Pass table and index names from serverless config to Lambda env

README.md

@@ -15,7 +15,7 @@ Original version (see [branch](https://github.com/epiphone/serverless-url-shorte
 - [ ] Integration tests: try running integration tests locally against `serverless-offline` and `serverless-dynamodb-local`
 - [x] ~~Smarter hourly time-series aggregation as opposed to the naive full-table scan~~
 - [ ] CI/CD: build, run tests and lint on GitHub actions + run `sls deploy` if on `master` branch
-- [ ] Set DynamoDB table names as Serverless Framework config variables and pass to Lambda handlers as env vars to avoid hardcoding table names to code
+- [x] ~~Set DynamoDB table names as Serverless Framework config variables and pass to Lambda handlers as env vars to avoid hardcoding table names to code~~
 - [ ] Tune the Lambda IAM policy to avoid overly wide permissions
 
 ## Dependencies

handler.ts

@@ -2,9 +2,8 @@ import { APIGatewayProxyHandler } from 'aws-lambda' // tslint:disable-line:no-im
 import * as AWS from 'aws-sdk'
 import * as shortId from 'shortid'
 
-// TODO use env vars:
-const URLS_TABLE = 'urls'
-const URL_INDEX = 'UrlIndex'
+const URLS_TABLE = process.env.URLS_TABLE_NAME!
+const URL_INDEX = process.env.URL_INDEX_NAME!
 
 const dynamoDb = process.env.IS_OFFLINE
   ? new AWS.DynamoDB.DocumentClient({

serverless.yml

@@ -2,6 +2,8 @@ service:
   name: url-shortener
 
 custom:
+  urls_table_name: urls
+  url_index_name: UrlIndex
   dynamodb:
     stages:
       - dev
@@ -20,6 +22,8 @@ provider:
     minimumCompressionSize: 1024 # Enable gzip compression for responses > 1 KB
   environment:
     AWS_NODEJS_CONNECTION_REUSE_ENABLED: 1
+    URLS_TABLE_NAME: ${self:custom.urls_table_name}
+    URL_INDEX_NAME: ${self:custom.url_index_name}
   iamRoleStatements:
     - Effect: Allow
       Action:
@@ -65,7 +69,7 @@ resources:
     urlsTable:
       Type: AWS::DynamoDB::Table
       Properties:
-        TableName: urls
+        TableName: ${self:custom.urls_table_name}
         AttributeDefinitions:
           - AttributeName: id
             AttributeType: S
@@ -78,7 +82,7 @@ resources:
           ReadCapacityUnits: 1
           WriteCapacityUnits: 1
         GlobalSecondaryIndexes:
-          - IndexName: UrlIndex
+          - IndexName: ${self:custom.url_index_name}
             KeySchema:
               - AttributeName: url
                 KeyType: HASH