Improve serverless-webpack compatibility

* Checks that the plugin order is correct if `serverless-webpack` is present
* Adds aserverless-webpack example
* Renames `iopipe_wrapper.js` to `iopipe-wrapper.js`
* Updates README to add serverless-webpack caveats/recommendations

Closes #19
Closes #25

README.md

@@ -102,6 +102,10 @@ This plugin currently supports the following AWS runtimes:
 * python3.6
 * python3.7
 
+### Using with serverless-webpack
+
+When using with [serverless-webpack](https://github.com/serverless-heaven/serverless-webpack) it is highly recommended to use the `nodejs10.x` runtime as this runtime does not require a helper script. For earlier Node.js runtimes a helper script is required which must be included via your `webpack.config.js`. The `serveless-iopipe-layers` plugin must follow the `serverless-webpack` plugin in your `serverless.yml`. See [here](https://github.com/iopipe/serverless-iopipe-layers/tree/master/examples/serverless-webpack) for an example.
+
 ## Limitations
 
 * Doesn't currently support local invocation

examples/serverless-webpack/package.json

@@ -14,7 +14,8 @@
   "license": "ISC",
   "devDependencies": {
     "serverless": "^1.38.0",
-    "serverless-webpack": "^5.3.1"
+    "serverless-webpack": "^5.3.1",
+    "webpack": "^4.35.2"
   },
   "dependencies": {}
 }

examples/serverless-webpack/serverless.yml

@@ -1,69 +1,20 @@
-service: iopipe-layers-plugin-example
+service: iopipe-layers-plugins-webpack-example
 
 provider:
   name: aws
   stage: prod
   region: us-east-1
+  runtime: nodejs10.x
 
 plugins:
-  - serverless-iopipe-layers/index.js
+  - serverless-webpack
+  - serverless-iopipe-layers
 
 custom:
     iopipe:
         debug: true
         token: ${env:IOPIPE_TOKEN}
 
 functions:
-  layer-nodejs610:
+  handler:
     handler: handler.handler
-    package:
-      exclude:
-        - ./**
-      include:
-        - handler.js
-    runtime: nodejs6.10
-
-  layer-nodejs810:
-    handler: handler.handler
-    package:
-      exclude:
-        - ./**
-      include:
-        - handler.js
-    runtime: nodejs8.10
-
-  layer-nodejs10:
-    handler: handler.handler
-    package:
-      exclude:
-        - ./**
-      include:
-        - handler.js
-    runtime: nodejs10.x
-
-  layer-python27:
-    handler: handler.handler
-    package:
-      exclude:
-        - ./**
-      include:
-        - handler.py
-    runtime: python2.7
-
-  layer-python36:
-    handler: handler.handler
-    package:
-      exclude:
-        - ./**
-      include:
-        - handler.py
-    runtime: python3.6
-
-  layer-python37:
-    handler: handler.handler
-    package:
-      exclude:
-        - ./**
-      include:
-        - handler.py
-    runtime: python3.7

examples/serverless-webpack/webpack.config.js

@@ -0,0 +1,6 @@
+const slsw = require('serverless-webpack');
+
+module.exports = {
+  entry: slsw.lib.entries,
+  target: 'node'
+};