Docker commands and overview

Contents

• 1. Whats is docker and containers?
  • 1.1. Docker
    • 1.1.1. Advantages of Docker
  • 1.2. Container
• 2. Instalation in Windows 10
• 3. Docker commands
• 4. Dockerfile structure
• 5. Docker compose
  • 5.1. Commands Docker Compose
  • 5.2. Docker Compose template
• 6. Access Docker using REST API or Expose docker remotely
• 7. Docker images
  • 7.1. RabbitMQ (http://localhost:15672/)
  • 7.2. MsSql (localhost,1445)
  • 7.3. Jenkins
  • 7.4. Gitlab
  • 7.5. MongoDb
  • 7.6. Redis
  • 7.7. PostgreSql
• 8. Grafana
• 9. Graphite / Statds
• 10. Extras

1. Whats is docker and containers?

1.1. Docker

• Docker is an open platform for developing, shipping, and running applications.
• Docker provides to separate your applications from your infrastructure so you can deliver software quickly.
• Docker is a software development platform to deploy apps.
• Apps are packaged in containers that can be run on any OS.
• Apps run the same, regardless of where they're run:
  • Any machine.
  • No compatibility issues.
  • Predictable behavior.
  • Less work.
  • Easier to maintain and deploy.
  • Works with any language, any OS, any technology.
• Use cases: microservices architecture, lift-and-shift apps from on-premises to the AWS cloud, ...

1.1.1. Advantages of Docker

• Methodologies for shipping, testing, and deploying code quickly, you can significantly reduce the delay between writing code and running it in production.
• Docker provides for automating the deployment of applications as portable, self-sufficient containers that can run on the cloud or on-premises.
• Docker containers can run anywhere, in your local computer to the cloud.
• Docker image containers can run natively on Linux and Windows.

1.2. Container

• A container is a standard unit of software that packages up code and all its dependencies so, the application runs quickly and reliably from one computing environment to another.
• A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application.

2. Instalation in Windows 10

• Enable WSL in Windows 10
  • 
• Update wsl to wsl2
  • wsl --update

3. Docker commands

• All informations about docker in the machine
  • docker info
• Show the Docker version information
  • docker --version
• Create container by image
  • docker create --name <container_name> <image_name>
• Show running containers (Process status)
  • docker ps
  • docker ps -a # Show all
  • docker container ls -a
  • docker container ps -a
• List all images in local repository
  • docker images
• Pull (download) an image or a repository from a registry
  • docker pull <image_name>:<version> or <tag> # Example docker pull hello-world:latest
• Rum a command to start a container
  • docker start <container_name>
• Rum a command to stop a container
  • docker stop <container_name>
• Create and run the container, this command eliminates the need to run docker create and then docker start
  • docker run <image_name> # Example docker run hello-world
  • docker run -d <image_name> # -d Detach, run container in background and print container ID
  • docker run -d -p <external_port:internal_docker_port> <image_name> or <tag_name>
  • docker run -it --rm <image_name> # Run and delete the container when the container stops
• Remove image
  • docker image rm <image_name> or <image_id> # Example docker image rm hello-world:latest
• Remove container
  • docker container rm <container_name> or <container_id>
• Docker attach commands to start the container and peek at the output stream
  • docker attach --sig-proxy=false core-counter <container_name>
• Fetch the logs of a container
  • docker logs -f <image_name> # Log live
• Run a command in a running container
  • docker exec -it <container_name> bash # -it --interactive and --tty
  • docker exec -it -u root <container_name> bash # With user root
• Copy files/folders between a container and the local filesystem
  • docker cp <file_name> <container_name>:<path>/<file_name> # Example: docker cp script.sh myContainer:/tmp/script.sh
• Build Dockerfile
  • docker build .
  • docker build --tag <tag_name> .

4. Dockerfile structure

• FROM # Fully qualified Docker container image name

• COPY # Copy the specified folder on your computer to a folder in the container

• WORKDIR # Changes the current directory inside of the container to App

• ENTRYPOINT # Tells Docker to configure the container to run as an executable

• Example of Dockerfile example to build a dotnet project.

    FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build-env
  
    WORKDIR /my_custom_path_build_env
    COPY . ./
  
    # Run this command to see result of commands ls... docker build --no-cache --progress plain .
    RUN echo $(ls)
    RUN dotnet restore
    RUN dotnet publish -c Release -o publish
    RUN echo $(ls ./publish)
  
    FROM mcr.microsoft.com/dotnet/aspnet:7.0 AS stage-env
    WORKDIR /my_custom_path_stage_env
    COPY --from=build-env /my_custom_path_build_env/publish .
    RUN echo $(ls)
  
    EXPOSE 80
    ENTRYPOINT ["dotnet", "My.dll"]
  

5. Docker compose

5.1. Commands Docker Compose

• All informations about docker compose in the machine
  • docker-compose version
• Create/Recreate and start containers, use docker-compose.yml
  • docker-compose up -d
  • docker-compose up -d <name_service>
• Build or rebuild services
  • docker-compose build
  • docker-compose build <name_service> # Build specific image.
• Starts existing containers for a service.
  • docker-compose start
• Stop all containers
  • docker-compose stop
• Docker
  • compose-build
• Remove all containers and images

    docker-compose down
    docker rm -f $(docker ps -a -q)
    docker volume rm $(docker volume ls -q)
    docker rmi -f $(docker images -a -q)
  

5.2. Docker Compose template

version: '3'
services:
  my_service:
    container_name: CONTAINER_NAME
    image: IMAGE_NAME
    ports:
      - "8080:8080"
    volumes:
      - "$PWD/HOME:/VAR/PATH_HERE"
    networks:
      - net
networks:
  net:

6. Access Docker using REST API or Expose docker remotely

1. ps -ef | grep docker
2. sudo nano /lib/systemd/system/docker.service
3. Replace line ExecStart=*** to ExecStart=/usr/bin/dockerd -H fd:// -H=tcp://0.0.0.0:2375
4. sudo systemctl daemon-reload
5. sudo service docker restart
6. Test with url http://address:2375/images/json or http://address:2375/containers/json

7. Docker images

7.1. RabbitMQ (http://localhost:15672/)

• docker pull rabbitmq:3-management
• docker run -d -p 15672:15672 -p 5672:5672 --name rabbit_dev rabbitmq:3-management
• docker run -d -p 5672:5672 -p 15672:15672 --name rabbitmq_dev rabbitmq:3.9-management
• Default user and password: guest/guest

7.2. MsSql (localhost,1445)

• docker pull mcr.microsoft.com/mssql/server:2019-latest
• docker run -d -e "ACCEPT_EULA=Y" -e "SA_PASSWORD=yourStrong(!)Password" --name ordermssql -p 1445:1433 mcr.microsoft.com/mssql/server:2019-latest

7.3. Jenkins

• docker pull jenkins/jenkins
• docker run -p 8080:8080 jenkins/jenkins -- name jenkins_dev

7.4. Gitlab

• sudo docker exec -it gitlab_dev grep 'Password:' /etc/gitlab/initial_root_password
• sudo gitlab-rake "gitlab:password:reset[root]"

7.5. MongoDb

• docker pull mongo
• docker run -d -p 27017:27017 --name mongo_dev mongo
• docker exec -it mongo_dev bash

7.6. Redis

• docker pull redis
• docker run -d -p 6379:6379 --name redis_dev redis

7.7. PostgreSql

• docker run --name postgres_dev -p 5432:5432 -e POSTGRES_PASSWORD=mysecretpassword -d postgres

8. Grafana

• docker run -d --name=grafana -p 3000:3000 grafana/grafana

9. Graphite / Statds

• docker run -d --name graphite --restart=always -p 80:80 -p 2003-2004:2003-2004 -p 2023-2024:2023-2024 -p 8125:8125/udp -p 8126:8126 graphiteapp/graphite-statsd

10. Extras

• Specific command to dotnet applications
  • docker build -f API\Dockerfile . -t <image_name>
  • docker run -p 500:80 -t <image_name>
  • docker build --no-cache --progress plain .