Docker swarm
- 1. Docker swarm @2020 copyright KalKey training
- 2. What is Docker Swarm? • Docker Swarm is an orchestration management tool that runs on Docker applications. It helps end-users in creating and deploying a cluster of Docker nodes. • Each node of a Docker Swarm is a Docker daemon, and all Docker daemons interact using the Docker API. • Each container within the Swarm can be deployed and accessed by nodes of the same cluster @2020 copyright KalKey training@2020 copyright KalKey training
- 3. How Does Docker Swarm Work? • In Swarm, containers are launched using services. A service is a group of containers of the same image that enables the scaling of applications. • A service is a description of a task or the state, whereas the actual task is the work that needs to be done. Docker enables a user to create services that can start tasks. • Before you can deploy a service in Docker Swarm, you must have at least one node deployed. • There are two types of nodes in Docker Swarm: Manager node. Maintains cluster management tasks Worker node. Receives and executes tasks from the manager node @2020 copyright KalKey training
- 4. Cont…. • The manager node knows the status of the worker nodes in a cluster, and the worker nodes accept tasks sent from the manager node. Every worker node has an agent that reports on the state of the node's tasks to the manager. This way, the manager node can maintain the desired state of the cluster. • The worker nodes communicate with the manager node using API over HTTP. In Docker Swarm, services can be deployed and accessed by any node of the same cluster. While creating a service, you'll have to specify which container image you're going to use. @2020 copyright KalKey training
- 5. Docker compose • Docker Compose is a tool for defining and running multi-container Docker applications. • If you have a need to define a service that requires more than one Docker container to function, Docker Compose might be the tool for you. • Docker Compose depends on the docker-compose.yml file @2020 copyright KalKey training
- 6. How Docker Compose works • Docker Compose builds a stack of applications to run a complete service. • The docker-compose.yml file is broken into sections, each section represents a single container which, when combined with the other containers, create the service. • For example, you could have a docker-compose.yml file that consists of two sections: web - the web server portion of the application. db - the database server portion of the application. • Each section can be comprised of different components. And because you might need to get quite specific with the web section, you could instruct docker-compose that the web portion will be defined in the Dockerfile @2020 copyright KalKey training
- 7. docker-compose.yml • This is a YAML file, so the formatting must be consistent. @2020 copyright KalKey training
- 8. DEMO @2020 copyright KalKey training