Added 'subnetGroup' option (#65)

README.md

@@ -112,6 +112,13 @@ custom:
     services:
       - kms
       - secretsmanager
+
+    # optional
+    # can pick one of subnet groups in (rds / redshift / elasticache / dax)
+    # By default, if not specified, all of the subnet groups will be created.
+    # ex) DAX is not available in ap-northeast-2 so I don't want to make DAX subnet group
+    subnetGroups:
+      - rds
 ```
 
 ## CloudFormation Outputs

__tests__/subnet_groups.test.js

@@ -3,9 +3,12 @@ const {
   buildElastiCacheSubnetGroup,
   buildRedshiftSubnetGroup,
   buildDAXSubnetGroup,
+  buildSubnetGroups,
 } = require('../src/subnet_groups');
 
 describe('subnet_groups', () => {
+  let subnetGroupList = {};
+
   describe('#buildRDSSubnetGroup', () => {
     it('skips building an RDS subnet group with no zones', () => {
       const actual = buildRDSSubnetGroup();
@@ -35,6 +38,7 @@ describe('subnet_groups', () => {
           },
         },
       };
+      subnetGroupList.rds = expected;
       const actual = buildRDSSubnetGroup(2);
       expect(actual).toEqual(expected);
       expect.assertions(1);
@@ -99,6 +103,7 @@ describe('subnet_groups', () => {
           },
         },
       };
+      subnetGroupList.elasticache = expected;
       const actual = buildElastiCacheSubnetGroup(2);
       expect(actual).toEqual(expected);
       expect.assertions(1);
@@ -160,6 +165,7 @@ describe('subnet_groups', () => {
           },
         },
       };
+      subnetGroupList.redshift = expected;
       const actual = buildRedshiftSubnetGroup(2);
       expect(actual).toEqual(expected);
       expect.assertions(1);
@@ -221,6 +227,7 @@ describe('subnet_groups', () => {
           },
         },
       };
+      subnetGroupList.dax = expected;
       const actual = buildDAXSubnetGroup(2);
       expect(actual).toEqual(expected);
       expect.assertions(1);
@@ -255,4 +262,26 @@ describe('subnet_groups', () => {
       expect.assertions(1);
     });
   });
+
+  describe('#buildSubnetGroups', () => {
+    it('no subnetGroups option', () => {
+      const expected = Object.keys(subnetGroupList).reduce(
+        (acc, key) => Object.assign(acc, subnetGroupList[key]),
+        {},
+      );
+      const actual = buildSubnetGroups(2, []);
+      expect(actual).toEqual(expected);
+      expect.assertions(1);
+    });
+    it('get specific subnetGroups option', () => {
+      const getSubnetGroupsOptions = ['rds', 'redshift'];
+      const expected = getSubnetGroupsOptions.reduce(
+        (acc, key) => Object.assign(acc, subnetGroupList[key]),
+        {},
+      );
+      const actual = buildSubnetGroups(2, getSubnetGroupsOptions);
+      expect(actual).toEqual(expected);
+      expect.assertions(1);
+    });
+  });
 });

src/index.js

@@ -8,7 +8,7 @@ const {
   buildLambdaSecurityGroup,
 } = require('./vpc');
 const { buildAppNetworkAcl, buildPublicNetworkAcl, buildDBNetworkAcl } = require('./nacl');
-const { buildSubnetGroups } = require('./subnet_groups');
+const { buildSubnetGroups, validSubnetGroups } = require('./subnet_groups');
 const { buildEndpointServices, buildLambdaVPCEndpointSecurityGroup } = require('./vpce');
 const { buildLogBucket, buildLogBucketPolicy, buildVpcFlowLogs } = require('./flow_logs');
 const { buildBastion } = require('./bastion');
@@ -38,6 +38,7 @@ class ServerlessVpcPlugin {
     let createNatInstance = false;
     let createBastionHost = false;
     let bastionHostKeyName = null;
+    let subnetGroups = [];
 
     const { vpcConfig } = this.serverless.service.custom;
 
@@ -70,6 +71,9 @@ class ServerlessVpcPlugin {
       if (Array.isArray(vpcConfig.services)) {
         services = vpcConfig.services.map(s => s.trim().toLowerCase());
       }
+      if (Array.isArray(vpcConfig.subnetGroups) && vpcConfig.subnetGroups.length > 0) {
+        ({ subnetGroups } = vpcConfig);
+      }
 
       if ('createDbSubnet' in vpcConfig && typeof vpcConfig.createDbSubnet === 'boolean') {
         ({ createDbSubnet } = vpcConfig);
@@ -222,7 +226,16 @@ class ServerlessVpcPlugin {
       if (numZones < 2) {
         this.serverless.cli.log('WARNING: less than 2 AZs; skipping subnet group provisioning');
       } else {
-        Object.assign(resources, buildSubnetGroups(numZones));
+        for (let i = 0; i < subnetGroups.length; i += 1) {
+          const subnetGrp = subnetGroups[i];
+          if (validSubnetGroups.indexOf(subnetGrp) === -1) {
+            throw new this.serverless.classes.Error(
+              `WARNING: '${subnetGrp}' is invalid subnetGroups option.
+    you should input among these options: ['rds', 'redshift', 'elasticache', 'dax']`,
+            );
+          }
+        }
+        Object.assign(resources, buildSubnetGroups(numZones, subnetGroups));
       }
     }
 

src/subnet_groups.js

@@ -1,5 +1,7 @@
 const { DB_SUBNET } = require('./constants');
 
+const validSubnetGroups = ['rds', 'redshift', 'elasticache', 'dax'];
+
 /**
  * Build an RDSubnetGroup for a given number of zones
  *
@@ -133,12 +135,27 @@ function buildDAXSubnetGroup(numZones = 0, { name = 'DAXSubnetGroup' } = {}) {
  * Build the database subnet groups
  *
  * @param {Number} numZones Number of availability zones
+ * @param {Array} subnetGroups options of subnet groups
  * @return {Object}
  */
-function buildSubnetGroups(numZones = 0) {
+function buildSubnetGroups(numZones = 0, subnetGroups = []) {
   if (numZones < 2) {
     return {};
   }
+  const subnetGroupList = {
+    rds: buildRDSSubnetGroup,
+    redshift: buildRedshiftSubnetGroup,
+    elasticache: buildElastiCacheSubnetGroup,
+    dax: buildDAXSubnetGroup,
+  };
+  function assembleSubnetGrp(acc, service) {
+    const builtSubnetGroup = subnetGroupList[service.toLowerCase()](numZones);
+    return Object.assign(acc, builtSubnetGroup);
+  }
+
+  if (subnetGroups.length > 0) {
+    return subnetGroups.reduce(assembleSubnetGrp, {});
+  }
   return Object.assign(
     {},
     buildRDSSubnetGroup(numZones),
@@ -154,4 +171,5 @@ module.exports = {
   buildRDSSubnetGroup,
   buildRedshiftSubnetGroup,
   buildSubnetGroups,
+  validSubnetGroups,
 };