bustlelabs/shep

# Migrations for 0.X to 1.0 and 2.X to 3.0

## Migrating from shep 0.X to shep 1.0

- Shep 1.0 only supports node 4.3. Make sure all functions are using the `callback` style instead of the old `context.done()` methods
- Remove `node_modules` and `package.json` from individual function folders. Shep 1.0 installs all the modules at the project level and then uses webpack to ensure only necessary modules are included in your build.
- Add a `lambda.json` file to your root directory. This will be the default lambda settings for every function. They will be overridden by anything in each functions `lambda.json` file
example:

```json
{
  "Handler": "index.handler",
  "MemorySize": 128,
  "Role": "",
  "Timeout": 10,
  "Runtime": "nodejs4.3"
}
```



- Each function folder should have it's own `lambda.json file`. Any settings in here will override the project level settings. Important! Shep used to have function namespacing built in but now this is up to the end user. Functions are generated with the following lambda.json by default:

```json
{
  "FunctionName": "$PROJECT_NAME-$FUNCTION_NAME",
  "Description": ""
}
```


- Remove all symlinks and instead reference the file directly. Webpack will handle bundling these files for you.
- Remove `lib` directories for each function
- Create `function/events` for each function
- Move `event.json` for each function into `function/events` and name it whatever descriptive thing you like
- Add `dist/*` to .gitignore
- Change all files in `config/` from `.json` to `.js`. Add `module.exports = ` to the beginning of each file
- Use config by importing it at the top of your file like: `import config from 'shep-config'`. This is not a real module, but an alias that will be handled by webpack.
- Run `shep pull --api-id foo --stage bar`. You'll need the API gateway ID from AWS and to specify the stage (beta or production). This will pull down a swagger representation of the latest deployed API for your project. This will now be imported/exported to manage changes with API Gateway.
- Add a webpack.config.js file to the project root.

Example:
``` js
const path = require('path')

module.exports = function(name, env) {
  return {
    target: 'node',
    entry: {
      [name]: path.resolve(`functions/${name}/index.js`)
    },
    output: {
      path: path.resolve(`dist/${name}`),
      filename: 'index.js',
      chunkFilename: '[name]/[id].js',
      libraryTarget: 'commonjs2'
    },
    resolve: {
      modules: [ 'node_modules', 'lib' ],
      alias: { 'shep-config': path.resolve(`config/${env}.js`) }
    },
    externals: { 'aws-sdk': 'aws-sdk' },
    module: {
      loaders: [
        {
          test: /.json$/,
          loader: 'json-loader'
        }
      ]
    }
  }
}
```

## Migrating from shep 2.X to shep 3.0

- Shep 3.0 undoes changes in 2.X that added shep-config as a js module. In 3.0, your config should be
json, and it should live inside the `/environments` directory
- Environment vars are now stored on `process.env`, like `process.env.ENV`. 
- Capitalize all config keys inside environment files
- `shep run` accepts custom process.env key value pairs, e.g., `DB_TABLE=custom shep run ${functionName}`

## Migrating from shep 3.X to shep 4.0

- Shep 4.0 now handles environment variables in the configuration of AWS Lambda Functions. If you have no undeployed changes in your `/environments` directory, then you should be able to safely delete the directory and use your exisiting project with shep `4.0.0`. See the docs for `shep config` to add, remove, list, and sync environment variables for your functions.