eventmaster

There are lots of events that happen in production such as deploys, service restarts, scale-up operations, etc. Right now these events happen, but we have no centralized place to track them -- which means we have no centralized place to search them. This project implements a service that:

• Creating an event store
• API for sending/firing events
• Potential integrations into other services for searching etc. (e.g. grafana annotations)
• Working with other pieces of infrastructure to expose meaningful events

Setup

Dependencies

• Go tool (tested at v1.16)
• Cassandra v3.10

Get Code

$ git clone \
    git@github.com:wish/eventmaster.git \
    $GOPATH/src/github.com/wish/eventmaster

Building

Dependencies are currently fetched using Go Modules. These are set up as dependencies to the default make target, so running:

make

will emit $GOPATH/bin/eventmaster after fetching and compiling dependencies.

Running

After running make eventmaster can be called directly:

$ $GOPATH/bin/eventmaster

Giving no flags eventmaster runs with sane option.

Configuration

Various aspects of eventmaster can be controlled through a collection of flags and options in a json config file. This will be consolidated when issue #32 is resolved.

The config provided in etc/eventmaster.json encodes the default values assumed by eventmaster if run without specifying a config file (-c). If these settings do not work for your service, please modify etc/eventmaster.json to specify values such as the addresses of the Cassandra cluster along with other database options.

Of note if "cassandra_config":"service_name" is non-empty then eventmaster currently uses discovery to find the IPs of the Cassandra cluster.

For example the port of the eventmaster server can be configured using the --port option, and if an alternate cassandra address needs to be specified adjust a eventmaster.json file and specify that it is used by providing the -c flag.

Open the eventmaster UI in your browser (default: http://localhost:50052). The UI can be used to create and query topics, data centers, and events.

To connect to a Cassandra database over TLS, several fields have to be set in the configration file. This includes:

• secured: Setting this field to true triggers TLS
• ca_path: The path to the CA cert file
• port: If different than default native protocol clients (port 9042)
• username
• password

Database Setup

Execute schema.cql on your Cassandra cluster. This will set up the event_master keyspace and event, temp_event, event_topic, and event_dc tables.

$ cqlsh -f schema.cql

The class and replication_factor can be modified as long as the consistency attribute is configured accordingly in the eventmaster.json used by eventmaster -c eventmaster.json.

Tests

Tests can be run (using the go tool) by calling:

$ make test

Adding annotations to a Grafana dashboard

This is documented in the documentation subdirectory

REST API

This is documented in the documentation subdirectory.