hack: Add script to sync Moby release notes from docs

hack/moby-sync-release.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+# Update the Github release notes to match the release notes from the docs.
+set -euo pipefail
+
+version="${1:-}"
+
+if [ -z "$version" ]; then
+    echo "Usage: $0 <version>"
+    exit 1
+fi
+
+moby="moby/moby"
+version="${version#v}" # remove the v prefix
+major_version="${version%%.*}" # get the major version (e.g. 29.0.3 -> 29)
+moby_tag="docker-v${version}"
+
+docs_notes=$(mktemp   -t new)
+github_notes=$(mktemp -t old)
+
+# Get the release notes from the docs.
+grep -A 10000 "## ${version}" "content/manuals/engine/release-notes/${major_version}.md" | \
+    grep -m 2 -A 0 -B 10000 '^## ' | \
+    sed '$d' | `# remove the last line` \
+    sed '/{{< release-date /{N;d;}' \
+    > "$docs_notes"
+
+# Get the release notes from the Github.
+curl -s "https://api.github.com/repos/$moby/releases/tags/${moby_tag}" | jq -r '.body' | sed 's/\r$//' > "$github_notes"
+
+docs_notes_diff=$(mktemp -t diff)
+# Copy docs_notes content and ensure it has exactly 2 blank lines at the end
+# Because Github for some reason adds an extra newline at the end of the release notes.
+sed -e :a -e '/^\n*$/{$d;N;ba' -e '}' "$docs_notes" > "$docs_notes_diff"
+printf '\n\n' >> "$docs_notes_diff"
+
+# Compare the release notes.
+if diff -u --color=auto "$github_notes" "$docs_notes_diff"; then
+    printf '\033[0;32mThe release notes are already up to date.\033[0m\n'
+    exit 0
+fi
+
+echo '========================================'
+printf '\033[0;34mTo update the release notes run the following command:\033[0m\n\n'
+echo gh -R moby/moby release edit "$moby_tag" --notes-file "$docs_notes"