Jetstream mini-controller

A micro-controller for Nats Jetstream items.

This project is an alternative to the JetStream operator nack: https://github.com/nats-io/nack, built as a microservice.

It can create, update and delete Jetstream streams or Key-Value buckets based on some configuration provided in a file.

It doesn't require any CRD and uses a configmap to propagate the configuration to the watched file when deployed on a kubernetes cluster.

It can also work without kubernetes, by just deploying it and synchronizing the configuration file using another mean.

Example usage:

mvn clean install # Build, execute the tests, create the docker image and the helm chart.
mvn clean deploy # All of the above, and docker image publication to the configured registry.

# Install helm chart
# Using released chart
helm repo add jetstream-mini-controller https://AmadeusITGroup.github.io/jetstream-mini-controller
helm install jetstream-mini-controller/jetstream-mini-controller -f anyValues.yaml

# With local Build
helm install jetstream-mini-controller target/helm/jetstream-mini-controller-1.0-SNAPSHOT.tgz -f values.yaml 

Example values:

# service account needed to read the configmap
serviceAccountName: admin-user
# config map content
streams:
  - streamName: stream1
    subjects:
      - subject1
      - subject2
    storage: memory
    replicas: 1
    retention: limits
    maxAge: 60    
  - streamName: stream2
    subjects:
      - subject3
      - subject4
      - subject5
    storage: file
    replicas: 1
    retention: limits
    maxAge: 10  
  - streamName: stream3
    subjects:
      - subject6
      - subject7
    storage: memory
    replicas: 1
    retention: limits
    maxAge: 5
keyValues:
  - name: bucket1
    storage: memory
    replicas: 1
    maxHistoryPerKey: 15
    timeToLiveInSeconds: 60
  - name: bucket2
    storage: file
    replicas: 1
    maxHistoryPerKey: 1
    timeToLiveInSeconds: 600 
  - name: bucket3
    storage: memory
    replicas: 1
    maxHistoryPerKey: 5
    timeToLiveInSeconds: 30     

Streams configuration

Option	Description	Example value
streamName	Name of the stream	myStream
subjects	List of subjects to be included in the stream	- subject1.>
storage	Peristency type	file or memory
replicas	Replication factor	3
retention	Retention policy	limits
maxAge	Maximum retention time, in seconds	600

Key-Values configuration

Option	Description	Example value
name	Name of the key value bucket	muBucket
storage	Peristency type	file or memory
replicas	Replication factor	3
timeToLiveInSeconds	Maximum retention time, in seconds	600
maxHistoryPerKey	History to be kept per key in the bucket	3

Application configuration

The configuration uses standard quarkus one.

Configuration	Description	Default value
nats.url	Nats cluster URL(s)	nats://localhost:7656
config.fileName	Name of the file containing the stream configuration	stream-config.txt
config.mount.path	Configuration file path	/work/config
scheduler	Value to which the scheduler will be configured to wake up to and check the jetstream config.	30s

Other built-in features

As a standard quarkus application, this microservice includes:

• Readiness/liveness probes
• Prometheus metrics via micrometer
• Splunk log exporter (deactivated by default)