A NodeJS app that generates sample data for KillrVideo and adds it to the site. Uses the Grpc clients for the KillrVideo microservices to call service methods and add sample data. Sample data is added on regular scheduled intervals. Will watch the status of the Grpc services and start/stop scheduled tasks based on the service availability.

This app is packaged and distributed as a Docker container. The typical usage is to download one of the KillrVideo microservice implementation projects, which contain configurations for starting the generator and infrastructure using docker-compose. For this reason, most users of KillrVideo won't need to clone this repo unless you need to modify the generator.

After cloning the repo, first install all dependencies and build the project:

> docker-compose run --no-deps -e NODE_ENV=development generator npm install
> docker-compose run --no-deps generator npm run build

If you have npm available locally, you may use it directly instead:

> npm install
> npm run build

All environment dependencies can be spun up using docker-compose (i.e. Etcd and DataStax Enterprise). You can start those dependencies with:

> docker-compose up -d

The app generates sample video data to insert into KillrVideo by searching YouTube for videos matching keywords specified in src/youtube/sources.js. Calling the YouTube Data API requires authentication, which for the generator is an API key. In order to run the generator from your local environment you will need to get an API key from the Google Developer Console.

Create a new project, select it, and expand APIs and Auth. In the list of APIs, enable YouTube Data API (v3) and under credentials select to create a new browser key. Now open the file docker-compose.yaml and add your API key:

services:
 generator:
   environment:
     KILLRVIDEO_YOUTUBE_API_KEY: <YOUR API KEY> 

There is a developer task included in the package.json scripts. You can run this task with:

> npm run watch

This will clean, do a build, and then watch and recompile source files on change. The main entrypoint for the app will be /dist/index.js after the build which you can start with or without a debugger attached. Source maps for the transpiled code are next to the output files in /dist.

If using VS Code for development, the tasks checked into the repo under /.vscode should allow you to start the program with debugging using F5.

By default docker-compose runs generator with debugger enabled and opens port 5858. You can use this to attach to the launched application to debug it.

To change behaviour of the application you can configure environment variables in docker-compose file. For example, you can configure the application to work with your own cassandra cluster instead of the 'built-in' dockerized one. Add the variable to a docker-compose file like here:

version: '3'
services:
  generator:
    ...
    environment:
      KILLRVIDEO_DSE_CONTACT_POINTS: 192.168.15.17

Logging Level       KILLRVIDEO_LOGGING_LEVEL          verbose
YouTube API Key     KILLRVIDEO_YOUTUBE_API_KEY        REPLACE_WITH_YOUR_KEY
Cassandra Host      KILLRVIDEO_DSE_CONTACT_POINTS     dse
Replication Factor  KILLRVIDEO_CASSANDRA_REPLICATION  "{ 'class' : 'SimpleStrategy', 'replication_factor' : 1 }"
Generator Keyspace  KILLRVIDEO_CASSANDRA_KEYSPACE     killrvideo_sample_data
Username            KILLRVIDEO_DSE_USERNAME           Null
Password            KILLRVIDEO_DSE_PASSWORD           Null

The app is released as a Docker image for use with the service project implementations. We try to follow semantic versioning and also to tag all releases in Git. To release, first version the project with npm by doing:

> npm version <specific_version | major | minor | patch | prerelease>

The postversion script will automatically push the newly created tag and any commits to the Git repository. The /scripts directory contains the scripts necessary to build/publish the Docker image.

We use Travis CI for doing continuous integration builds and it will use those scripts to automatically publish any tagged Git commits to Docker Hub. You can, of course, manually build and publish Docker images with those scripts as well.

Generator repeatedly logs error:

generator_1   | 2019-01-18T13:37:35.543Z - error:  Error: Bad Request
generator_1   |     at Request._callback (/opt/killrvideo-generator/node_modules/google-auth-library/lib/transporters.js:85:15)

The issue is ussually caused by unset youTubeApiKey. Check if you have set youTubeApiKey in config/local.yaml file and if it's still valid.

generator_1   | 2019-01-18T13:46:21.015Z - debug:  NoHostAvailableError: All host(s) tried for query failed. First host tried, 172.26.0.2:9042: Error: connect ECONNREFUSED 172.26.0.2:9042. See innerErrors.
...
generator_1   | 2019-01-18T13:46:21.018Z - verbose: Could not initialize Cassandra. Retry 1 in 10000ms.

Start up of DSE/Cassandra takes noticeable time, so this error happens every time if you launch generator and DSE at the same time. Usually it can be ignored, but if connection takes too long time, please check if dse container running and check its logs.