Docker commands
Docker container
Running an image that exist on local machine
Start existing
# Start Docker Container
docker start <CONTAINER ID>
# Stop Running Docker Container
docker stop <CONTAINER ID>
# Delete Docker Container
docker rm <CONTAINER ID>
Start new
Run Docker Image in Docker Container
# -d switch is for detached process i.e command prompt is back
docker run -d <IMAGE NAME>
Check Running Containers
docker ps # shows running containers
docker ps --all # see all the running and exited containers
# List all containers, both running and stopped
sudo docker ps -a
sudo docker ps -aq #quiet
docker ps -l
# Cleaning
# Remove Containers
docker container rm 6d0806087e50
docker container rm 8cf7ae980534
docker system prune
Docker Logs and inspect
docker logs <container_id>
docker inspect <container_id>
Enter the Shell
Execute a command inside the shell of a container
-i -t flag Allows us to provide input to the container
docker exec -it
docker run --name redis-local redis # If the image is not there, then it will download
docker ps <id>
docker exec -it redis-local redis-cli
# Exit or Quit to come out of the prompt
one liner
# Start and run the shell inside busybox
docker run -it --name my-busybox busybox sh
# Start and existing container
docker start my-busybox #<busybox_id>
# Just execute the command and back to command prompt
docker exec -it my-busybox ls
Pass Environment Variables
docker run ceaf9e1ebef5 -e "SPRING_PROFILES_ACTIVE=dev" -e "server.port=8080"
docker run -d \
--name=mysql_learning \
--env="MYSQL_ROOT_PASSWORD=root" \
--env="MYSQL_PASSWORD=root" \
-v ~/Downloads/docker_data:/var/lib/mysql \
-p=3306:3306 \
mysql
docker exec -it mysql_learning mysql -uroot -proot
Docker Images
# List Docker Images on Computer
docker images -a
# Remove Docker Image
docker rmi <IMAGE ID>
#or
docker rmi -f <IMAGE ID>
#Remove All Docker Images on Computer
docker rmi $(docker images -f dangling=true)
# remove all the exited container
docker system prune
Docker build
Tagging an image
- the build command takes image name
- the run command takes container name
# Last parameter specifies the directory of files/folders to use for a build
docker build -t nitinkc/my-spring-boot-app:latest .
docker build -t my-spring-boot-app . #Without repo name
# Run the image from the docker hub
docker run -p 8080:8080 nitinkc/simpleweb
Publish Docker Image to Docker Hub
Summary (Docker hub images)
- Create Repository on https://hub.docker.com/ .
- Log into the Docker Hub from the command line
docker login --username=xxxxx --email=xxxxxor simplydocker login - Check the image ID (on local machine)using
docker images - Tag the image
docker tag <image-name> dockerhub-user-name/<repo-name>:tag-name - Push the image to the repository created
docker push dockerhub-user-name/<repo-name>
# Build the image using the Dockerfile in the project
docker build . --file Dockerfile --tag test-image
# Check the image created after the build
docker image ls
# Docker image
docker login
# Tag the image if not done while build
docker tag <CONTAINER ID> <DOCKER USERNAME>/<REPO>
docker tag test-image nitinkc/test-image
# Push the image
docker push nitinkc/test-image
# long form of the same command
docker image push nitinkc/test-image
Directory Binding
Bind a Directory in Docker Container to a Directory on Host Machine
The -v switch is used
-v
docker run -d \
--name=mysql_learning \
--env="MYSQL_ROOT_PASSWORD=root" \
--env="MYSQL_PASSWORD=root" \
-v ~/Downloads/docker_data:/var/lib/mysql \
-p=3306:3306 mysql
Docker Networks on Local Computer
docker network ls
#Create Custom Docker Bridge Network
docker network create --driver bridge <NETWORK NAME>
Run Docker container in the newly created custom bridge network
docker run <CONTAINER ID > --network <NAME OF CREATED NETWORK>
Avoid Port Binding
Make Docker Container use Host Network to Avoid Port Binding
docker run
--network host
Spring boot on Docker container running on port 5000, mapped with port 8080 of the local machine.
docker run --publish 8080:5000 -t nitinkc/todo-app:todo-backend-26
docker run -p 8080:5000 nitinkc/todo-app:todo-backend-26
docker run nitinkc/todo-app:todo-backend-26 --network host
Docker compose
Sample project for Docker Compose to build a Postgres DB and initialize with sample data
docker-compose up
docker-compose down
Dockerfile
#one CMD command (the last one always) executed per `Dockerfile`
# Use an existing docker image as a base
FROM openjdk:11
# Take the file from host machine into the container
# the dot (.) current directory w.r.t Dockerfile is located
# `/usr/src/myapp` : destination path inside the Docker image
COPY ./java_files /usr/src/myapp
# the absolute path set the working directory
WORKDIR /usr/src/myapp
RUN javac *.java
CMD ["java", "Main"]
Multistage Docker build
For a gradle project, where the build is done in stage 1 and is used in stage 2
#Build stage
FROM gradle:latest AS BUILD
WORKDIR /usr/app/
COPY ../microservices .
RUN gradle clean build
# Package stage
FROM openjdk:latest
ENV JAR_NAME=java-docker-experiments-1.0.jar
ENV APP_HOME=/usr/app/
WORKDIR $APP_HOME
COPY --from=BUILD $APP_HOME .
ENTRYPOINT exec java -jar $APP_HOME/build/libs/$JAR_NAME
Automate Docker push
The Automation can be done via circle-ci, github-work flow or any other automation engines
Gradle Project
Automatically publish image to dockerhub with github actions using dockerhub
The docker file takes care of compiling and generating the jar file Multistage Docker file
Check the version numebr increment in the git workflow docker-publish.yml file
Example of Github workflow
Maven Project
Maven Project with docker file
Simpler Version
Docker compose with SpringBoot
Project Readme
https://github.com/nitinkc/DockerConcepts/tree/master/6-dockerCompose-springboot-redis/visits#readme
The docker-compose file which uses the Dockerfile to build and execute the
Dockerfile