This is WIP.

rumsimop: A K8S operator for simulating MQTT workloads

Quickstart

Install the CRD for simulation workloads into your cluster.

kubectl apply -f https://raw.githubusercontent.com/eickler/rumsimop/main/simulations.crd
kubectl get crd simulations.rumsim.io

Unfortunately, Github does not permit unauthenticated access to the Github Container Registry. Create a personal access token (classic) with the permission read:packages. Install the token as secret into your cluster to enable download of the images:

kubectl create secret docker-registry regcred --docker-server=ghcr.io --docker-username=GITHUB_USERNAME --docker-password=GITHUB_TOKEN

Install the operator into your K8S cluster (replace the values with the ones required for your MQTT installation):

helm repo add eickler-charts https://eickler.github.io/charts/
helm repo update
helm install \
  --set broker.url=mqtt://emqx-listeners:1883 \
  --set broker.user=mqtt \
  --set broker.pass=pass \
  rumsimop eickler-charts/rumsimop
kubectl get deployment rumsimop

Optionally, set

• otlp.collector to the URL of your OTLP collector and otlp.auth to the credentials for the collector.
• loglevel to the desired (Rust) log level, which will also be propagated to the simulator.

Run a workload:

kubectl create namespace mysimulation
kubectl apply -n mysimulation -f https://raw.githubusercontent.com/eickler/rumsimop/main/example_simulation.yaml

Check the workload:

kubectl get simulation -n mysimulation example-simulation
kubectl get statefulset -n mysimulation example-simulation
kubectl get secret -n mysimulation example-simulation
kubectl get pods -n mysimulation

Stop the workload:

kubectl delete simulation -n mysimulation example-simulation

Alternatively, run directly:

export BROKER_URL=<mqtt://localhost:1883>
export BROKER_USER=<mqtt>
export BROKER_PASS=<pass>
cargo run --bin rumsimop

Functionality

When you create a simulation, the operator

• Installs a secret with the broker credentials using the namespace and name of the simulation.
• Install a statefulset with the broker URL and all further parameters using the namespace and name of the simulation.
• The number of replicas in the statefulset will correspond to the requested workload. Currently, we assume that each pod can emit 100.000 MQTT messages per second (hardcoded).
• You can enable OTLP tracing and metrics on the operator and the pods by setting
  • OTLP_COLLECTOR: URL of the OTLP collector.
  • OTLP_AUTH: Authentication string for the OTLP collector.
• You can choose a version of the simulator to be used by setting RUMSIM_VERSION (default "latest").

Known issues

Next steps

• Agree with myself to use either OTLP_ENDPOINT or OTLP_COLLECTOR.
• Test if multiple simulations can run concurrently (i.e. client ID, device IDs, does this work?)
• There is still a duplicate build on release, one for the PR merge of the release-please branch and one for the release itself. The first one should not be triggered. (Does not harm though.)
• Add test cases
• Check/fix running multiple operators in the same cluster (i.e. multiple MQTT destinations).
• Improve docs.