GH-2259 - Add script to automatically backport commits.

Author: odrotbohm

Diff for: etc/backport-ticket.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+# Format $ticketNumber $targetVersion[]
+
+sourceGh="GH-$1"
+branch=$(git branch --show-current)
+json=$(gh issue view $1 --json=title,labels)
+
+title=$(echo $json | jq -r '.title')
+labels=$(echo $json | jq -r '.labels[].name' | paste -sd ',' -)
+
+number=$1
+
+# The SHAs of all commits associated with the source ticket
+shas=$(git log --grep="$sourceGh" --reverse --format="%H")
+
+# For each of the target versions
+for version in ${@:2}
+do
+	# Turn 1.5.6 into 1.5.x
+	targetBranch="$(echo "$version" | grep -oE '^[0-9]+\.[0-9]+').x"
+
+	# Checkout target branch and cherry-pick commit
+	echo "Checking out branch $targetBranch"
+	git checkout $targetBranch
+
+	# Cherry-pick all previously found SHAs
+	while IFS= read -r sha
+	do
+		echo "Cherry-pick commit $sha from $branch"
+		git cherry-pick $sha
+	done <<< $shas
+
+	echo "gh issue create --title \"$title\" --body \"Back-port of $sourceGh.\" --label \"$labels\" --assignee \"@me\" --milestone \"$version\""
+	number=$(gh issue create --title "$title" --body "Back-port of $sourceGh." --label "$labels" --assignee "@me" --milestone "$version" | awk -F '/' '{print $NF}')
+	echo "New ticket number: $number"
+
+	# Replace ticket reference with new one
+	targetGh="GH-$number"
+	expression="s/$sourceGh/$targetGh/g"
+	message=$(git log -1 --pretty=format:"%s" | sed $expression)
+
+	# Update commit message to refer to new ticket
+	echo "Adapt commit message from $sourceGh to $targetGh"
+	git commit --amend -m "$message"
+done
+
+# Return to original branch
+git checkout $branch