Setting environment variables with puppet - ruby

Question

I'm trying to work out the best way to set some environment variables with puppet.
I could use exec and just do export VAR=blah. However, that would only last for the current session. I also thought about just adding it onto the end of a file such as bashrc. However then I don't think there is a reliable method to check if it is all ready there; so it would end up getting added with every run of puppet.

Answer 1

I would take a look at this related question.
*.sh scripts in /etc/profile.d are read at user-login time (as the post says, at the same time /etc/profile is sourced)
Variables export-ed in any script placed in /etc/profile.d will therefore be available to your users.
You can then use a file resource to ensure this action is idempotent. For example:
file { "/etc/profile.d/my_test.sh":
content => 'export MYVAR="123"'
}

Answer 2

Or an alternate means to an indempotent result:
Example
if [[ ! grep PINTO_HOME /root/.bashrc | wc -l > 0 ]] ; then
echo "export PINTO_HOME=/opt/local/pinto" >> /root/.bashrc ;
fi
This option permits this environmental variable to be set when the presence of the
pinto application makes it warrented rather than having to compose a user's
.bash_profile regardless of what applications may wind up on the box.

Answer 3

If you add it to your bashrc you can check that it's in the ENV hash by doing
ENV[VAR]
Which will return => "blah"

Answer 4

If you take a look at Github's Boxen they source a script (/opt/boxen/env.sh) from ~/.profile. This script runs a bunch of stuff including:
for f in $BOXEN_HOME/env.d/*.sh ; do
if [ -f $f ] ; then
source $f
fi
done
These scripts, in turn, set environment variables for their respective modules.

Answer 5

If you want the variables to affect all users /etc/profile.d is the way to go.
However, if you want them for a specific user, something like .bashrc makes more sense.
In response to "I don't think there is a reliable method to check if it is all ready there; so it would end up getting added with every run of puppet," there is now a file_line resource available from the puppetlabs stdlib module:
"Ensures that a given line is contained within a file. The implementation matches the full line, including whitespace at the beginning and end. If the line is not contained in the given file, Puppet appends the line to the end of the file to ensure the desired state. Multiple resources can be declared to manage multiple lines in the same file."
Example:
file_line { 'sudo_rule':
path => '/etc/sudoers',
line => '%sudo ALL=(ALL) ALL',
}
file_line { 'sudo_rule_nopw':
path => '/etc/sudoers',
line => '%sudonopw ALL=(ALL) NOPASSWD: ALL',
}