Working with git
Overview
Most work I do is out on github in public repos that anyone can access, search for geo-ceg and brian32768. I can't put every bit of my life out on the Internet, so I still operate my own Git server for proprietary projects. I also work in other peoples' servers for projects.
This page contains notes both on Github and on using private Git servers.
Github.com migration
I have migrated most of my shareable projects to github.com to get them off my own server. Pretty much all the same git commands below work.
Migration: Use the Github Importer.
I used the command line importation. Basically you pull the repo with all its history onto your local machine then push it up to github. In brief
- Create the repository first at github, "ssurgo" in this case.
- Make a copy of your existing repo: git clone --bare [email protected]:contours.git
- cd ssurgo.git/
- Push everything up to github: git push --mirror https://github.com/geo-ceg/ssurgo.git
- cd ..
- Make sure it works! git clone [email protected]:Geo-CEG/ssurgo.git
- If it worked you have a directory "ssurgo" now. Remove the bare repo: rm -rf ssurgo.git
- Try commiting by making a README. emacs README.me
- git add README.md
- git commit -a -m "added README!"
- git push
Use case: web app development
One of the main reasons I want my own git server is so that I can sync a web app between my laptop and a server.
My work flow: I develop on the laptop, then I push changes to the git server, then I pull the changes down into the live web server.
The theory is that if the live server breaks after an update, I can revert the changes.
Use case: Asterisk servers
Each server needs tweaks to its configuration. When you are bending config files and something stops working you need to be able to back out the changes.
File ownerships and access control
Access to the server is through ssh. The repositories will be owned by the user 'git'. So I put the home for user 'git' where I want the repositories to be; on Bellman I use /green/repositories. Then I set up ssh with keys so that I don't need to share passwords.
I put create a separate 'git' key pair and put the public key into ~git/.ssh/authorized_keys I can test it with "ssh [email protected] list", this should list the available repos and exit.
Once that's all in place I don't need a complete path for the "remote" command, just one relative to git's home.
Creating a new private repo
See also: http://www.git-scm.com/book/en/v2/Git-on-the-Server-Setting-Up-the-Server
I am using ssh for file transfer.
I find it easiest to create a new empty repo directly on the server and then push existing content into it.
ssh bellman cd ~git sudo git init --bare myproject.git create a bare repository sudo chown -R git.wildsong myproject.git exit cd Projects assuming myproject is a folder containing the files you want in a repo cd myproject git init make a gitignore file in myproject git add some files git commit -m 'initial commit' git remote add origin [email protected]:myproject.git git push origin master this pushes committed files from the local repository to the master branch on the remote machine
Now I should be able to clone my project onto the web server and start using git to keep it updated.
ssh webserver cd /var/www/appserver git clone git.wildsong.biz:myproject.git
On my copy I need to define the remote repo,
git remote add origin [email protected]:myproject.git
When I make changes on the local laptop, first I commit them locally.
git commit
..then I push them up to the git server
git push origin master
..then I pull them down onto the public web server
git fetch
Then I create a virtualenv and load the requirements.
cd myproject virtualenv env source env/bin/activate pip install -r requirements.txt python run.py
Github collaboration
Now I want to contribute to someone's project. This description is good especially after reading the comments section too.
http://blog.davidecoppola.com/2016/11/howto-contribute-to-open-source-project-on-github/
Briefly, leaving out some critical steps...
- Fork -- Makes a copy of the project in Github that I can change
- Clone -- Pull the code down from Github to my computer
- Branch -- I will work in a branch and then remove it when done
- Edit -- Make proposed changes
- Issue pull request -- Notifies project owner; hopefully it will be accepted
Branching and all that
This explanation is pretty good. Darn good. http://longair.net/blog/2009/04/16/git-fetch-and-merge/
Git submodules
I keep some code in github, and I want to incorporate it into a project. I can use the submodule feature.
cd myproject git submodule add [email protected]:brian32768/pyst2.git
This clones pyst2 into a subdirectory (called pyst2 by default) Now I can work on pyst2 and do commits and pushes but it remains separate from 'myproject'. If I ask for status...
git status On branch master Your branch is up-to-date with 'origin/master'. Changes to be committed: (use "git reset HEAD <file>..." to unstage)
modified: .gitmodules new file: pyst2
If I am in a virtualenv then I can cd into pyst2 and do 'python setup.py install' and the right thing will happen.
When you clone a new copy or update an existing clone (git pull) then the submodules will be there but empty, you have do do this
cd pyst2 (or whatever your submodule folder is) git submodule init git submodule update
That will tell git to populate the submodule folder with code from the other repository.
Git in Docker
Docker mania! This one looks good. It is built on alpine and it has support for keys and data in volumes. Should drop right in on Bellman and replace the system level version.