General Commands
- Execute command every second:
- Use
watch to repeat a command at intervals.
- Example:
watch -n 1 <command>
- List containers every second:
watch -n 1 docker container ls
Swarm Management
- Check Swarm Status:
- Verify if running in swarm mode:
docker system info (check "Swarm" status: active/inactive)- Filter for Swarm:
docker system info | grep Swarm
- Initialize Swarm:
- Start a swarm cluster:
docker swarm init
- Stop Swarm:
- Shut down the cluster (run on leader manager):
docker swarm leave --force
- Generate Join Tokens:
- For workers:
docker swarm join-token worker
- For managers:
docker swarm join-token manager
Nodes
- List Nodes:
- View all nodes in the swarm:
docker node ls
- Inspect Node:
- Get details of a specific node:
docker node inspect <node id>
- Remove Node:
- Delete a node from the swarm:
docker node rm <node id>
- Promote Worker:
- Elevate a worker to manager:
docker node promote <worker id>
- Demote Manager:
- Revert a manager to worker:
docker node demote <manager id>
Services
- List Services:
- View all services in the swarm:
docker service ls
- Create Service:
- Launch a new service with specified parameters:
- Syntax:
docker service create --name <service name> -p <source port>:<container port> --replicas <desired count> <image name>
- Example:
docker service create --name httpd -p 9090:80 --replicas 5 httpd
- Parameters:
-name: Service namep: Publish port (host:container)-replicas: Number of container instances
- Inspect Service:
- Get detailed information:
docker service inspect <service name>
- Example:
docker service inspect httpd
- List Service Containers:
- View containers created by a service:
docker service ps <service name>
- Example:
docker service ps httpd
- Remove Service:
- Delete a service:
docker service rm <service name>
- Example:
docker service rm httpd
- Scale Service:
- Adjust the number of containers:
- Syntax:
docker service scale <service name>=<new desired count>
- Example:
docker service scale httpd=5