feat: add go-mod-cache feature (#1)

panz3r · web-flow · commit fc24a8b4da00 · 2025-01-21T13:58:35.000+01:00
* feat: add `go-mod-cache` feature

* docs: update main README

* chore: update `test` GitHub Actions workflow

- add `go-mod-cache` to features matrix

* fix(go-mod-cache): update install script to work in all test scenarios
diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
@@ -13,6 +13,7 @@ jobs:
     strategy:
       matrix:
         features:
+          - go-mod-cache
           - color
           - hello
         baseImage:
@@ -34,6 +35,7 @@ jobs:
     strategy:
       matrix:
         features:
+          - go-mod-cache
           - color
           - hello
     steps:
diff --git a/README.md b/README.md
@@ -1,188 +1,14 @@
-# Dev Container Features: Self Authoring Template
+# Dev Container Features
 
-> This repo provides a starting point and example for creating your own custom [dev container Features](https://containers.dev/implementors/features/), hosted for free on GitHub Container Registry.  The example in this repository follows the [dev container Feature distribution specification](https://containers.dev/implementors/features-distribution/).  
->
-> To provide feedback to the specification, please leave a comment [on spec issue #70](https://github.com/devcontainers/spec/issues/70). For more broad feedback regarding dev container Features, please see [spec issue #61](https://github.com/devcontainers/spec/issues/61).
+This repo contains a collection of custom [Dev Container Features](https://containers.dev/implementors/features/), hosted for free on GitHub Container Registry.
 
-## Example Contents
+## Features
 
-This repository contains a _collection_ of two Features - `hello` and `color`. These Features serve as simple feature implementations.  Each sub-section below shows a sample `devcontainer.json` alongside example usage of the Feature.
+| Feature         | Description |  
+| --------------- | ----------- |
+|[`go-mod-cache`](src/go-mod-cache) | Mounts the Go Module cache (`GOMODCACHE`) to a Docker Volume to share between multiple Dev Containers. |
 
-### `hello`
 
-Running `hello` inside the built container will print the greeting provided to it via its `greeting` option.
+---
 
