Running containers in the background:
To run a container in the background, you can use the -d option with the docker run command. This will run the container in detached mode, where it runs in the background and doesn’t receive input or display output.
For example, to run a simple Python application in a container in the background, you can use the following commands:
- Create a Dockerfile with the following content:
FROM python:3
WORKDIR /app
COPY . .
CMD ["python", "app.py"]
- Build the Docker image with the following command:
docker build -t my-python-app .
- Run the container in the background with the following command:
docker run -d -p 5000:5000 my-python-app
This will run the container in the background, mapping port 5000 in the container to port 5000 on the host.
Source: How to “Dockerize” Your Python Applications | Docker
Streaming container logs:
To stream the logs of a container, you can use the docker logs command with the -f option. This will follow the logs of the container and display them in real-time.
For example, to stream the logs of the Python application container created in the previous example, you can use the following command:
docker logs -f my-python-app
This will display the logs of the container as they are generated.
Source: How to “Dockerize” Your Python Applications | Docker
Managing Docker services for distributed applications:
To manage Docker services for distributed applications, you can use Docker Swarm. Docker Swarm is a container orchestration tool that allows you to deploy and manage containers on a cluster of machines.
To create a Docker Swarm, you can use the docker swarm init command. This will initialize a new swarm on the current machine.
Once the swarm is created, you can use the docker service create command to deploy a service to the swarm. This will create a new service and deploy it to the swarm, automatically scheduling it on the available nodes.
For example, to deploy the Python application service to the swarm, you can use the following commands:
- Create a new service with the following command:
docker service create --name my-python-app --publish 5000:5000 my-python-app
- List the services in the swarm with the following command:
docker service ls
- Inspect the service with the following command:
docker service inspect my-python-app
This will show the details of the service, including the tasks and nodes it is running on.
Source: Get started with Kubernetes (using Python) | Kubernetes
Working with Docker Compose for multi-container application setups:
To work with Docker Compose for multi-container application setups, you can use the docker-compose command. Docker Compose is a tool for defining and running multi-container applications.
To use Docker Compose, you need to create a docker-compose.yml file with the configuration of your application. This file should contain the services, networks, and volumes of your application.
For example, to create a docker-compose.yml file for the Python application, you can use the following content:
version: '3'
services:
app:
build: .
ports:
- "5000:5000"
This file defines a single service called app, which is built from the Dockerfile in the current directory and maps port 5000 in the container to port 5000 on the host.
Once the docker-compose.yml file is created, you can use the docker-compose command to manage your application.
For example, to start the application, you can use the following command:
docker-compose up
This will start the application and display the logs in real-time.
To stop the application, you can use the following command:
docker-compose down
This will stop the application and remove the containers, networks, and volumes.
Source: Docker Compose Tutorial: advanced Docker made simple | Educative.io
Additional resources:
