CI: Automate releases with a scheduled job

Introduce a new CI job in .gitlab-ci-release.yml to automate the
creation of project releases.

This single job, designed to run on a schedule, contains logic to:

  - create a final release (e.g. 2025.08) on the first Monday of an
    even-numbered month.
  - create a release candidate (e.g. 2025.07-rc1) on all other
    scheduled days.

This uses official release-cli to create both the git tag and the
corresponding GitLab Release entry automatically.

Signed-off-by: Simon Glass <sjg@chromium.org>

.gitlab-ci-release.yml

@@ -0,0 +1,48 @@
+# .gitlab-ci-release.yml
+
+# This single job handles the creation of both final releases and release candidates.
+# It determines which type of release to create based on the date.
+release:create:
+  stage: release
+  # We use the official release-cli image provided by GitLab.
+  image: registry.gitlab.com/gitlab-org/release-cli:latest
+  rules:
+    # This job only runs on scheduled pipelines that target the 'master' branch.
+    - if: '$CI_PIPELINE_SOURCE == "schedule" && $CI_COMMIT_REF_NAME == "master"'
+  script:
+    - |
+      echo "🚀 Checking release conditions for pipeline on branch '$CI_COMMIT_REF_NAME'..."
+      # Use %-m, %-u, %-d to avoid issues with zero-padding (e.g., '08' being an invalid octal number).
+      MONTH=$(date +%-m)
+      DAY_OF_WEEK=$(date +%-u) # 1=Monday, 7=Sunday
+      DAY_OF_MONTH=$(date +%-d)
+
+      # FINAL RELEASE: Occurs on the first Monday of an even-numbered month.
+      # 1. The month is even (e.g., February, April...).
+      # 2. The day of the week is Monday.
+      # 3. The day is within the first 7 days of the month.
+      if [ $((MONTH % 2)) -eq 0 ] && [ "$DAY_OF_WEEK" -eq 1 ] && [ "$DAY_OF_MONTH" -le 7 ]; then
+
+        # This is a Final Release
+        TAG_NAME=$(date +%Y.%m)
+        RELEASE_TITLE="Release $TAG_NAME"
+        echo "✅ Conditions met for a Final Release. Creating tag: $TAG_NAME"
+
+      else
+
+        # This is a Release Candidate (RC)
+        # RC index is calculated based on the day of the month:
+        # Days 1-14 -> rc1, Days 15-28 -> rc2, etc.
+        RC_INDEX=$(( (DAY_OF_MONTH - 1) / 14 + 1 ))
+        TAG_NAME="$(date +%Y.%m)-rc${RC_INDEX}"
+        RELEASE_TITLE="Release Candidate $TAG_NAME"
+        echo "📝 Conditions met for a Release Candidate. Creating tag: $TAG_NAME"
+
+      fi
+
+      echo "Executing release-cli to create the release..."
+      release-cli create \
+        --name "$RELEASE_TITLE" \
+        --tag-name "$TAG_NAME" \
+        --description "Automated release created by GitLab CI. Based on commit $CI_COMMIT_SHORT_SHA on the '$CI_COMMIT_REF_NAME' branch." \
+        --ref "$CI_COMMIT_SHA"

.gitlab-ci.yml

@@ -1,5 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0+
 
+include:
+  - local: '.gitlab-ci-release.yml'
+
 variables:
   DEFAULT_TAG: ""
   MIRROR_DOCKER: docker.io
@@ -24,6 +27,7 @@ stages:
   - test.py
   - sjg-lab
   - world build
+  - release
 
 .buildman_and_testpy_template: &buildman_and_testpy_dfn
   stage: test.py