From 3210a94ef9615367d16feb82e1dec4e55f549869 Mon Sep 17 00:00:00 2001
From: Mariusz Nowak <mariusz@medikoo.com>
Date: Fri, 20 Dec 2019 13:47:29 +0100
Subject: [PATCH] fix(AWS Lambda): Workaround AWS issue related to alias
 redeployments

Addresses #7059
---
 lib/plugins/aws/lib/naming.js                 |  9 +++
 .../aws/package/compile/functions/index.js    | 77 +++++++++++++++++++
 2 files changed, 86 insertions(+)

diff --git a/lib/plugins/aws/lib/naming.js b/lib/plugins/aws/lib/naming.js
index 6a37087d9..77b0f0d59 100644
--- a/lib/plugins/aws/lib/naming.js
+++ b/lib/plugins/aws/lib/naming.js
@@ -163,6 +163,15 @@ module.exports = {
       ''
     )}`;
   },
+  getCodeDeployApplicationLogicalId() {
+    return 'CodeDeployApplication';
+  },
+  getCodeDeployDeploymentGroupLogicalId() {
+    return 'CodeDeployDeploymentGroup';
+  },
+  getCodeDeployRoleLogicalId() {
+    return 'CodeDeployRole';
+  },
   getLambdaProvisionedConcurrencyAliasLogicalId(functionName) {
     return `${this.getNormalizedFunctionName(functionName)}ProvConcLambdaAlias`;
   },
diff --git a/lib/plugins/aws/package/compile/functions/index.js b/lib/plugins/aws/package/compile/functions/index.js
index bdad7d6ff..9fcf3f779 100644
--- a/lib/plugins/aws/package/compile/functions/index.js
+++ b/lib/plugins/aws/package/compile/functions/index.js
@@ -542,6 +542,83 @@ class AwsCompileFunctions {
         cfTemplate.Resources[
           this.provider.naming.getLambdaProvisionedConcurrencyAliasLogicalId(functionName)
         ] = aliasResource;
+
+        // Note: Following setup is a temporary workaround for a known AWS issue of
+        // "Alias with weights can not be used with Provisioned Concurrency" error being
+        // thrown when switching version for same alias which has provisioned concurrency configured
+        // AWS works currently on a fix, and we were informed it'll be released in the near future
+
+        const codeDeployApplicationLogicalId = this.provider.naming.getCodeDeployApplicationLogicalId();
+        const codeDeployDeploymentGroupLogicalId = this.provider.naming.getCodeDeployDeploymentGroupLogicalId();
+        aliasResource.UpdatePolicy = {
+          CodeDeployLambdaAliasUpdate: {
+            ApplicationName: { Ref: codeDeployApplicationLogicalId },
+            DeploymentGroupName: { Ref: codeDeployDeploymentGroupLogicalId },
+          },
+        };
+        if (!cfTemplate.Resources[codeDeployApplicationLogicalId]) {
+          const codeDeployApplicationResource = {
+            Type: 'AWS::CodeDeploy::Application',
+            Properties: {
+              ComputePlatform: 'Lambda',
+            },
+          };
+          const codeDeployDeploymentGroupResource = {
+            Type: 'AWS::CodeDeploy::DeploymentGroup',
+            Properties: {
+              ApplicationName: { Ref: codeDeployApplicationLogicalId },
+              AutoRollbackConfiguration: {
+                Enabled: true,
+                Events: [
+                  'DEPLOYMENT_FAILURE',
+                  'DEPLOYMENT_STOP_ON_ALARM',
+                  'DEPLOYMENT_STOP_ON_REQUEST',
+                ],
+              },
+              DeploymentConfigName: {
+                'Fn::Sub': ['CodeDeployDefault.Lambda${ConfigName}', { ConfigName: 'AllAtOnce' }],
+              },
+              DeploymentStyle: {
+                DeploymentType: 'BLUE_GREEN',
+                DeploymentOption: 'WITH_TRAFFIC_CONTROL',
+              },
+            },
+          };
+          Object.assign(cfTemplate.Resources, {
+            [codeDeployApplicationLogicalId]: codeDeployApplicationResource,
+            [codeDeployDeploymentGroupLogicalId]: codeDeployDeploymentGroupResource,
+          });
+
+          if (this.serverless.service.provider.cfnRole) {
+            codeDeployDeploymentGroupResource.Properties.ServiceRoleArn = this.serverless.service.provider.cfnRole;
+          } else {
+            const codeDeployRoleLogicalId = this.provider.naming.getCodeDeployRoleLogicalId();
+            const codeDeployRoleResource = {
+              Type: 'AWS::IAM::Role',
+              Properties: {
+                ManagedPolicyArns: [
+                  'arn:aws:iam::aws:policy/service-role/AWSCodeDeployRoleForLambda',
+                ],
+                AssumeRolePolicyDocument: {
+                  Version: '2012-10-17',
+                  Statement: [
+                    {
+                      Action: ['sts:AssumeRole'],
+                      Effect: 'Allow',
+                      Principal: {
+                        Service: ['codedeploy.amazonaws.com'],
+                      },
+                    },
+                  ],
+                },
+              },
+            };
+            codeDeployDeploymentGroupResource.Properties.ServiceRoleArn = {
+              'Fn::GetAtt': [codeDeployRoleLogicalId, 'Arn'],
+            };
+            cfTemplate.Resources[codeDeployRoleLogicalId] = codeDeployRoleResource;
+          }
+        }
       });
     });
   }