Posts tagged ‘shell scripting’

Managing code releases

Recently I decided to streamline my code release process. I use subversion for my source control which means I push code live by running svn up on each of our production servers. I’m lazy, so I wanted an easier way to do this all at once. The end result is a simple shell script that lets me run svn update commands on multiple servers at once. It shows me the status of svn on each server and gives me chance to confirm that everything is okay before going ahead with the launch.

This example assumes you have two servers (app1 and app2) that are using public key authentication. Obviously, you’ll need to modify this script to work in your own environment. Make sure you replace “/var/www/” with your own document root and change to the IP address of each production server.


# connect to each server and echo their current status
echo "Connecting to app1...\n"
ssh 'cd /var/www/; svn status --show-updates; exit'
echo "\nConnecting to app2...\n"
ssh 'cd /var/www/; svn status --show-updates; exit'
# add additional servers here as needed
tput smso
# confirm the release before publishing
echo "\nDo you want to publish these changes to production? (y/n)\n"
tput rmso
read answer
if [ $answer == "y" ]; then
    # if "y", proceed with the release
    echo "\nPublishing to production..."
    echo "\nPublishing to app1..."
    ssh 'cd /var/www/; svn up; exit'
    echo "\nPublishing to app2..."
    ssh 'cd /var/www/; svn up; exit'
    # add additional servers here as needed
    echo "\nDone"
    # if "n", cancel the release.
    echo "\nCanceled"

How to start MAMP on port 80 without a password

I’m a big fan of MAMP. It’s the fastest way for anyone to get set up with a local PHP/MySQL development environment on a mac. One of the small annoyances with MAMP is that it requires you to enter your password all the time if you want to run it on port 80 (which I do). To be fair, it’s got more to do with UNIX security than MAMP… but it’s still bloody annoying!

I tried Steve Stringer’s technique of using launch daemons, but it just couldn’t get it to work for me.

The trick to getting MAMP to start behind the scenes is knowing that all that pretty GUI does is call a couple shell scripts. Specifically, those scripts are /Applications/MAMP/bin/ and /Applications/MAMP/bin/ (assuming you installed MAMP at the default location).

The second thing you should know is that must be run as root, but must be run as the current user. I created a new shell script to call those scripts appropriately:

sudo /Applications/MAMP/bin/
exit 0

I then added added an exception for that script to my sudoers file so I didn’t need to enter a password when I used sudo. The easiest way to add this exception is to use the ‘visudo’ command as root.

Finally, I used Automator to wrap the whole thing up as an application I could add to my dock. It works! One less daily annoyance in my life!

Since writing this, Damian Gaweda has posted a more elegant solution that’s worth checking out.