $GOPATH
$ mkdir -p src/k8s.io
$ cd src/k8s.io
$ git clone https://github.com/kubernetes/helm.git
$ cd helm
$ make bootstrap build

The bootstrap target will attempt to install dependencies, rebuild the vendor/ tree, and validate configuration.

The build target will compile helm and place it in bin/helm. Tiller is also compiled, and is placed in bin/tiller.

Installing Tiller

Tiller, the server portion of Helm, typically runs inside of your Kubernetes cluster. But for development, it can also be run locally, and configured to talk to a remote Kubernetes cluster.

Easy In-Cluster Installation

The easiest way to install tiller into the cluster is simply to run helm init. This will validate that helm's local environment is set up correctly (and set it up if necessary). Then it will connect to whatever cluster kubectl connects to by default (kubectl config view). Once it connects, it will install tiller into the kube-system namespace.

After helm init, you should be able to run kubectl get pods --namespace kube-system and see Tiller running.

You can explicitly tell helm init to...

Install the canary build with the --canary-image flag
Install a particular image (version) with --tiller-image
Install to a particular cluster with --kube-context
Install into a particular namespace with --tiller-namespace

Once Tiller is installed, running helm version should show you both the client and server version. (If it shows only the client version, helm cannot yet connect to the server. Use kubectl to see if any tiller pods are running.)

Helm will look for Tiller in the kube-system namespace unless --tiller-namespace or TILLER_NAMESPACE is set.

Installing Tiller Canary Builds

Canary images are built from the master branch. They may not be stable, but they offer you the chance to test out the latest features.

The easiest way to install a canary image is to use helm init with the --canary-image flag:

$ helm init --canary-image

This will use the most recently built container image. You can always uninstall Tiller by deleting the Tiller deployment from the kube-system namespace using kubectl.

Running Tiller Locally

For development, it is sometimes easier to work on Tiller locally, and configure it to connect to a remote Kubernetes cluster.

The process of building Tiller is explained above.

Once tiller has been built, simply start it:

$ bin/tiller
Tiller running on :44134

When Tiller is running locally, it will attempt to connect to the Kubernetes cluster that is configured by kubectl. (Run kubectl config view to see which cluster that is.)

You must tell helm to connect to this new local Tiller host instead of connecting to the one in-cluster. There are two ways to do this. The first is to specify the --host option on the command line. The second is to set the $HELM_HOST environment variable.

$ export HELM_HOST=localhost:44134
$ helm version # Should connect to localhost.
Client: &version.Version{SemVer:"v2.0.0-alpha.4", GitCommit:"db...", GitTreeState:"dirty"}
Server: &version.Version{SemVer:"v2.0.0-alpha.4", GitCommit:"a5...", GitTreeState:"dirty"}

Importantly, even when running locally, Tiller will store release configuration in ConfigMaps inside of Kubernetes.

Upgrading Tiller

As of Helm 2.2.0, Tiller can be upgraded using helm init --upgrade.

For older versions of Helm, or for manual upgrades, you can use kubectl to modify the Tiller image:

$ export TILLER_TAG=v2.0.0-beta.1        # Or whatever version you want
$ kubectl --namespace=kube-system set image deployments/tiller-deploy tiller=gcr.io/kubernetes-helm/tiller:$TILLER_TAG
deployment "tiller-deploy" image updated

Setting TILLER_TAG=canary will get the latest snapshot of master.

Deleting or Reinstalling Tiller

Because Tiller stores its data in Kubernetes ConfigMaps, you can safely delete and re-install Tiller without worrying about losing any data. The recommended way of deleting Tiller is with kubectl delete deployment tiller-deploy --namespace kube-system, or more concisely helm reset.

Tiller can then be re-installed from the client with:

$ helm init

Advanced Usage

helm init provides additional flags for modifying Tiller's deployment manifest before it is installed.

Using `--node-selectors`

The --node-selectors flag allows us to specify the node labels required for scheduling the Tiller pod.

The example below will create the specified label under the nodeSelector property.

helm init --node-selectors "beta.kubernetes.io/os"="linux"

The installed deployment manifest will contain our node selector label.

...
spec:
  template:
    spec:
      nodeSelector:
        beta.kubernetes.io/os: linux
...

Using `--override`

--override allows you to specify properties of Tiller's deployment manifest. Unlike the --set command used elsewhere in Helm, helm init --override manipulates the specified properties of the final manifest (there is no "values" file). Therefore you may specify any valid value for any valid property in the deployment manifest.

Override annotation

In the example below we use --override to add the revision property and set its value to 1.

helm init --override metadata.annotations."deployment\.kubernetes\.io/revision"="1"

Output:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
...

Override affinity

In the example below we set properties for node affinity. Multiple --override commands may be combined to modify different properties of the same list item.

helm init --override "spec.template.spec.affinity.nodeAffinity.preferredDuringSchedulingIgnoredDuringExecution[0].weight"="1" --override "spec.template.spec.affinity.nodeAffinity.preferredDuringSchedulingIgnoredDuringExecution[0].preference.matchExpressions[0].key"="e2e-az-name"

The specified properties are combined into the "preferredDuringSchedulingIgnoredDuringExecution" property's first list item.

...
spec:
  strategy: {}
  template:
    ...
    spec:
      affinity:
        nodeAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
          - preference:
              matchExpressions:
              - key: e2e-az-name
                operator: ""
            weight: 1
...

Using `--output`

The --output flag allows us skip the installation of Tiller's deployment manifest and simply output the deployment manifest to stdout in either JSON or YAML format. The output may then be modified with tools like jq and installed manually with kubectl.

In the example below we execute helm init with the --output json flag.

helm init --output json

The Tiller installation is skipped and the manifest is output to stdout in JSON format.

"apiVersion": "extensions/v1beta1",
"kind": "Deployment",
"metadata": {
    "creationTimestamp": null,
    "labels": {
        "app": "helm",
        "name": "tiller"
    },
    "name": "tiller-deploy",
    "namespace": "kube-system"
},
...

Storage backends

By default, tiller stores release information in ConfigMaps in the namespace where it is running. As of Helm 2.7.0, there is now a beta storage backend that uses Secrets for storing release information. This was added for additional security in protecting charts in conjunction with the release of Secret encryption in Kubernetes.

To enable the secrets backend, you'll need to init Tiller with the following options:

helm init --override 'spec.template.spec.containers[0].command'='{/tiller,--storage=secret}'

Currently, if you want to switch from the default backend to the secrets backend, you'll have to do the migration for this on your own. When this backend graduates from beta, there will be a more official path of migration

Conclusion

In most cases, installation is as simple as getting a pre-built helm binary and running helm init. This document covers additional cases for those who want to do more sophisticated things with Helm.

Once you have the Helm Client and Tiller successfully installed, you can move on to using Helm to manage charts.

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