Grunt: How to change config strings for different environments - node.js

Question

I have a python file as part of my grunt workflow. I have defined two build tasks:
build:dev
build:release
When I compile 'build:dev', I want to add this line to my python file:
...
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + dbpath
...
When I compile 'build:release', I want to add this line to my python file:
...
app.config['SQLALCHEMY_DATABASE_URI'] = os.environ['POSTGRESQL_COLORFUL_URL']
...
edit: fixed typo in code and title

Answer 1

You can use grunt-sed.
It's a really useful 'find and replace' system that builds into Grunt.
From the docs:
npm install grunt-sed
Add this line to your project's Gruntfile.js:
grunt.loadNpmTasks('grunt-sed');
Then in your build:dev and build:release tasks have the following:
sed: {
database_uri: {
path: 'path_to_your_python.py',
pattern: '%PATTERN_IN_YOUR_PYTHON_FILE%',
replacement: '\'sqlite:///\' + dbpath',
}
}
In your python file you want replacing you must also have %PATTERN_IN_YOUR_PYTHON_FILE% to be replaced.

Answer 2

I've used a plugin called grunt-string-replace that worked very well for what I needed to do. Also, I added some custom code in my Gruntfile.js to read different environment configurations and customize the build output based on that.
I detailed the full deployment script in this post: http://dev-blog.cloud-spinners.com/2014/02/complete-grunt-deployment-workflow-for.html
I hope you find that useful.