Mercurial to git synchronization utility

Docker image for mercurial to git synchronization utility.

The purpose of this image is to push commits from remote mercurial repository to remote git repository.

Suppose organization has internal mercurial repository and all employees push commits to this repository. And this organization decides to make some part of this repository public - to publish some code to, for example, GitHub. To avoid two repository maintenance, and to prevent mistakes like pushing to the wrong repository mercurial2git synchronization could be used.

In this case all employees still push their commits to internal mercurial repository. And synchronization job synchronizes mercurial repository with git repository.

This docker container automates synchronization routine.

Note. This is one-way synchronization. Git repository is a view of mercurial repository. No changes should be made in git repository. The only one way something can be placed in git repositry - is through mercurial repository.

Only specific branches are synchronized. For example, mercurial default branch is synchronized with git master branch. Or only release branches are synchronized, without any feature branches.

Installation

Installation from docker image

1. Pull docker image.
2. Proceed to configuration.

Installation from source

1. Pull project sources from version control system.
2. Make build executable:

   sudo chmod u+x ./build
   

3. Execute build:

   sudo ./build
   

4. Proceed to configuration.

Configuration

sudo docker run \
    --rm \
    -e MERCURIAL_REPO_URL='http://localhost/mercurial/repository' \
    -e GIT_REPO_URL='https://token@github.com/user/repository.git' \
    -e MERCURIAL_BRANCH_NAME_1='default' \
    -e GIT_BRANCH_NAME_1='master' \
        mercurial2git

Parameter	Value
MERCURIAL_REPO_URL	Mercurial repository URL
GIT_REPO_URL	Git repository URL
MERCURIAL_BRANCH_NAME_1	First mercurial repository branch
GIT_BRANCH_NAME_1	First git repository branch
MERCURIAL_BRANCH_NAME_2	Second mercurial repository branch
GIT_BRANCH_NAME_2	Second git repository branch
...	...
MERCURIAL_BRANCH_NAME_N	Last mercurial repository branch
GIT_BRANCH_NAME_N	Last git repository branch

Git branch name defaults to mercurial branch name and can be omitted.

sudo docker run \
    --rm \
    -e MERCURIAL_REPO_URL='http://localhost/mercurial/repository' \
    -e GIT_REPO_URL='https://token@github.com/user/repository.git' \
    -e MERCURIAL_BRANCH_NAME_1='default' \
    -e GIT_BRANCH_NAME_1='master' \
    -e MERCURIAL_BRANCH_NAME_2='featureX' \
        mercurial2git

In this example the default mercurial branch is synchronized with the master git branch, and the featureX mercurial branch is synchronized with the featureX git branch.

It is possible not to specify token in the command. In this case -it argument should be added to the run command.

sudo docker run ... -it ...

During the synchronization user will be prompted to specify the token (instead of username).

Cron job

1. Copy ./usr/bin/m2g to /usr/bin folder:

   sudo cp ./usr/bin/m2g /usr/bin
   

2. Make m2g executable:

   sudo chmod a+x /usr/bin/m2g
   

3. Edit /usr/bin/m2g and specify synchronization repository URLs and branches.
4. Create cron job:

   sudo crontab -l | { cat; echo "0 1 * * * /usr/bin/m2g <repository>"; echo ""; } | sudo crontab -
   

Donation

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