ci: adding automated release creating

* taiki-e/create-gh-release-action#13
* https://docs.github.com/en/actions/using-jobs/assigning-permissions-to-jobs

.github/workflows/releasing.yml

@@ -0,0 +1,20 @@
+name: Releasing
+on:
+  push:
+    branches: [main]
+permissions:
+  contents: write
+jobs:
+  Releasing:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download Earthly v0.7.5.
+        run: "sudo /bin/sh -c 'wget https://github.com/earthly/earthly/releases/download/v0.7.5/earthly-linux-amd64 -O /usr/local/bin/earthly && chmod +x /usr/local/bin/earthly'"
+      - name: Checkout code.
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      - name: Releasing.
+        run: earthly --ci --secret GH_TOKEN +releasing
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }} # This token is provided by GitHub Actions.

Earthfile

@@ -175,3 +175,14 @@ unit-testing:
     DO +INSTALL_DEPENDENCIES
     DO +COPY_SOURCECODE
     RUN ./ci/unit-testing.sh
+
+
+releasing:
+    FROM ubuntu
+    RUN apt-get update
+    RUN apt-get install wget git -y
+    RUN wget https://github.com/cli/cli/releases/download/v2.29.0/gh_2.29.0_linux_amd64.tar.gz
+    RUN tar -xzvf gh_2.29.0_linux_amd64.tar.gz
+    RUN cp ./gh_2.29.0_linux_amd64/bin/gh /bin/gh
+    DO +COPY_METADATA
+    RUN --secret GH_TOKEN ./ci/releasing.sh

ci/releasing.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env sh
+
+set -o errexit
+set -o xtrace
+
+# Get current version.
+current_version=$(cat "VERSION")
+# If the tag already exist then exit.
+git tag -l | grep -q "^${current_version}$" && exit 0
+# Where to start generating the release notes from.
+base_commit=$(git rev-list --max-parents=0 HEAD)
+latest_tag=$(git describe --exact-match --tags || echo "")
+notes_from="${latest_tag:-${base_commit}}"
+# Generate the release notes.
+release_notes=$(git log --format="* %s" ${notes_from}.. --no-merges)
+# Create release and the tag.
+gh release create "${current_version}" --notes "${release_notes}"