Docker & Kubernetes

01_DockerCLI.md

1. Create and Run a container: docker run -p <localhost port>:<docker container port> <image-name>
2. If you dont want console output: docker run -d <image-name>
3. List Running containers: docker ps
4. List all containers that have run: docker ps --all
5. Restart a stopped container: docker start <container-id>
6. Delete stopped containers and downloaded images: docker system prune
7. Stop a container: docker stop <container-id>
8. Execute additional commands in a running container (other than the starup command): docker exec -it <container-id> <command>
   Eg: docker exec -it <container-id> sh
9. Exit from a container: Ctrl + d or exit
10. Build a docker image from a Dockerfile in current directory: docker build -t <docker-id/project:version> .
11. While running a custom built docker image, we can drop the version to run the latest version: docker run <docker-id/project>
12. Dockerfile commands:

    FROM
    WORKDIR
    COPY
    RUN
    CMD
    EXPOSE # To inform user/ CICD the port to expose
    

13. Build using a dockerfile with custom name Dockerfile.dev: docker build -f Dockerfile.dev .
14. Mapping current working directory to a directory in the container: docker run -v $(pwd):/<directory in container> <image-name>
15. Mapping pwd without mapping an existing directory in the container: docker run -v <existing directory in container> -v $(pwd):/<directory in container> <image-name>
16. To prune all images, containers, networks and volumes that are not being used: docker system prune --volumes

02_Docker-Compose.md

1. Scripting DockerCLI commands and Starting up multiple containers with networking
2. Run the image defined in docker-compose.yml: docker-compose up
3. Rebuild the images defined in docker-compose.yml: docker-compose up --build
4. Run docker compose in the background: docker-compose up -d
5. Stop all containers started up by docker compose: docker-compose down
6. Docker will automatically restart stopped or crashed containers if we add a restart policy to that service: restart: <'no'/always(eg, for web apps)/on-failure(when exit code !=0, eg, for schedule jobs)/unless-stopped>
7. Docker compose ps (only from same working directory as docker-compose.yml): docker-compose ps

03_Kubernetes.md

1. Apply a config to kubernetes cluster: kubectl apply -f <config_file.yaml>
2. Get running pods: kubectl get pods
3. Describe any k8s object: kubectl describe <object-type> <object-name>
4. Use kind: Deployment instead of kind: Pod. Deployment is in apiVersion: apps/v1
5. Get running deployments: kubectl get deployments
6. Delete any k8s object: kubectl delete -f <config_file.yaml>
7. Updating a deployment to pull latest image: kubectl rollout restart -f <config_file.yaml>