ci: Use semantic-release for release automation

Configure this repository to use semantic-release [1] to manage
release generation.

[1]: https://github.com/semantic-release/semantic-release

Author: larsks

.github/workflows/release.yaml

@@ -0,0 +1,39 @@
+name: Release
+on:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  release:
+    name: Release
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      issues: write
+      pull-requests: write
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: "lts/*"
+
+      - name: Install packages
+        run: |
+          sudo apt-get -y install pandoc htmldoc
+
+      - name: Install npm dependencies
+        run: npm clean-install
+
+      - name: Release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: npx semantic-release

.gitignore

@@ -4,3 +4,4 @@
 picocom.1
 picocom.1.html
 picocom.1.pdf
+node_modules/

.releaserc.yaml

@@ -0,0 +1,13 @@
+repositoryUrl: https://github.com/picocom-ng/picocom
+branches:
+  - main
+plugins:
+  - - '@semantic-release/commit-analyzer'
+    - preset: conventionalcommits
+  - - '@semantic-release/release-notes-generator'
+    - preset: conventionalcommits
+  - - '@semantic-release/exec'
+    - prepareCmd: bash ci/make-release-tarball.sh ${nextRelease.version}
+  - - '@semantic-release/github'
+    - assets:
+        - path: release/*

ci/make-release-tarball.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+set -e
+
+version=$1
+ref="${2:-HEAD}"
+
+if [[ -z ${version} ]]; then
+	echo "ERROR: no version provided on command line" >&2
+	exit 1
+fi
+
+tmpdir=$(mktemp -d releaseXXXXXX)
+trap "rm -rf ${tmpdir}" EXIT
+
+builddir="${tmpdir}/picocom-${version}"
+
+echo "exporting release"
+git archive --prefix "picocom-${version}/" "$ref" | tar -C "$tmpdir" -xf -
+echo "VERSION=${version}" > "${builddir}/version.mk"
+
+echo "building docs"
+make -C "${builddir}" doc
+
+echo "building CONTRIBUTORS"
+cat > "${builddir}/CONTRIBUTORS" <<EOF
+The following people have contributed to the development of Picocom:
+
+EOF
+git log --format=format:%an | sort -u >> "${builddir}/CONTRIBUTORS"
+
+echo "building release tarball"
+mkdir -p release
+tar -C "$tmpdir" -cf "release/picocom-${version}.tar.gz" "picocom-${version}"
+
+echo "tarball content:"
+tar -tf "release/picocom-${version}.tar.gz"
+
+echo "exctracting pdf man page"
+tar --wildcards -C release -xf "release/picocom-${version}.tar.gz" --strip-components 1 "*/picocom.1.pdf" || :
+
+echo "release files:"
+ls -l release