Add CI workflow to check for unapproved Go dependency licenses

A task and GitHub Actions workflow are provided here for checking the license types of Go project dependencies.

On every push and pull request that affects relevant files, the CI workflow will check:

- If the dependency licenses cache is up to date
- If any of the project's dependencies have an unapproved license type.

Approval can be based on:

- Universally allowed license type
- Individual dependency

.github/workflows/check-go-dependencies-task.yml

@@ -0,0 +1,140 @@
+# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/check-go-dependencies-task.md
+name: Check Go Dependencies
+
+env:
+  # See: https://github.com/actions/setup-go/tree/main#supported-version-syntax
+  GO_VERSION: "1.18.3"
+
+# See: https://docs.github.com/actions/using-workflows/events-that-trigger-workflows
+on:
+  create:
+  push:
+    paths:
+      - ".github/workflows/check-go-dependencies-task.ya?ml"
+      - ".licenses/**"
+      - ".licensed.json"
+      - ".licensed.ya?ml"
+      - "Taskfile.ya?ml"
+      - "**/.gitmodules"
+      - "**/go.mod"
+      - "**/go.sum"
+  pull_request:
+    paths:
+      - ".github/workflows/check-go-dependencies-task.ya?ml"
+      - ".licenses/**"
+      - ".licensed.json"
+      - ".licensed.ya?ml"
+      - "Taskfile.ya?ml"
+      - "**/.gitmodules"
+      - "**/go.mod"
+      - "**/go.sum"
+  schedule:
+    # Run periodically to catch breakage caused by external changes.
+    - cron: "0 8 * * WED"
+  workflow_dispatch:
+  repository_dispatch:
+
+jobs:
+  run-determination:
+    runs-on: ubuntu-latest
+    outputs:
+      result: ${{ steps.determination.outputs.result }}
+    steps:
+      - name: Determine if the rest of the workflow should run
+        id: determination
+        run: |
+          RELEASE_BRANCH_REGEX="refs/heads/[0-9]+.[0-9]+.x"
+          # The `create` event trigger doesn't support `branches` filters, so it's necessary to use Bash instead.
+          if [[
+            "${{ github.event_name }}" != "create" ||
+            "${{ github.ref }}" =~ $RELEASE_BRANCH_REGEX
+          ]]; then
+            # Run the other jobs.
+            RESULT="true"
+          else
+            # There is no need to run the other jobs.
+            RESULT="false"
+          fi
+
+          echo "::set-output name=result::$RESULT"
+
+  check-cache:
+    needs: run-determination
+    if: needs.run-determination.outputs.result == 'true'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+
+      - name: Install licensed
+        uses: jonabc/setup-licensed@v1
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Install Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Install Task
+        uses: arduino/setup-task@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Update dependencies license metadata cache
+        run: task --silent general:cache-dep-licenses
+
+      - name: Check for outdated cache
+        id: diff
+        run: |
+          git add .
+          if ! git diff --cached --color --exit-code; then
+            echo
+            echo "::error::Dependency license metadata out of sync. See: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/check-go-dependencies-task.md#metadata-cache"
+            exit 1
+          fi
+
+      # Some might find it convenient to have CI generate the cache rather than setting up for it locally
+      - name: Upload cache to workflow artifact
+        if: failure() && steps.diff.outcome == 'failure'
+        uses: actions/upload-artifact@v3
+        with:
+          if-no-files-found: error
+          name: dep-licenses-cache
+          path: .licenses/
+
+  check-deps:
+    needs: run-determination
+    if: needs.run-determination.outputs.result == 'true'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+
+      - name: Install licensed
+        uses: jonabc/setup-licensed@v1
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Install Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Install Task
+        uses: arduino/setup-task@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Check for dependencies with unapproved licenses
+        run: task --silent general:check-dep-licenses

.gitignore

@@ -1,4 +1,5 @@
 .old
 build.sh
-arduino-language-server*
+/arduino-language-server*
+!/arduino-language-server*/
 /node_modules/

