feat(code-server): add code-server offline support

[michaelbrewer]

Changes

• Add "used_cached" which uses the cached copy of code-server if found, otherwise installs it from Github along with any extensions
• Add "offline" which uses the offline copy of code-server, and if not found returns an error
• Both modes applies any settings
• Both modes can not be used at the same time
• offline mode does not allow for extensions to be installed

Checklist

• Implement use_cached mode
• Implement offline mode
• Add more notes on offline support and reference other code documentation
• Add validation checks
• Add terraform unit tests
• Add bash unit tests
• Update docs to reference guides on air-gapped installs

Documentation examples

By default the module looks for code-server at /tmp/code-server but this can be changed with install_prefix.

Run an existing copy of code-server if found, otherwise download from GitHub:

module "code-server" {
  source     = "registry.coder.com/modules/code-server/coder"
  version    = "1.0.8"
  agent_id   = coder_agent.example.id
  use_cached = true
  extensions = ["dracula-theme.theme-dracula", "ms-azuretools.vscode-docker"]
}

Just run code-server in the background, don't fetch it from GitHub:

module "code-server" {
  source   = "registry.coder.com/modules/code-server/coder"
  version  = "1.0.8"
  agent_id = coder_agent.example.id
  offline  = true
}

Test cases

When offline is true and there is no copy of code-server is found

module "code-server" {
  source     = "registry.coder.com/modules/code-server/coder"
  version    = "1.0.8"
  agent_id   = coder_agent.example.id
  offline    = true
}

Then expect runtime error

Failed to find a copy of code-server

---

When use_cached is true and there is no copy of code-server is found

module "code-server" {
  source     = "registry.coder.com/modules/code-server/coder"
  version    = "1.0.8"
  agent_id   = coder_agent.example.id
  use_cached = true
  extensions = ["dracula-theme.theme-dracula", "ms-azuretools.vscode-docker"]
}

Then expect code-server to be installed

Installing code-server!
🥳 code-server has been installed in /home/local/.code-server
🧩 Installing extension dracula-theme.theme-dracula...
🧩 Installing extension ms-azuretools.vscode-docker...
👷 Running code-server in the background...
Check logs at /tmp/code-server.log!

---

When use_cached is true and offline is true

module "code-server" {
  source     = "registry.coder.com/modules/code-server/coder"
  version    = "1.0.8"
  agent_id   = coder_agent.example.id
  offline    = true
  use_cached = true
}

Then expect terraform validation error

Offline and Use Cached can not be used together

---

When offline is true and extensions are set

module "code-server" {
  source     = "registry.coder.com/modules/code-server/coder"
  version    = "1.0.8"
  agent_id   = coder_agent.example.id
  offline    = true
  extensions = ["dracula-theme.theme-dracula", "ms-azuretools.vscode-docker"]
}

Then expect terraform validation error

Offline mode does not allow extensions to be installed

---

When offline or use_cached is true and a copy of code-server is found then just run code-server in background

🥳 Found a copy of code-server
👷 Running code-server in the background...
Check logs at /tmp/code-server.log!

Notes on air-gapped installations

Some cases for running offline installs of code-server with extensions, is for performance reasons, or because the egress controls on the workspace is tightly controlled or is completely air-gapped.

There is also cases where the coder terraform provisioner is also air-gapped, for which you might have modules hosted on an air-gapped terraform enterprise, other methods are in the coder documentation. It might also be useful to link to the coder offline docs

related to #181

[michaelbrewer]

@matifali - this is a draft PR to add support for "offline" and maybe an option for download caching (so it only installed on first launch)

[code-asher]

Is this ready for review or should I wait until it comes out of draft?

[michaelbrewer]

Is this ready for review or should I wait until it comes out of draft?

It's a draft, as I want to see if it makes sense to add an option to use cached installed too

[michaelbrewer]

@code-asher it's ready to look at.

I did observe a weird behavior, when running from a cached version the "code-server" is available sooner, but the window is blank intialy. Also when it is open resizing the window does not repaint.

[code-asher]

Nice! I did not notice anything abnormal with the window when I ran with a cached copy.

[code-asher]

Looks great! I just have a question about a variable name in an error message.