-```jsonc
-{
-    "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
-    "features": {
-        "ghcr.io/devcontainers/feature-starter/hello:1": {
-            "greeting": "Hello"
-        }
-    }
-}
-```
-
-```bash
-$ hello
-
-Hello, user.
-```
-
-### `color`
-
-Running `color` inside the built container will print your favorite color to standard out.
-
-```jsonc
-{
-    "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
-    "features": {
-        "ghcr.io/devcontainers/feature-starter/color:1": {
-            "favorite": "green"
-        }
-    }
-}
-```
-
-```bash
-$ color
-
-my favorite color is green
-```
-
-## Repo and Feature Structure
-
-Similar to the [`devcontainers/features`](https://github.com/devcontainers/features) repo, this repository has a `src` folder.  Each Feature has its own sub-folder, containing at least a `devcontainer-feature.json` and an entrypoint script `install.sh`. 
-
-```
-├── src
-│   ├── hello
-│   │   ├── devcontainer-feature.json
-│   │   └── install.sh
-│   ├── color
-│   │   ├── devcontainer-feature.json
-│   │   └── install.sh
-|   ├── ...
-│   │   ├── devcontainer-feature.json
-│   │   └── install.sh
-...
-```
-
-An [implementing tool](https://containers.dev/supporting#tools) will composite [the documented dev container properties](https://containers.dev/implementors/features/#devcontainer-feature-json-properties) from the feature's `devcontainer-feature.json` file, and execute in the `install.sh` entrypoint script in the container during build time.  Implementing tools are also free to process attributes under the `customizations` property as desired.
-
-### Options
-
-All available options for a Feature should be declared in the `devcontainer-feature.json`.  The syntax for the `options` property can be found in the [devcontainer Feature json properties reference](https://containers.dev/implementors/features/#devcontainer-feature-json-properties).
-
-For example, the `color` feature provides an enum of three possible options (`red`, `gold`, `green`).  If no option is provided in a user's `devcontainer.json`, the value is set to "red".
-
-```jsonc
-{
-    // ...
-    "options": {
-        "favorite": {
-            "type": "string",
-            "enum": [
-                "red",
-                "gold",
-                "green"
-            ],
-            "default": "red",
-            "description": "Choose your favorite color."
-        }
-    }
-}
-```
-
-Options are exported as Feature-scoped environment variables.  The option name is captialized and sanitized according to [option resolution](https://containers.dev/implementors/features/#option-resolution).
-
-```bash
-#!/bin/bash
-
-echo "Activating feature 'color'"
-echo "The provided favorite color is: ${FAVORITE}"
-
-...
-```
-
-## Distributing Features
-
-### Versioning
-
-Features are individually versioned by the `version` attribute in a Feature's `devcontainer-feature.json`.  Features are versioned according to the semver specification. More details can be found in [the dev container Feature specification](https://containers.dev/implementors/features/#versioning).
-
-### Publishing
-
-> NOTE: The Distribution spec can be [found here](https://containers.dev/implementors/features-distribution/).  
->
-> While any registry [implementing the OCI Distribution spec](https://github.com/opencontainers/distribution-spec) can be used, this template will leverage GHCR (GitHub Container Registry) as the backing registry.
-
-Features are meant to be easily sharable units of dev container configuration and installation code.  
-
-This repo contains a **GitHub Action** [workflow](.github/workflows/release.yaml) that will publish each Feature to GHCR. 
-
-*Allow GitHub Actions to create and approve pull requests* should be enabled in the repository's `Settings > Actions > General > Workflow permissions` for auto generation of `src/<feature>/README.md` per Feature (which merges any existing `src/<feature>/NOTES.md`).
-
-By default, each Feature will be prefixed with the `<owner/<repo>` namespace.  For example, the two Features in this repository can be referenced in a `devcontainer.json` with:
-
-```
-ghcr.io/devcontainers/feature-starter/color:1
-ghcr.io/devcontainers/feature-starter/hello:1
-```
-
-The provided GitHub Action will also publish a third "metadata" package with just the namespace, eg: `ghcr.io/devcontainers/feature-starter`.  This contains information useful for tools aiding in Feature discovery.
-
-'`devcontainers/feature-starter`' is known as the feature collection namespace.
-
-### Marking Feature Public
-
-Note that by default, GHCR packages are marked as `private`.  To stay within the free tier, Features need to be marked as `public`.
-
-This can be done by navigating to the Feature's "package settings" page in GHCR, and setting the visibility to 'public`.  The URL may look something like:
-
-```
-https://github.com/users/<owner>/packages/container/<repo>%2F<featureName>/settings
-```
-
-<img width="669" alt="image" src="https://user-images.githubusercontent.com/23246594/185244705-232cf86a-bd05-43cb-9c25-07b45b3f4b04.png">
-
-### Adding Features to the Index
-
-If you'd like your Features to appear in our [public index](https://containers.dev/features) so that other community members can find them, you can do the following:
-
-* Go to [github.com/devcontainers/devcontainers.github.io](https://github.com/devcontainers/devcontainers.github.io)
-     * This is the GitHub repo backing the [containers.dev](https://containers.dev/) spec site
-* Open a PR to modify the [collection-index.yml](https://github.com/devcontainers/devcontainers.github.io/blob/gh-pages/_data/collection-index.yml) file
-
-This index is from where [supporting tools](https://containers.dev/supporting) like [VS Code Dev Containers](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers) and [GitHub Codespaces](https://github.com/features/codespaces) surface Features for their dev container creation UI.
