Build configuration for multiple environments.

[lejoe]

We want to modify our gulp tasks so that when we give them an env it optimises some things (like minifying JS, CSS, HTML).
Also add sourcemaps for scripts on dev build

[peterbraden]

I'm changing the title of this to reflect the fact that this issue is about having multiple environment specific configurations. Things such as minification etc will use these configs, and can be addressed individually in subsequent tickets.

[peterbraden]

My requirements / nice-to-haves:

• Configuration should be just JSON files. Having logic in config leads to hard to reproduce edge cases.
• Default configuration should support local development without any modification.
• Example production configuration file, with placeholders for SSH key paths, or tokens etc.

[peterbraden]

Example solution:

var env = process.env.NODE_ENV || 'development'
  , cfg = JSON.parse(fs.readFileSync('./config.'+env))

module.exports = cfg;

There's also:

• https://github.com/lorenwest/node-config
• https://github.com/motdotla/dotenv

[lejoe]

Our environments are here: https://github.com/ginetta/skeleton/blob/master/gulp/config.js#L77

Not keen on moving this to a JSON file. there will be so much repetition and it will become hard to modify for each project. There's no logic in there except variable re-use.

[peterbraden]

On the contrary, I think doing this right with JSON will reduce repetition. The variable re-use in the config is a code smell to me. Additionally, having all of the environments in one file means that we can't specify things like credentials, servers or keys without having these in source control, which is something we definitely don't want.

See http://12factor.net/config for my rationale.

[peterbraden]

For example, the environment config we have here is a layer of indirection between the arguments passed to the tool and the tool. That's why we ended up with deploy.sh. I'm looking for a solution where npm run deploy does the right thing automatically depending on the environment it's on. This can involve env variables etc.

[peterbraden]

ie: at the moment the flow is as follows:

1. Snap CI builds with gulp build
2. Snap CI runs deploy.sh
3. Depending on the $SNAP_PULL_REQUEST_NUMBER and $SNAP_BRANCH environment variables, deploy.sh runs gulp deploy with various combinations of arguments.

I want to refactor that to:

1. Snap CI builds with npm run build
2. Snap CI deploys with npm run deploy
3. The deploy script runs with the appropriate configuration drawn from the environment.

[lejoe]

Sounds good to me.
I don't see why we need another config file though.
Something like this would work, right? https://gist.github.com/lejoe/cd0a2f69e430f782861a

[peterbraden]

But there's so much repetition in there, and the information is still outside the config. The idea with something like https://github.com/motdotla/dotenv is that you get rid of this config, and simply maintain a series of ENV files.

[peterbraden]

This is an interesting post: http://blog.keithcirkel.co.uk/how-to-use-npm-as-a-build-tool/