metelitsaas / rabbitmq-hpa-k8s

RabbitMQ HorizontalPodAutoscaler Kubernetes

1. Description

Example of Kubernetes HorizontalPodAutoscaler, based on custom metrics from RabbitMQ REST API. Applications producer-app and consumer-app exchange messages through RabbitMQ Operator, the number of consumer-app replicas is controlled by queue length from rabbitmq-metric-server (Flask+uWSGI+NGINX).

2. Pipeline:

producer-app -> exchange(name=people_exchange, type=fanout) -> queue(name=people_queue) -> consumer-app(HPA, round-robin)

3. Components:

• rabbitmq
• rabbitmq-metric-server
• producer-application
• consumer-application

4. Installation

Run minikube

minikube start --vm-driver=virtualbox --cpus 2
minikube addons enable metrics-server
eval $(minikube docker-env)

Set namespace

kubectl apply -f kubernetes/dev-namespace.yaml

Deploy rabbitmq

# Install RabbitMQ Cluster Operator
kubectl apply -f https://github.com/rabbitmq/cluster-operator/releases/download/v1.3.0/cluster-operator.yml

# Encode base64 password for Secrets
echo -n dev_user | base64 # output: ZGV2X3VzZXI=
echo -n dev_pass | base64 # output: ZGV2X3Bhc3M=

# Create secrets of RabbitMQ
kubectl apply -f kubernetes/rabbitmq/rabbitmq-secret.yaml

# Encode sha256 password for ConfigMap
PWD_HEX=$(echo -n dev_pass | xxd -p)
SALT_HEX="AB99 73CD" 
HEX="$SALT_HEX $PWD_HEX"
SHA256=$(echo -n $HEX | xxd -r -p | shasum -a 256)
echo "$SALT_HEX $SHA256" | xxd -r -p | base64  # output: q5lzzTONASWgosGBd4yRY8au/Wsu4gjlrq6U/nPz1cBX1lDs

# Create ConfigMap of RabbitMQ
kubectl apply -f kubernetes/rabbitmq/rabbitmq-configmap.yaml

# Create RabbitMQ Instance
kubectl apply -f kubernetes/rabbitmq/rabbitmq-cluster.yaml

Deploy rabbitmq-metric-server

DOCKER_BUILDKIT=1 docker build \
    --tag rabbitmq-metric-server:1.0 \
    --file docker/rabbitmq-metric-server.dockerfile . 

# Generate TLS certificate and key
openssl req -newkey rsa:2048 -nodes -keyout nginx.key -x509 -days 365 -out nginx.crt

# Encode certificate and key by base64 
base64 nginx.crt
base64 nginx.key

# Create secrets of TLS NGINX
kubectl apply -f kubernetes/rabbitmq-metric-server/nginx-secret.yaml

# Create ConfigMap of NGINX configurations
kubectl apply -f kubernetes/rabbitmq-metric-server/nginx-configmap.yaml

# Create rabbitmq-metric-server deployment
kubectl apply -f kubernetes/rabbitmq-metric-server/rms-deployment.yaml

# Create rabbitmq-metric-server service
kubectl apply -f kubernetes/rabbitmq-metric-server/rms-service.yaml

# Create custom metrics API service
kubectl apply -f kubernetes/rabbitmq-metric-server/api-service.yaml

Deploy producer-app

DOCKER_BUILDKIT=1 docker build \
    --tag producer-app:1.2 \
    --file docker/producer-app.dockerfile .

kubectl apply -f kubernetes/producer-app/deployment.yaml

Deploy consumer-app

DOCKER_BUILDKIT=1 docker build \
    --tag consumer-app:1.3 \
    --file docker/consumer-app.dockerfile .

kubectl apply -f kubernetes/consumer-app/deployment.yaml
kubectl apply -f kubernetes/consumer-app/hpa.yaml