Weapon of Choice

There is a Git command, filter-branch, which works wonders for changing the history of a repository, but it’s difficult to use because it forces you to know how Git works under the hood. Instead there is this little free tool, BFG Repo-Cleaner, which is intuitive, fast and recommended.

Check that there are some occurrences of your string

The first thing to do is to check that the repository contains the string you want to replace with another string. This will help later to make sure you effectively replaced it.

andrea at Lock-and-Stock in ~/dev/ruby
$ git clone git@gitlab.com:aercolino/your-repository.git

andrea at Lock-and-Stock in ~/dev/ruby
$ cd your-repository

andrea at Lock-and-Stock in ~/dev/ruby/your-repository
$ git log -G"your string" -i --all
commit ...
Author: ...
Date:   ...

    Message 2

commit ...
Author: ...
Date:   ...

    Message 1

Notice that, on the above git log line, the -G option allows to specify a regular expression, and the -i option allows to  ignore case.

Install BFG

BFG needs a JVM and you can install one with brew on a Mac.

$ brew cask install java
$ brew install bfg

Create search-replace.txt

BFG takes a file for specifying the text to search and replace. The accepted format is one replacement per line, like SEARCH==>REPLACE, with optional prefixes regex:, and glob:.

regex:your string==>another string

Use BFG

BFG acts on a bare repository which you can get by cloning with the --mirror option. Make sure the last commit doesn’t contains the text to be replaced, otherwise add a clean commit and push it before cloning.

andrea at Lock-and-Stock in ~/dev/ruby
$ git clone --mirror git@gitlab.com:aercolino/your-repository.git

andrea at Lock-and-Stock in ~/dev/ruby
$ bfg --replace-text search-replace.txt your-repository.git

andrea at Lock-and-Stock in ~/dev/ruby
$ cd your-repository.git

andrea at Lock-and-Stock in ~/dev/ruby/your-repository.git
$ git reflog expire --expire=now --all && git gc --prune=now --aggressive

Backup the old your-repository

You can recover this backup analogously to the section below.

andrea at Lock-and-Stock in ~/dev/ruby
$ git clone --mirror git@gitlab.com:aercolino/blog-experiment.git blog-experiment.git.backup

Create a new your-repository

This step involves removing your remote old repository and creating a remote new one with the same name as before. Then you can push to it from your local repository using the --mirror option.

andrea at Lock-and-Stock in ~/dev/ruby/your-repository.git
$ git push origin --mirror

Check that your string was replaced by another string

If all is OK then you should see no results when searching again for your string but at least the same number of results you got when looking for it before if you now look for the replacement string.

andrea at Lock-and-Stock in ~/dev/ruby
$ git clone git@gitlab.com:aercolino/your-repository.git

andrea at Lock-and-Stock in ~/dev/ruby
$ cd your-repository

andrea at Lock-and-Stock in ~/dev/ruby/your-repository
$ git log -G"your string" -i --all
(nothing shown)

andrea at Lock-and-Stock in ~/dev/ruby/your-repository
$ git log -G"another string" -i --all
commit ...
Author: ...
Date:   ...

    Message 2

commit ...
Author: ...
Date:   ...

    Message 1

 

With individual Docker commands

1. Install Docker for Mac
2. $ docker run –name mysql-latest -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:latest
3. $ docker run –name wordpress -p 8000:80 –link mysql-latest:mysql -d wordpress:4.7.3-php7.1-apache
4. Visit http://0.0.0.0:8000 and configure WordPress

With a Docker compose file

1. Install Docker for Mac
2. Save the following text to a ´~/dev /wordpress /website /docker-compose.yml´ file:

   version: '2'
   
   services:
     dbms:
       image: mysql:5.7
       volumes:
         - db_data:/var/lib/mysql
       ports:
         - 32768:3306
       restart: always
       environment:
         MYSQL_ROOT_PASSWORD: wordpress
         MYSQL_DATABASE: wordpress
         MYSQL_USER: wordpress
         MYSQL_PASSWORD: wordpress
   
     wordpress:
       depends_on:
         - dbms
       build: ./docker/wordpress
       image: wordpress:xdebug
       volumes:
         - .:/var/www/html
       ports:
         - 8000:80
       restart: always
       environment:
         WORDPRESS_DB_HOST: dbms:3306
         WORDPRESS_DB_PASSWORD: wordpress
         XDEBUG_CONFIG: remote_host=192.168.1.33
   
   volumes:
       db_data:

3. Save the following text to a ´~/dev /wordpress /website /docker /wordpress /Dockerfile´ file

   FROM wordpress:4.7.3-php7.1-apache
   
   RUN yes | pecl install xdebug 
       && echo "zend_extension=$(find /usr/local/lib/php/extensions/ -name xdebug.so)" > /usr/local/etc/php/conf.d/xdebug.ini 
       && echo "xdebug.remote_enable=on" >> /usr/local/etc/php/conf.d/xdebug.ini 
       && echo "xdebug.remote_autostart=off" >> /usr/local/etc/php/conf.d/xdebug.ini

4. Run everything: ´$ docker-compose up´
5. Visit http://0.0.0.0:8000 and configure WordPress

Connect to the running dbms server from SequelPro

1. Select the Standard tab
2. Configure:

   Name: Docker for WordPress
   Host: 0.0.0.0
   Port: 32768
   Username: wordpress
   Password: wordpress

3. Connect

Connect to a running server from a terminal

Example relative to connecting to the running dbms server.

1. Find out the name of the server:

   $ docker-compose ps
          Name                      Command               State            Ports
   --------------------------------------------------------------------------------------
   website_dbms_1        docker-entrypoint.sh mysqld      Up      0.0.0.0:32768->3306/tcp
   website_wordpress_1   docker-entrypoint.sh apach ...   Up      0.0.0.0:8000->80/tcp

2. Connect to the ´website_dbms_1´ server:

   $ docker exec -it website_dbms_1 bash
   root@7d36d19c7df4:/#

3. Then, for example, find out the server IP:

   root@7d36d19c7df4:/# hostname -I
   172.18.0.2