Cron – keeping a remote server up to date with git repo

crongitgithub

So, I'm aware of git hooks, and will be looking into those next, but want to write a simple bash script, run via cron, to keep a repo on a remote server up to date. I imagine it working like this:

cron executes myupdatescript.sh
myupdatescript.sh will:
1. cd into /my/sites/staging
2. git pull -q origin master
3. if something was pulled, then:
  - run grunt to build the source
  - yadda yadda yadda

I currently have this working as a cron task that looks like:

*/1 * * * * cd /my/sites/staging && git pull -q origin master && grunt production

I'm trying to avoid having to run my grunt build if nothing changed. I guess it all boils down to how can I tell if git pull actually pulled anything, and use that as a condition to running my grunt build. Ubuntu server, key is installed on github, all that good stuff. Thanks for any help!

Best Answer

I think you can solve this issue simply doing it:

*/1 * * * * cd /my/sites/staging && git pull -q origin master|grep -v "up-to-date" && grunt production

Related Solutions

Linux – Git Daemon on linux

Unfortunately this is probably a bug in msysgit http://code.google.com/p/msysgit/issues/detail?id=457

As of right now there is a workaround (not in the main branch I think) but no true fix.

Ssh publikkey authentication for git within a bash script

Use SSH agent forwarding. You will have to use an agent on your initial machine; you will also have to have agent forwarding enabled in your client and on your Linux server.

Assuming OpenSSH all around:

test -z "$SSH_AUTH_SOCK" && eval "$(ssh-agent)"
ssh-add -f /path/to/your/key-accepted-by-GitHub
ssh-add -f /path/to/your/key-accepted-by-your-user-on-the-linux-box
ssh -A userName@theLinuxBox /path/to/the/script

The sshd on your server (“yourLinuxBox”) will have to allow agent forwarding (AllowAgentForwarding in its sshd_config file; it usually defaults to “yes” if not present).

With your local agent holding the GitHub key and with agent forwarded through your SSH connection to the Linux box, any normal use of ssh on the Linux box that needs the key (e.g. git pull) will be able to use.

Or, you can use an entry in your .ssh/config to specify the bits of the “first leg” to abbreviate the last two commands as ssh backup-server /path/to/the/script (you will still have to make sure the GitHub key has been added to your local agent):

Host backup-server
    HostName     theLinuxBox # name or IP
    User         userName    # username on remote system
    IdentityFile /path/to/key-accepted-by-your-user-on-the-linux-box
    ForwardAgent yes

Note: Do not enable agent forwarding to untrusted servers (root on the server could use its local access to use keys stored in your local agent).

Best Answer

Related Solutions

Linux – Git Daemon on linux

Ssh publikkey authentication for git within a bash script

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