hasura-metrics-demo

Spring boot application that pulls metrics data from Hasura Pro Metrics Service and notifies a downstream client (eg. Slack, etc,.)

Pre-requisites

Access to a Hasura Pro Backend (LUX) service, especially the Metrics service URL and its admin-secret.
Slack App/Channel to post the error messages and User/Bot token to authenticate with the Slack API (Reference) having correct scopes.

Add the Hasura Metrics service Graphql API URl, Metrics servcie admin secret, Slack USer/Bot token and Slack channel/App id to application.properties file.
Build and run the Spring boot application.

The class ErrorFetchingService.java has the funtion that queries the metrics API to get the errors that occurred in the last 10 seconds.
The class ErrorNotificationJob.java has the scheduler that runs the above query every 10 seconds (Configurable in code). For Non empty responses , it calls the notify method in SlackNotifier.java to post the error to Slack.

The metrics service of LUX is itself a Hasura graphql engine and the Hasura console is exposed (by default) on port 8080 of the container/pod. The graphiql view of metrics service is self-documenting about the metrics exposed as graphql-apis. They can be consumed just like any other Graphql resources from other applications.
- An easy way to access the metrics service's console is to use kubectl port-forward (Reference). To map local port 8090 to port 8080 of the metrics pod (by default has name matching the wildcard metrics-*, for example metrics-54ffd6d96d-k5c6h), use kubectl port-forward metrics-54ffd6d96d-k5c6h 8090:8080 . Now the Hasura console for metrics is availble at http://localhost:8090 .