docker-compose up

They have removed links from version 2 onwards, added feature depends_on

Looking at networks: how easy and innovative way

Container share the underlying OS kernel and as a result we cannot have a windows container running on linux host or vice versa.

$ docker run -d \

--name devtest \

--mount source=myvol2,target=/app \

  nginx:latest

$ docker run -d \
 --name devtest \
 -v myvol2:/app \
  nginx:latest
$ docker service ps devtest-service
$ docker run -d \
 --name=nginxtest \
 --mount source=nginx-vol,destination=/usr/share/nginx/html \
  nginx:latest
$ docker run -d \
 --name=nginxtest \
 --mount source=nginx-vol,destination=/usr/share/nginx/html,readonly \
  nginx:latest

Tip #1: Order matters for caching

Tip #2: More specific COPY to limit cache busts

Tip #3: Identify cacheable units such as apt-get update & install

Reduce Image size

Image size can be important because smaller images equal faster deployments and a smaller attack surface.

Tip #4: Remove unnecessary dependencies

.

Tip #5: Remove package manager cache

Maintainability

Tip #6: Use official images when possible

Tip #7: Use more specific tags

Tip #8: Look for minimal flavors

Reproducibility

Tip #9: Build from source in a consistent environment

The source code is the source of truth from which you want to build a Docker image. The Dockerfile is simply the blueprint.

Tip #10: Fetch dependencies in a separate step

.Tip #11: Use multi-stage builds to remove build dependencies (recommended Dockerfile)

$ cat ./get-data.sh

docker exec mysql-db mysql -pdb_pass123 -e 'use foo; select * from myTable'

docker run --name alpine-2 --network=none alpine

docker network create --driver bridge --subnet 182.18.0.1/24 --gateway 182.18.0.1 wp-mysql-network

docker run -d --name mysql-db --network wp-mysql-network -e MYSQL_ROOT_PASSWORD=db_pass123  mysql:5.6

docker run --network=wp-mysql-network -e DB_Host=mysql-db -e DB_Password=db_pass123 -p 38080:8080 --name webapp --link mysql-db:mysql-db -d kodekloud/simple-webapp-mysql

docker run --network=wp-mysql-network -e DB_Host=mysql-db -e DB_Password=db_pass123 -p 38080:8080 --name webapp --link mysql-db:mysql-db -d kodekloud/simple-webapp-mysql

docker run -d kodekloud/simple-webapp --name blue-app -e APP_COLOR=blue -p 38282:8080

docker run --name mysql-db -e MYSQL_ROOT_PASSWORD=db_pass123 -d mysql

docker run -d -e MYSQL_ROOT_PASSWORD=db_pass123 --name mysql-db mysql