Maestro

Maestro is a component of the Kube Orchestra Project, a multi-cluster resources orchestrator for Kubernetes.

Maestro is the API for cluster registration and single-cluster resources definition.

There can be a question - why cannot the backend services (shown as Admin, gitops, REST Client etc in the drawing) talk to the MQTT Broker directly. While it definitely can, it may not be a good idea for the following reasons:

1. for security and other reasons it is good idea often not to allow MQTT Agents from the clusters and backend services to interact directly. Maestro gives that layer of separation.
2. considering that the MQTT agent may be offline for extended periods, it is customary for a shadow state of it to be maintained at the backend. This can handle the resync of the MQTT Agent when it comes back. Maestro allows that special application logic to be handled elegantly.

Kube Orchestra Architecture

Run

$ go install github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway
$ go install google.golang.org/protobuf/cmd/protoc-gen-go
$ go install google.golang.org/grpc/cmd/protoc-gen-go-grpc
$ go install github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-openapiv2
$ buf generate
$ go run cmd/server/main.go

Develop

Mosquitto

Mosquitto is an open-source MQTT broker

# Start mosquitto
make mosquitto-start

# Stop mosquitto
make mosquitto-stop

In order to connect to this Mosquitto server use user: admin, password: password, on port 1883. MQTT Explorer is a good client for local inspection and manipulation of the MQTT messages.

DynamoDB

# Start local DynamoDB
make dynamodb-start

# Read necessary env to be able to use `aws` CLI
source hack/dynamodb-local-env.sh

# List created tables
aws dynamodb list-tables

# Dump all resources
aws dynamodb scan --table-name Resources

Consumer

# Create a new Consumer
curl -X POST  localhost:8090/v1/consumers -H "Content-Type: application/json" -d '{"name": "Test", "labels": [{"key": "k1", "value": "v1" }]}'
{
  "id": "af467f701-f6af-408b-ba2f-9436896be890",
  "name": "Test",
  "labels": [
    {
      "key": "k1",
      "value": "v1"
    }
  ]
}

# And another one
curl -X POST  localhost:8090/v1/consumers -H "Content-Type: application/json" -d '{"name": "Test2", "labels": [{"key": "k1", "value": "v1" }]}'
{
  "id": "c497f701-f6af-408b-ba2f-9436896be537",
  "name": "Test",
  "labels": [
    {
      "key": "k1",
      "value": "v2"
    }
  ]
}

# Get a specific Consumer
curl localhost:8090/v1/consumers/c497f701-f6af-408b-ba2f-9436896be537 | jq
{
  "id": "c497f701-f6af-408b-ba2f-9436896be537",
  "name": "Test",
  "labels": [
    {
      "key": "k1",
      "value": "v2"
    }
  ]
}

Resource

# replace with the uuid of the target consumer
CONSUMER_ID="af467f701-f6af-408b-ba2f-9436896be890"

# create resource
curl -X POST localhost:8090/v1/consumers/$CONSUMER_ID/resources -H "Content-Type: application/json" --data-binary @examples/deployment.json
{
  "id": "a287fa52-924f-44e6-9101-5a35cc4af496",
  "consumerId": "303b9aa8-4980-41fd-8f97-339e4645f38c",
  "generationId": "1",
  "object": {
    "apiVersion": "apps/v1",
    "kind": "Deployment",
    ...
  },
  "status": null
}

# get resource
RESOURCE_ID="a287fa52-924f-44e6-9101-5a35cc4af496"
curl localhost:8090/v1/resources/$RESOURCE_ID

# update resource
curl -X PUT localhost:8090/v1/resources/$RESOURCE_ID -H "Content-Type: application/json" --data-binary @examples/deployment.v2.json

Integrating with ConcertMaster

# Get a Consumer ID
CONSUMER_ID=$(curl -s -X POST localhost:8090/v1/consumers|jq -r .id)

# From ConcertMaster's README
...
CONCERTMASTER_TOPIC_PREFIX=v1/ CONCERTMASTER_CLIENT_ID=$CONSUMER_ID go run ./cmd/concertmaster
...

# Create a resource
RESOURCE_ID=$(curl -s -X POST localhost:8090/v1/consumers/$CONSUMER_ID/resources -H "Content-Type: application/json" --data-binary @hack/example.deployment.json|jq -r .id)

# Update a resource
curl -X PUT localhost:8090/v1/resources/$RESOURCE_ID -H "Content-Type: application/json" --data-binary @hack/example.deployment.v2.json