Script to create a pull request in github

create_pr.sh

#!/bin/bash
set -e

if [ $# -ne 3 ]; then
	echo "Insufficient arguments"
	echo "Usage: $0 github-org/repo-name production-branch your-branch"
	echo "Example: $0 openebs/velero-plugin master fix-123"
	exit 1
fi

if [ -z $USERNAME ] || [ -z $TOKEN ] || [ -z $EMAIL ]; then
	echo "No crendentials provided for giithub"
	echo -e "\033[1mThis script expects following environment variable for credentials\033[0m"
	echo -e "- \033[1mUSERNAME\033[0m"
	echo -e "   This is your github username, configured through \033[3mgit config --global user.name\033[0m"
	echo "   This script doesn't print your USERNAME on output"
	echo ""
	echo -e "- \033[1mTOKEN\033[0m"
	echo "   This is github token. This script doesn't print your TOKEN on output."
	echo "   To create a new token,"
	echo "   refer https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line"
	echo ""
	echo -e "- \033[1mEMAIL\033[0m"
	echo -e "   This is your email id, configured through \033[3mgit config --global user.email\033[0m, to sign the commit"
	echo "   This script doesn't print your EMAIL on output"
	echo ""
	exit 1
fi

EDITOR=vim
BRANCH=$3
GIT_URL="https://api.github.com/repos/${1}/pulls"
GIT_REPO=$1
GIT_PRODUCTION_BRANCH=$2


get_input() { 
        local f=$1
        $EDITOR $f
}

get_title() {
        local -n d=$1
        f=$(mktemp)
        echo "#ADD PR TITLE BELOW" >> ${f}
        get_input $f
        sed -i '/#ADD PR TITLE BELOW/d' $f
        d=$(cat $f)
        rm $f
}

get_body() {
        local -n d=$1
        f=$(mktemp)
        o=$(mktemp)
        echo "#ADD PR MESSAGE BELOW" >> ${f}
        get_input $f
        sed -i '/#ADD PR MESSAGE BELOW/d' $f
	cat $f | while read line; do echo -n "$line\r\n" >> $o; done
        d=$(cat $o)
        rm $f $o
}


#PR title
PR_TITLE=""
#PR description
PR_MSG=""

get_title PR_TITLE
get_body PR_MSG

HEAD="$USERNAME:$BRANCH"

# update_remote adds new remote with username and repo_name
update_remote() {
	echo "Updating remote"
	git config --global user.name ${USERNAME}
	git config --global user.email ${EMAIL}
	local repo_name=$(echo $GIT_REPO | cut -d '/' -f2)
	git remote add upstream https://${USERNAME}:${TOKEN}@github.com/$USERNAME/$repo_name.git > /dev/null 2>&1
	rc=$?
	if [[ $rc -eq 0 ]] || [[ $rc -eq 128 ]]; then
		return 0
	fi
	return $rc
}

#push_branch push upstream to github
push_branch() {
	echo "Pushing commit to github"
	git push upstream $BRANCH
}

update_remote && push_branch
rc=0
if [ $rc -ne 0 ]; then
	echo "Branch related operation failed"
	exit 1
fi

# file to store curl output
RESP_FILE=$(mktemp)
EXIT_CODE=0

PR_CREATE_DATA='{
	"title": "'${PR_TITLE}'",
	"body": "'${PR_MSG}'",
	"head": "'${HEAD}'",
	"base": "'${GIT_PRODUCTION_BRANCH}'"
}'

res=$(curl -u ${USERNAME}:${TOKEN} --silent \
	-w "%{http_code}" \
	--output ${RESP_FILE} \
	--url ${GIT_URL} \
	--request POST	\
	--header 'content-type: application/vnd.github.VERSION.raw+json'\
	--data "$PR_CREATE_DATA"
)

# if response value is 201 then PR is created successfully
# Refer https://developer.github.com/v3/pulls/#response-2
if [ $res != "201" ]; then
	echo "Error: Unable to create a PR for changelog.. REST API output is as below"
	cat ${RESP_FILE}
	EXIT_CODE=1
else
	echo "Successfully raised a PR for changelog"
fi

rm -rf ${RESP_FILE}

exit ${EXIT_CODE}

Before creating a PR, you need to setup few environment variables.
This script expects following environment variable for credentials

• USERNAME
  This is your github username, configured through git config --global user.name
  This script doesn't print your USERNAME on output

• TOKEN
  This is github token. This script doesn't print your TOKEN on output.
  To create a new token,
  refer https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line

• EMAIL
  This is your email id, configured through git config --global user.email, to sign the commit
  This script doesn't print your EMAIL on output

To create a PR:

• Set environment variable
• Create a branch(ley say, branch-1) on your local workspace
• Create new commits in branch branch-1.
• Execute following command to create PR:

./create_pr.sh github-org/repo-name target_branch_for_pr branch-1