Add AWS Lambda Layer Support

index.js

@@ -32,7 +32,6 @@ class ServerlessPythonRequirements {
         slimPatterns: false,
         slimPatternsAppendDefaults: true,
         zip: false,
-        inject: true,
         layer: false,
         cleanupZipHelper: true,
         invalidateCaches: false,
@@ -98,8 +97,6 @@ class ServerlessPythonRequirements {
       options.dockerImage = options.dockerImage || defaultImage;
     }
     if (options.layer) {
-      // If layers are being used, dependencies should not be injected.
-      options.inject = false;
       // If layer was set as a boolean, set it to an empty object to use the layer defaults.
       if (options.layer === true) {
         options.layer = {};

lib/inject.js

@@ -72,7 +72,8 @@ function moveModuleUp(source, target, module) {
  * @return {Promise} the combined promise for requirements injection.
  */
 function injectAllRequirements(funcArtifact) {
-  if (!this.options.inject) {
+  if (this.options.layer) {
+    // The requirements will be placed in a Layer, so just resolve
     return BbPromise.resolve();
   }
 

lib/layer.js

@@ -2,31 +2,62 @@ const BbPromise = require('bluebird');
 const fse = require('fs-extra');
 const path = require('path');
 const JSZip = require('jszip');
-const { writeZip, addTree } = require('./zipTree');
+const {
+  writeZip,
+  addTree
+} = require('./zipTree');
 
 BbPromise.promisifyAll(fse);
 
+/**
+ * Get the paths for the compatible runtimes of the layer
+ * @param {string[]} list of runtime paths
+ */
+function getRunTimeBuildPaths() {
+  const runtimepaths = {
+    'python2.7': 'python',
+    'python3.6': path.join('python', 'lib', 'python3.6', 'site-packages'),
+    'python3.7': path.join('python', 'lib', 'python3.7', 'site-packages'),
+  };
+
+  let runtimes = []
+
+  // Defer to Layer config first
+  if (this.options.layer.compatibleRuntimes) {
+    runtimes = this.options.layer.compatibleRuntimes;
+    // If none provided, assume the provider runtime
+  } else if (this.serverless.service.provider.runtime) {
+    runtimes = [this.serverless.service.provider.runtime];
+    // If still no runtime found, just assume latest python
+  } else {
+    runtimes = ['python3.7'];
+  }
+
+  return BbPromise.resolve(runtimes.map(runtime => runtimepaths[runtime]));
+}
+
 /**
  * Zip up requirements to be used as layer package.
+ * @param {string[]} list of paths where the requirements should be put in the layer
  * @return {Promise} the JSZip object constructed.
  */
-function zipRequirements() {
-  return addTree(new JSZip(), path.join('.serverless', 'requirements')).then(
-    zip => writeZip(zip, path.join('.serverless', 'pythonRequirements.zip'))
-  );
+function zipRequirements(runtimepaths) {
+  const rootZip = new JSZip();
+  const src = path.join('.serverless', 'requirements')
+
+  return BbPromise.each(runtimepaths, (runtimepath) => addTree(rootZip.folder(runtimepath), src))
+    .then(() => writeZip(rootZip, path.join('.serverless', 'pythonRequirementsLayer.zip')))
 }
 
 /**
  * Creates a layer on the serverless service for the requirements zip.
- * @return {Promise}
+ * @return {Promise} empty promise
  */
 function createLayers() {
-  this.serverless.service.layers['pythonRequirements'] = Object.assign(
-    {
+  this.serverless.service.layers['pythonRequirements'] = Object.assign({
       artifact: path.join('.serverless', 'pythonRequirements.zip'),
       name: `${this.serverless.service.stage}-python-requirements`,
-      description:
-        'Python requirements generated by serverless-python-requirements.'
+      description: 'Python requirements generated by serverless-python-requirements.'
     },
     this.options.layer
   );
@@ -46,8 +77,11 @@ function layerRequirements() {
   this.serverless.cli.log('Packaging Python Requirements Lambda Layer...');
 
   return BbPromise.bind(this)
+    .then(getRunTimeBuildPaths)
     .then(zipRequirements)
     .then(createLayers);
 }
 
-module.exports = { layerRequirements };
+module.exports = {
+  layerRequirements
+};