.licensed.yml

@@ -0,0 +1,68 @@
+# See: https://github.com/github/licensed/blob/master/docs/configuration.md
+sources:
+  go: true
+
+apps:
+  - source_path: ./
+
+# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-dependencies/Apache-2.0/.licensed.yml
+allowed:
+  # Based on https://www.apache.org/legal/resolved.html#category-a
+  - apache-2.0
+  - apache-1.1
+  - php-3.01
+  # "MX4J License" - no SPDX ID
+  - bsd-2-clause
+  - bsd-2-clause-netbsd # Deprecated ID for `bsd-2-clause`
+  - bsd-2-clause-views
+  - bsd-2-clause-freebsd # Deprecated ID for `bsd-2-clause-views`
+  - bsd-3-clause
+  - bsd-3-clause-clear
+  # "DOM4J License" - no SPDX ID
+  - postgresql
+  # "Eclipse Distribution License 1.0" - no SPDX ID
+  - mit
+  - x11
+  - isc
+  - smlnj
+  - standardml-nj # Deprecated ID for `smlnj`
+  # "Cup Parser Generator" - no SPDX ID
+  - icu
+  - ncsa
+  - w3c
+  # "W3C Community Contributor License Agreement" - no SPDX ID
+  - xnet
+  - zlib
+  # "FSF autoconf license" - no SPDX ID
+  - afl-3.0
+  # "Service+Component+Architecture+Specifications" - no SPDX ID
+  # "OOXML XSD ECMA License"
+  - ms-pl
+  - cc-pddc
+  - psf-2.0
+  # "Python Imaging Library Software License"
+  - apafml
+  - bsl-1.0
+  - ogl-uk-3.0
+  - wtfpl
+  - unicode-tou
+  - zpl-2.0
+  # "ACE license" - no SPDX ID
+  - upl-1.0
+  # "Open Grid Forum License" - no SPDX ID
+  # 'Google "Additional IP Rights Grant (Patents)" file' - no SPDX ID
+  - unlicense
+  - hpnd
+  - mulanpsl-2.0
+  - cc0-1.0
+  # Based on individual license text
+  - lgpl-2.0-or-later
+  - lgpl-2.0+ # Deprecated ID for `lgpl-2.0-or-later`
+  - lgpl-2.1-only
+  - lgpl-2.1 # Deprecated ID for `lgpl-2.1-only`
+  - lgpl-2.1-or-later
+  - lgpl-2.1+ # Deprecated ID for `lgpl-2.1-or-later`
+  - lgpl-3.0-only
+  - lgpl-3.0 # Deprecated ID for `lgpl-3.0-only`
+  - lgpl-3.0-or-later
+  - lgpl-3.0+ # Deprecated ID for `lgpl-3.0-or-later`

README.md

@@ -6,6 +6,7 @@
 [![Check Go status](https://github.com/arduino/arduino-language-server/actions/workflows/check-go-task.yml/badge.svg)](https://github.com/arduino/arduino-language-server/actions/workflows/check-go-task.yml)
 [![Check Markdown status](https://github.com/arduino/arduino-language-server/actions/workflows/check-markdown-task.yml/badge.svg)](https://github.com/arduino/arduino-language-server/actions/workflows/check-markdown-task.yml)
 [![Check License status](https://github.com/arduino/arduino-language-server/actions/workflows/check-license.yml/badge.svg)](https://github.com/arduino/arduino-language-server/actions/workflows/check-license.yml)
+[![Check Go Dependencies status](https://github.com/arduino/arduino-language-server/actions/workflows/check-go-dependencies-task.yml/badge.svg)](https://github.com/arduino/arduino-language-server/actions/workflows/check-go-dependencies-task.yml)
 
 The **Arduino Language Server** is the tool that powers the autocompletion of the new [Arduino IDE 2][arduino-ide-repo]. It implements the standard [Language Server Protocol](https://microsoft.github.io/language-server-protocol/) so it can be used with other IDEs as well.