[eclipse-wakaamaGH-585] ci: Add initial gitlint usage

This is a fairly default configuration, which, among other stuff,
checks for the subject line being 72 or less characters as required by
the Eclipse project handbook.

In addition, it checks for the Signed-off-by tag. This simplifies to
detect missing signatures even before creating a PR when being executed
locally.

Please note:
 - gitlint 0.15.1 is required to detect the tags created by Git.
 - Using the gitlint-ignore tag in a commit message allows to suppress
   gitlint findings for a specific commit.

Signed-off-by: Reto Schneider <code@reto-schneider.ch>

.github/workflows/compliance.yaml

@@ -0,0 +1,22 @@
+name: Compliance
+
+on: pull_request
+
+jobs:
+  check-gitlint:
+    name: Run gitlint
+    runs-on: ubuntu-20.04
+
+    steps:
+    - name: Checkout code including full history
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+
+    - name: Install gitlint
+      run: |
+        pip3 install gitlint
+
+    - name: Check commits with checkpatch
+      run: |
+        tools/ci/run_ci.sh --branch-source origin/${{ github.head_ref }} --branch-target origin/${{ github.base_ref }} --run-gitlint

.gitlint

@@ -0,0 +1,2 @@
+[general]
+contrib=contrib-body-requires-signed-off-by,CC1

tools/ci/run_ci.sh

@@ -20,6 +20,8 @@ readonly REPO_ROOT_DIR="${PWD}"
 readonly SCRIPT_NAME="$(basename "$0")"
 
 CMAKE_ARGS="-DCMAKE_BUILD_TYPE=RelWithDebInfo"
+OPT_BRANCH_SOURCE=
+OPT_BRANCH_TARGET=master
 OPT_C_EXTENSIONS=""
 OPT_C_STANDARD=""
 OPT_SANITIZER=""
@@ -30,13 +32,18 @@ OPT_VERBOSE=0
 OPT_WRAPPER_CMD=""
 RUN_BUILD=0
 RUN_CLEAN=0
+RUN_GITLINT=0
 RUN_TESTS=0
 
 HELP_MSG="usage: ${SCRIPT_NAME} <OPTIONS>...
 Runs build and test steps in CI.
 Select steps to execute with --run- options
 
 Options:
+  --branch-source BRANCH    Source branch for MRs
+                            (default: current branch)
+  --branch-target BRANCH    Target branch for MRs
+                            (default: $OPT_BRANCH_TARGET)
   --c-extensions ENABLE     Whether to allow compiler extensions. Defaults to
                             ON.
                             (ENABLE: ON or OFF)
@@ -56,6 +63,7 @@ Options:
   -h, --help                Display this help and exit
 
 Available steps (executed by --all):
+  --run-gitlint            Check git commits with gitlint
   --run-clean              Remove all build artifacts
   --run-build              Build all targets
   --run-tests              Build and execute tests
@@ -72,6 +80,12 @@ function run_clean() {
   rm -rf build-wakaama
 }
 
+function run_gitlint() {
+    commits="${OPT_BRANCH_TARGET}...${OPT_BRANCH_SOURCE}"
+
+    gitlint --commits "${commits}"
+}
+
 function run_build() {
   # Existing directory needed by SonarQube build-wrapper
   mkdir -p build-wakaama
@@ -135,11 +149,14 @@ fi
 
 if ! PARSED_OPTS=$(getopt -o vah \
                           -l all \
+                          -l branch-source: \
+                          -l branch-target: \
                           -l c-extensions: \
                           -l c-standard: \
                           -l help \
                           -l run-build \
                           -l run-clean \
+                          -l run-gitlint \
                           -l run-tests \
                           -l sanitizer: \
                           -l scan-build: \
@@ -155,6 +172,14 @@ eval set -- "${PARSED_OPTS}"
 
 while true; do
   case "$1" in
+    --branch-source)
+      OPT_BRANCH_SOURCE=$2
+      shift 2
+      ;;
+    --branch-target)
+      OPT_BRANCH_TARGET=$2
+      shift 2
+      ;;
     --c-extensions)
       OPT_C_EXTENSIONS=$2
       shift 2
@@ -171,6 +196,10 @@ while true; do
       RUN_BUILD=1
       shift 1
       ;;
+    --run-gitlint)
+      RUN_GITLINT=1
+      shift
+      ;;
     --run-tests)
       RUN_TESTS=1
       shift
@@ -205,6 +234,7 @@ while true; do
       ;;
     -a|--all)
       RUN_CLEAN=1
+      RUN_GITLINT=1
       RUN_BUILD=1
       RUN_TESTS=1
       shift
@@ -262,6 +292,10 @@ fi
 
 # Run Steps
 
+if [[ $RUN_GITLINT == 1 ]]; then
+    run_gitlint
+fi
+
 if [ "${RUN_CLEAN}" -eq 1 ]; then
   run_clean
 fi