Add README

Author: clareliguori

README.md

@@ -2,6 +2,33 @@
 
 Utilities and samples for building on CodeBuild
 
+### Sample App: Simple Calculator Service
+
+Simple Node.js Express-based web service that demonstrates continuous integration with AWS CodeBuild and continuous deployment with AWS CodeDeploy/CodePipeline.  This application was written for demo purposes only, and is definitely not production ready.
+
+### CI Tooling (Buildspecs)
+
+The buildspecs folder contains the following buildspec files for use with AWS CodeBuild:
+* build.yml: Basic npm-based build with unit tests and code coverage report.
+* shrinkwrap.yml: Upgrade npm dependencies and push an updated shrinkwrap file to source code repository.
+* sonarqube.yml: Run static code analysis against a SonarQube endpoint, with the endpoint and token stored in SSM Parameter Store.
+* build-test-suite-1.yml and build-test-suite-2.yml: Parallelize the unit tests into two separate projects.
+* environment.yml: Build a Docker image with cached npm dependencies
+* build-with-image-cache.yml: Use the cached npm dependencies from a custom Docker image.
+
+### CI Tooling (Glue)
+
+The ci_tools folder contains the following tools for use with AWS Lambda and Amazon CloudWatch Events to hook together the end-to-end CI process:
+* trigger_codebuild.js: Lambda function to start a CodeBuild build.
+* slack_notifications.js: Lambda function to post CodeBuild build notifications into a Slack channel.
+* cwe-rule-configuration/branch_ci.json: CloudWatch Events rule pattern to start a CodeBuild build for every push to the master branch of a CodeCommit repository.
+* cwe-rule-configuration/slack_event_pattern.json: CloudWatch Events rule pattern to notify Slack for failed CodeBuild builds.
+* cwe-rule-configuration/nightly_build_input.json: CloudWatch Events target input to start a CodeBuild build with a specific buildspec override and project name.
+
+### CD Tooling
+
+Contains an appspec.yml file and deploy_scripts folder for deploying the service with AWS CodeDeploy.
+
 ## License
 
-This library is licensed under the Apache 2.0 License. 
+This library is licensed under the Apache 2.0 License.