A github bot for merging & updating pull requests with a label.

Functionality

This bot can merge and keep your branches up to date with the latest changes from base (master/main).

Config file

Place merge-with-label.yml in .github repository:

version: 1
merge:
  # specify a list of labels that indicate whether a pull request is eligible
  # for merging (regex)
  # (or-list, only one label must be present on a pull request)
  # (leave empty to disable the merge feature)
  labels:
    - "merge"
  # strategy to merge (can be "commit", "squash" or "rebase")
  strategy: "squash"
  # amount of required approvals before merging
  #requiredApprovals: 1
  # specify a list of users that are required for review (regex)
  # (and-list, all users need to approve)
  #requireApprovalsFrom:
  #  -
  # names of the checks that are need to pass before merging (regex)
  # (and-list, all checks need to pass)
  requiredChecks:
    - ".*"
  # require a linear history
  requireLinearHistory: false
  # delete branch after merging
  deleteBranch: true
  # never merge pull requests that were created by these users (regex)
  #ignoreFromUsers:
  #  - "dependabot"
  # never merge pull requests that match one of these titles (regex)
  #ignoreWithTitles:
  #  - "chore:.+"
  # never update pull requests that match one of these labels (regex)
  #ignoreWithLabels:
  #  - "dont-merge"
update:
  # specify a list of labels that indicate whether a pull request is eligible
  # for updating (regex)
  # (or-list, only one label must be present on a pull request)
  # (leave empty to disable the update feature)
  labels: 
    - "update-branch"
  # never update pull requests that were created by these users (regex)
  ignoreFromUsers:
    - "dependabot"
  # never update pull requests that match one of these titles (regex)
  #ignoreWithTitles:
  #  - "chore:.+"
  # never update pull requests that match one of these titles (regex)
  #ignoreWithTitles:
  #  - "chore:.+"
  # never update pull requests that match one of these labels (regex)
  #ignoreWithLabels:
  #  - "dont-update"

Setup

1. Create a new github app with following permissions & events

   Repository Permissions

   Permission	Level
   Actions	Read
   Checks	Read and write
   Commit statuses	Read-Only
   Contents	Read and write
   Metadata	Read-Only
   Pull requests	Read and write
   Workflows	Read and write

   Subscribe to events

   • Check run
   • Pull request
   • Pull request review
   • Push

2. Create a private key and save it

3. Note down the app id

4. Spin up the instance somewhere using docker compose

   docker-compose.yml

   version: '3.9'
   services:
     nats:
       image: nats:2.9.20
       restart: unless-stopped
       command: ["--js", "-user", "nats", "-pass", "425751fd-62e2-4b73-9e1b-5a9b0dafc5ad"]
   
     server:
       image: ghcr.io/eun/merge-with-label:latest
       restart: unless-stopped
       command: "server"
       ports:
         - "8000:8000"
       environment:
         PORT: 8000
         NATS_URL: nats://nats:425751fd-62e2-4b73-9e1b-5a9b0dafc5ad@nats:4222
       depends_on:
         - nats
   
     worker:
       image: ghcr.io/eun/merge-with-label:latest
       restart: unless-stopped
       command: "worker"
       volumes:
         - "./private-key.pem:/private-key.pem:ro"
       environment:
         NATS_URL: nats://nats:425751fd-62e2-4b73-9e1b-5a9b0dafc5ad@nats:4222
         APP_ID: <your app id>
         PRIVATE_KEY: /private-key.pem
       depends_on:
         - server
   

   Make sure you fill in your app id, provide the private-key.pem file and modify the nats username and password

5. Point the webhook url to the deployment

Fine Tuning Settings

Following environment variables are available

Variable	Default Value
AllowedRepositories	.*
AllowOnlyPublicRepositories	false
BotName	merge-with-label
StreamName	mwl_bot_events
PullRequestSubject	pull_request
PushSubject	push
MessageRetryAttempts	5
MessageRetryWait	15s
RateLimitBucketName	mwl_rate_limit
RateLimitBucketTTL	24h
RateLimitInterval	30s
AccessTokensBucketName	mwl_access_tokens
AccessTokensBucketTTL	24h
ConfigsBucketName	mwl_configs
ConfigsBucketTTL	24h
CheckRunsBucketName	mwl_check_runs
CheckRunsBucketTTL	10m
DurationBeforeMergeAfterCheck	10s
DurationToWaitAfterUpdateBranch	30s
MaxMessageAge	10m
MessageChannelSizePerSubject	64

Additionally, you can enable debug logging by setting the DEBUG environment variable to true.

Build History