-
-#### Using private Features in Codespaces
-
-For any Features hosted in GHCR that are kept private, the `GITHUB_TOKEN` access token in your environment will need to have `package:read` and `contents:read` for the associated repository.
-
-Many implementing tools use a broadly scoped access token and will work automatically.  GitHub Codespaces uses repo-scoped tokens, and therefore you'll need to add the permissions in `devcontainer.json`
-
-An example `devcontainer.json` can be found below.
-
-```jsonc
-{
-    "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
-    "features": {
-     "ghcr.io/my-org/private-features/hello:1": {
-            "greeting": "Hello"
-        }
-    },
-    "customizations": {
-        "codespaces": {
-            "repositories": {
-                "my-org/private-features": {
-                    "permissions": {
-                        "packages": "read",
-                        "contents": "read"
-                    }
-                }
-            }
-        }
-    }
-}
-```
+Made with ✨ & ❤️ by [ForWarD Software](https://github.com/forwardsoftware) and [contributors](https://github.com/forwardsoftware/devcontainer-features/graphs/contributors)
diff --git a/src/go-mod-cache/README.md b/src/go-mod-cache/README.md
@@ -0,0 +1,25 @@
+
+# Go Mod Cache (go-mod-cache)
+
+Mounts the Go Module cache (`GOMODCACHE`) to a Docker Volume to share between multiple Dev Containers.
+
+## Example Usage
+
+```json
+"features": {
+    "ghcr.io/forwardsoftware/devcontainer-features/go-mod-cache:1": {
+    }
+}
+```
+
+## Options
+
+| Options Id | Description | Type | Default Value |
+|-----|-----|-----|-----|
+
+
+
+
+---
+
+_Note: This file was auto-generated from the [devcontainer-feature.json](https://github.com/devcontainers/feature-starter/blob/main/src/hello/devcontainer-feature.json).  Add additional notes to a `NOTES.md`._
diff --git a/src/go-mod-cache/devcontainer-feature.json b/src/go-mod-cache/devcontainer-feature.json
@@ -0,0 +1,18 @@
+{
+    "name": "Go Mod Cache",
+    "id": "go-mod-cache",
+    "version": "1.0.0",
+    "description": "Mounts the Go Module cache (`GOMODCACHE`) to a Docker Volume to share between multiple Dev Containers.",
+    "options": {},
+    "mounts": [
+        {
+            "source": "global-devcontainer-go-cache",
+            "target": "/mnt/go-cache",
+            "type": "volume"
+        }
+    ],
+    "installsAfter": [
+        "ghcr.io/devcontainers/features/common-utils",
+        "ghcr.io/devcontainers/features/go"
+    ]
+}
diff --git a/src/go-mod-cache/install.sh b/src/go-mod-cache/install.sh
@@ -0,0 +1,58 @@
+#!/bin/sh
+
+set -e
+
+echo "Activating feature 'go-mod-cache'"
+
+USERNAME=${USERNAME:-${_REMOTE_USER}}
+GOPATH=${GOPATH:-/go}
+
+setup_groups() {
+    if ! getent group golang > /dev/null; then
+        echo "Group 'golang' does not exist. Creating..."
+        groupadd golang
+    else
+        echo "Group 'golang' already exists. Skip creation..."
+    fi
+}
+
+create_dir() {
+    local target_dir=$1
+    local username=$2
+
+    if [ -d "$target_dir" ]; then
+        echo "Directory $target_dir already exists. Skip creation..."
+    else
+        echo "Create directory $target_dir..."
+        mkdir -p "$target_dir"
+    fi
+
+    if [ -z "$username" ]; then
+        echo "No username provided. Skip chown..."
+    else
+        echo "Change owner of $target_dir to $username..."
+        chown -R "$username:golang" "$target_dir"
+    fi
+}
+
+symlink_dirs() {
+    local local_dir=$1
+    local cache_dir=$2
+    local username=$3
+
+    # if the folder we want to symlink already exists, the ln -s command will create a folder inside the existing folder
+    if [ -e "$local_dir" ]; then
+        echo "Moving existing $local_dir folder to $local_dir-old"
+        mv "$local_dir" "$local_dir-old"
+    fi
+
+    echo "Symlink $local_dir to $cache_dir for $username..."
+    runuser -u "$username" -- ln -s "$cache_dir" "$local_dir"
+}
+
+setup_groups
+create_dir "/mnt/go-cache" "${USERNAME}"
+create_dir "$GOPATH" "${USERNAME}"
+symlink_dirs "$GOPATH/pkg" "/mnt/go-cache" "${USERNAME}"
+
+echo "Finished installing 'go-mod-cache'"
diff --git a/test/go-mod-cache/custom_user.sh b/test/go-mod-cache/custom_user.sh
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -e
+
+# tests installing feature with a custom user
+
+./test.sh
diff --git a/test/go-mod-cache/go_feature.sh b/test/go-mod-cache/go_feature.sh
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -e
+
+# tests installing feature when go is installed as feature
+
+./test.sh
diff --git a/test/go-mod-cache/scenarios.json b/test/go-mod-cache/scenarios.json
@@ -0,0 +1,35 @@
+{
+    "with_go": {
+        "image": "mcr.microsoft.com/devcontainers/go:1-1",
+        "features": {
+            "go-mod-cache": {}
+        }
+    },
+    "go_feature": {
+        "image": "mcr.microsoft.com/devcontainers/base",
+        "features": {
+            "ghcr.io/devcontainers/features/go:1": {},
+            "go-mod-cache": {}
+        }
+    },
+    "zsh_shell": {
+        "image": "mcr.microsoft.com/devcontainers/go:1-1",
+        "features": {
+            "ghcr.io/devcontainers/features/common-utils:2": {
+                "configureZshAsDefaultShell": true
+            },
+            "go-mod-cache": {}
+        }
+    },
+    "custom_user": {
+        "image": "mcr.microsoft.com/devcontainers/base",
+        "features": {
+            "ghcr.io/devcontainers/features/common-utils:2": {
+                "username": "golang"
+            },
+            "ghcr.io/devcontainers/features/go:1": {},
+            "go-mod-cache": {}
+        },
+        "remoteUser": "golang"
+    }
+}
diff --git a/test/go-mod-cache/test.sh b/test/go-mod-cache/test.sh
diff --git a/test/go-mod-cache/with_go.sh b/test/go-mod-cache/with_go.sh
diff --git a/test/go-mod-cache/zsh_shell.sh b/test/go-mod-cache/zsh_shell.sh
