dotIN/docker-swarm-service-autoscaler

Scales the number of docker containers for service based on threshold(s) for metrics

Docker swarm service autoscaler

Scales the number of docker containers for service based on threshold(s) for metrics

Configuration

poll_interval_seconds: 60
metric_stores:
  - name: monitoring
    type: prometheus
    prometheus:
      url: http://localhost:9090
autoscale_rules:
  - service_name: example_web
    scale_min: 1
    scale_max: 3
    scale_step: 1
    metric_store: monitoring
    metric_query: scalar(avg(rate(http_requests_total{job="web"}[5m])))
    scale_up_threshold: 300
    scale_down_threshold: 200

Running

This service must be run on a docker swarm manager node if the connection to docker daemon needs to be established via /var/run/docker.sock

You can alternatively pass docker host url via DOCKER_HOST environment variable. You can pass environment variable DOCKER_TLS_VERIFY to verify the host against a CA certificate and DOCKER_CERT_PATH for specifying path to a directory containing TLS certificates to use when connecting to the Docker host.

Using code (local)

# Ensure python 2.x and pip installed
pip install -r app/requirements.txt
python -m app.main example/autoscaler.yml --log-level debug

Using docker

# Change example/autoscaler.yml as per your need
docker run -v /var/run/docker.sock:/var/run/docker.sock -v $(pwd)/example/autoscaler.yml:/etc/docker-swarm-service-autoscaler/autoscaler.yml sahajsoft/docker-swarm-service-autoscaler /etc/docker-swarm-service-autoscaler/autoscaler.yml --log-level=DEBUG

Running in docker swarm

services:
  autoscaler:
    image: sahajsoft/docker-swarm-service-autoscaler
    command: "/etc/docker-swarm-service-autoscaler/autoscaler.yml --log-leve=DEBUG"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    configs:
      - source: autoscaler.yml
        target: /etc/docker-swarm-service-autoscaler/autoscaler.yml
    deploy:
      placement:
        constraints:
          - node.role == manager

Example

Please checkout the examples here

Running tests

# Run tests
py.test
# Run tests and print coverage
py.test --cov=app
# Run tests and create html covergae report
py.test --cov=app --cov-report html
# Run tests automatically on any file change
ptw

Demo

Metric stores

• Prometheus (Supported)
• InfluxDB (Pending): #4

Contributing

Please raise an issue for feature requests & bugs. Please submit a pull request to contribute code