# Tailscale GitHub Action

This GitHub Action connects to your [Tailscale network](https://tailscale.com)
by adding a step to your workflow.

```yaml
- name: Tailscale
  uses: tailscale/github-action@v3
  with:
    oauth-client-id: ${{ secrets.TS_OAUTH_CLIENT_ID }}
    oauth-secret: ${{ secrets.TS_OAUTH_SECRET }}
    tags: tag:ci
```

Subsequent steps in the Action can then access nodes in your Tailnet.

oauth-client-id and oauth-secret are an [OAuth client](https://tailscale.com/s/oauth-clients/)
for the tailnet to be accessed. We recommend storing these as
[GitHub Encrypted Secrets.](https://docs.github.com/en/actions/security-guides/encrypted-secrets)
OAuth clients used for this purpose must have the
[`auth_keys` scope.](https://tailscale.com/kb/1215/oauth-clients#scopes)

tags is a comma-separated list of one or more [ACL Tags](https://tailscale.com/kb/1068/acl-tags/)
for the node. At least one tag is required: an OAuth client is not associated
with any of the Users on the tailnet, it has to Tag its nodes.

Nodes created by this Action are [marked as Ephemeral](https://tailscale.com/s/ephemeral-nodes) to
be automatically removed by the coordination server a short time after they
finish their run. The nodes are also [marked Preapproved](https://tailscale.com/kb/1085/auth-keys/)
on tailnets which use [Device Approval](https://tailscale.com/kb/1099/device-approval/)

## Eventual consistency

Propagating information about new peers - such as the node created by this action - across your tailnet
is an eventually consistent process, and brief delays are expected. Until the GitHub workflow node 
becomes visible, other peers will not accept connections. It is best to verify connectivity to the 
intended nodes before executing steps that rely on them.

You can do this by adding a list of targets to the action configuration:

```yaml
- name: Tailscale
  uses: tailscale/github-action@v3
  with:
    targets: 100.x.y.z,my-machine.my-tailnet.ts.net
```

or with the [tailscale ping](https://tailscale.com/kb/1080/cli#ping) command if you do not know the targets at the time of installing Tailscale in the workflow:

```bash
tailscale ping my-target.my-tailnet.ts.net
```

## Tailnet Lock

If you are using this Action in a [Tailnet
Lock](https://tailscale.com/kb/1226/tailnet-lock) enabled network, you need to:

* Authenticate using an ephemeral reusable [pre-signed auth key](
  https://tailscale.com/kb/1226/tailnet-lock#add-a-node-using-a-pre-signed-auth-key)
  rather than an OAuth client.
* Specify a [state directory](
  https://tailscale.com/kb/1278/tailscaled#flags-to-tailscaled) for the
  client to store the Tailnet Key Authority data in.

```yaml
- name: Tailscale
  uses: tailscale/github-action@v3
  with:
    authkey: tskey-auth-...
    statedir: /tmp/tailscale-state/
```

## Defining Tailscale version

Which Tailscale version to use can be set like this:

```yaml
- name: Tailscale
  uses: tailscale/github-action@v3
  with:
    oauth-client-id: ${{ secrets.TS_OAUTH_CLIENT_ID }}
    oauth-secret: ${{ secrets.TS_OAUTH_SECRET }}
    tags: tag:ci
    version: 1.52.0
```

If you'd like to specify the latest version, simply set the version as `latest`

```yaml
- name: Tailscale
  uses: tailscale/github-action@v3
  with:
    oauth-client-id: ${{ secrets.TS_OAUTH_CLIENT_ID }}
    oauth-secret: ${{ secrets.TS_OAUTH_SECRET }}
    tags: tag:ci
    version: latest
```

You can find the latest Tailscale stable version number at
https://pkgs.tailscale.com/stable/#static.


## Cache Tailscale binaries

Caching can reduce download times and download failures on runners with slower network connectivity. Although caching is not enabled by default, it is generally recommended.

You can opt in to caching Tailscale binaries by passing `'true'` to the `use-cache` input:

```yaml
- name: Tailscale
  uses: tailscale/github-action@v3
  with:
    oauth-client-id: ${{ secrets.TS_OAUTH_CLIENT_ID }}
    oauth-secret: ${{ secrets.TS_OAUTH_SECRET }}
    use-cache: 'true'
```