Composer update pipeline in Bitbucket

bitbucket-pipelines.yml

pipelines:
  # Manually triggered Pipelines
  custom:
    composer-update:
      - step:
          name: Composer Update
          image: prooph/composer:<pick your version, e.g 7.4>
          script:
            - export COMPOSER_BRANCH="composer-update-auto-$(date +"%Y-%m-%d")"
            - git checkout -b "$COMPOSER_BRANCH"
            # This will depend on the version above, but probably can't hurt
            # as sometimes the github auth fails, since GH changed their key format
            - composer self-update
            # The GITHUB_TOKEN here is just to avoid rate limits. Define it in your pipeline variables
            - export COMPOSER_AUTH="{\"github-oauth\":{\"github.com\":\"$GITHUB_TOKEN\"}}"
            - composer install
            - composer update
            - git add composer.lock
            - git commit -m "Composer update from Bitbucket pipeline $(date +"%Y-%m-%d")"
            - git push origin
            # The pipeline variable PIPELINE_APP is an app password for the specific user, with PR open permission
            - sh "./bitbucket-pr.sh" "$COMPOSER_BRANCH" "Auto composer update $(date +"%Y-%m-%d")" "$PIPELINE_USER" "$PIPELINE_APP"

bitbucket-pr.sh

#!/bin/sh

source=$1
title=$2
user=$3
pass=$4
repo="<you can hard code this or make variable>"
team="<as above...>"

# You could change "master" below to something else
data=$(cat <<EOF
{
    "title": "$title",
    "source": {
        "branch": {
            "name": "$source"
        }
    },
    "destination": {
        "branch": {
            "name": "master"
        }
    },
    "close_source_branch": true
}
EOF
)

echo "Opening PR for branch $source in repo $repo. Title will be $title"

response=$(curl --write-out "%{http_code}" --silent --output /dev/null "https://api.bitbucket.org/2.0/repositories/$team/$repo/pullrequests" \
  -u "$user:$pass" \
  --request POST \
  --header "Content-Type: application/json" \
  --data "$data")

if [ "$response" -ne "200" ] && [ "$response" -ne "201" ]; then
  echo "ERROR opening PR: Status code was $response"
  exit 1
fi

echo "PR opened successfully"