Bash-Migration

Table of contents

• Bash-Migration
  • Table of contents
  • About the project
    • Features
  • Requirements
    • Notices
  • Commands
    • Extra information
      • Notice
  • How to use
  • Basic migration file
    • Information
  • How to use in a project
  • Extended usage

About the project

Bash-Migration is a tool for applying / reversing migrations to a server.

Features

• Apply migrations to your server
• Reverse migrations you don't need anymore
• Automatic rollback when an action failed
• Possibility to apply or reverse specific migrations
• Uses a semaphore to prevent running in parallel

Requirements

Name	Version	Description
bash	5.0.3	For running the BashMigration script
grep	3.3	For extracting informations from the filename
SQLite	3.28.0	As persistent data store

Notices

• Instead of bash you could also use zsh (tested with version 5.5.1)
• The sqlite3 command must be available in the command line.

Commands

Name	Description
migrate	Migrates all revisions which are located in the migrations directory
unmigrate	Reversing applied migrations
list	List the status of all migrations
version	Shows the current version

Extra information

The migrate and unmigrate both support arguments.

They support:

• all: Migrating / unmigrating all revisions
• <revision id>: Migrating / unmigrating a specific revision
• <revision id> <revision id>: Migrating / unmigrating multiple specific revisions

Notice

By default the all argument is used.

How to use

1. Create a directory called migrations
2. Create your first migration with the following pattern id_name_of_my_migration.sh
   1. ID is an integer
   2. The name is up to you for identifying what the migration does
3. Declare the functions migrateUp and migrateDown (see below for an example)
4. Fill both functions with the commands you would like to run
5. Run the migrate command
6. Be happy!

Basic migration file

Here is an example for a migration file

function migrateUp() {
    echo "Migrating up"

    return 0
}

function migrateDown() {
    echo "Migrating down"

    return 0
}

Information

When one of the functions returns the value 1, the action will be considered as unsuccessful and we rollback.

How to use in a project

• Initialize a git repository in an empty directory
• Add BashMigration as submodule: git submodule add -b master https://github.com/YannickFricke/BashMigration.git BashMigration
• Create the migrations directory
• Create your first migration file (as described)
• Start the script with ./BashMigration/BashMigration.sh migrate

You could also create a Makefile for easier usage.

Extended usage

Take a look into the wiki for additional informations.