ENVMGR

IT MANAGES YOUR ENV.

envmgr is a simple application that will load environment variables for your app from a directory of config files.

Why would you want to do that? Perhaps you have a suite of applications which all need to know about some common resources, but which also have app-specific configurations. Here's how you'd achieve that with envmgr:

$ ENVMGR_ROOT=~/.envmgr
$ mkdir -p "$ENVMGR_ROOT"
$ cd "$ENVMGR_ROOT"

$ cat >common.conf <<EOM
SQL_URI="postgresql://user:pass@host..."
ENVIRONMENT=production
EOM

$ cat >app_a.conf <<EOM
include common
APP_NAME=application_alpha
USER=maurice
EOM

$ cat >app_b.conf <<EOM
include common
APP_NAME=application_beta
USER=norman
EOM

With your config files created, you can now run your applications through envmgr:

$ envmgr -r "$ENVMGR_ROOT" -n app_a python run_app_a.py
$ envmgr -r "$ENVMGR_ROOT" -n app_b bundle exec ruby run_app_b.rb

Config syntax

include

include other/file

The include directive does what it says on the tin: includes directives from another file. In the above example, envmgr will attempt to load directives from $ENVMGR_ROOT/other/file.conf.

NB: you cannot include files that live outside of $ENVMGR_ROOT.

NB: envmgr makes no attempt to detect cycles when processing the include directive. If you create such cycles then expect envmgr to blow up in your face.

clear

clear

Completely clear the environment. When used, this directive will usually come at the beginning of a config file.

unset

unset HOME

Unset the specified environment variable

etc.

Any other nonblank lines will be interpreted by envmgr as attempts to set an environment variable:

FOO=bar
BAR="baz"
BAZ='bat'

Anything that doesn't conform to one of the above patterns will probably raise a ParseError and the baby Jesus will cry. Or something.

As of version 0.0.3, envmgr will do some basic interpolation for you:

NAME=Marcus
HELLO_MARCUS="Hello, $NAME"       # this will be "Hello, Marcus"
HELLO_UNDEF="Hello, $IDONTEXIST"  # this will be "Hello, "
HELLO_SINGLES='Hello, $NAME'      # this will be "Hello, $NAME"

NB: one gotcha is that envmgr does not use a shell-compliant lexer at the moment, so the following will not work as you might expect:

NAME=Marcus
HELLO_ESCAPED="Hello \$NAME"      # Gotcha! this will be "Hello \Marcus"

Hacking

Make yourself a virtualenv, and then, in a checked out copy of this repository, run:

pip install -e .

To run the tests, you should do:

pip install tox
tox