virtuallypotato/content/posts/tailscale-golink-private-shortlinks-tailnet/index.md

---
title: "Tailscale golink: Private Shortlinks for your Tailnet" # Title of the blog post.
date: 2023-01-08T13:51:42-06:00 # Date of post creation.
# lastmod: 2023-01-08T13:51:42-06:00 # Date when last modified
description: "How to deploy Tailscale's golink service in a Docker container."
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series: Tips # Projects, Scripts, vRA8, K8s on vSphere
tags:
  - docker
  - vpn
  - tailscale
  - wireguard
  - containers
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---
I've shared in the past about how I use [custom search engines in Chrome](/abusing-chromes-custom-search-engines-for-fun-and-profit/) as quick web shortcuts. And I may have mentioned [my love for Tailscale](/tags/tailscale/) a time or two as well. Well I recently learned of a way to combine these two passions: [Tailscale golink](https://github.com/tailscale/golink). The [golink announcement poston the Tailscale blog](https://tailscale.com/blog/golink/) offers a great overview of the service:
> Using golink, you can create and share simple go/name links for commonly accessed websites, so that anyone in your network can access them no matter the device they’re on — without requiring browser extensions or fiddling with DNS settings. And because golink integrates with Tailscale, links are private to users in your tailnet without any separate user management, logins, or security policies. 

And these go links don't have to be simply static shortcuts; the system is able to leverage go templates to conditionally insert text into the target URL - similar to my custom search engine setup. The Tailscale blog also has some clever suggestions on how to use this capability. 

Sounds great - but how do you actually make golink available on your tailnet? Well, here's what I did to deploy the [golink Docker image](https://github.com/tailscale/golink/pkgs/container/golink) on a [Photon OS VM I set up running on my Quartz64 running ESXi-ARM](/esxi-arm-on-quartz64/#workload-creation).

## Tailnet prep
There are two things I'll need to do in the Tailscale admin portal before moving on.
### Create an ACL tag
I assign ACL tags to devices in my tailnet based on their location and/or purpose, and I'm then able to use those in a policy to restrict access between certain devices. To that end, I'm going to create a new `tag:golink` tag for this purpose. Creating a new tag in Tailscale is really just going to the [Access Controls page of the admin console](https://login.tailscale.com/admin/acls) and editing the policy to specify a `tagOwner` who is permitted to assign the tag:
```text {hl_lines=[11]}
	"groups":
		"group:admins": ["john@example.com"],
	},
	"tagOwners": {
		"tag:home":   ["group:admins"],
		"tag:cloud":  ["group:admins"],
		"tag:client": ["group:admins"],
		"tag:dns":    ["group:admins"],
		"tag:rsync":  ["group:admins"],
		"tag:funnel": ["group:admins"],
		"tag:golink": ["group:admins"],
	},
```

### Create an auth key
The second task is to create a new authentication key that the golink container can use to log in to Tailscale since I won't be running `tailscale` interactively. This can easily be done from the [Settings page](https://login.tailscale.com/admin/settings/keys). I'll go ahead and set the key to expire in 1 day (since I'm going to use it in just a moment), make sure that the Epheral option is _disabled_ (since I don't want the new node to lose its authorization once it disconnects), and associate it with my new `tag:golink` tag.

![Creating a new auth key](create_auth_key.png)

Applying that tag does two things for me: it makes it easy to manage access with the ACL policy file, and it automatically sets it so that the node's token won't automatically expire. Once it's auth'd and connected to my tailnet, it'll stay there.


## Docker setup
The [golink repo](https://github.com/tailscale/golink) offers this command for running the container:
```shell
docker run -it --rm ghcr.io/tailscale/golink:main
```

The doc also indicates that I can pass a Tailscale auth key to the golink service via the `TS_AUTHKEY` environment variable, and that all the configuration will be stored in `/home/nonroot` (which will be owned by uid/gid `65532`). I'll take this knowledge and use it to craft a `docker-compose.yml` to simplify container management.

```shell
mkdir -p golink/data
cd golink
chmod 65536:65563 data
vi docker-compose.yaml
```

```yaml
# golink docker-compose.yaml
version: '3'
services:
  golink:
    container_name: golink
    restart: unless-stopped
    image: ghcr.io/tailscale/golink:main
    environment:
      - TS_AUTHKEY: MY_TS_AUTHKEY
    volumes:
      - './data:/home/nonroot'
```

I'll need to create a new authentication key from the [Tailscale admin portal](https://login.tailscale.com/admin/settings/keys).