#aws #container #docker

App are packaged in containers and can be run on any OS Docker is a software development platform to deploy apps Use cases: Micro-service, lift and shift app from on-premise machine to cloud. ![[Drawing 2023-02-09 22.29.59.excalidraw|600x400]]

Flow

Dockerfile => build => Docker image => push/pull <=> ECR

Docker container managements in AWS

  1. ECS (Amazon’s own container platform)
  2. Fargate (Amazon’s own Serverless container platform) (ECS & EKS)
  3. EKS (Amazon’s managed Kubernetes)
  4. ECR

VM and Docker containers

![[Drawing 2023-02-09 22.37.50.excalidraw |600x400]]

Docker components

  • Docker daemon. Usually installed with docker dep.
  • Docker engine provider (by native Docker engine, Podman, Colima) to start the docker daemon and connect to host via Docker.sock. When install it on the remote server, consider docker-ce

    Best practices for building & creating Docker image

  • Use multi stage build to reduce the image size. In the Dockerfile, for e.g we can define multiple of FROM command, a part of Dockerfile is for building and part of Dockerfile is for running script at the minimum dependencies and configurations.
  • Use Dockerignore to minimize the files relevant to the build step.
  • Minimize the dependencies to reduce the build time and image size
  • Decouple the applications into multiple containers
  • Leverage build cache to make the Docker build faster
    • Utilize the local/external build cache (s3, Github build cache)
    • Consider to cleanup the build cache by interval by using docker prune (image/build)
  • Fix version for the Docker image deps

Dockerfile instructions

Instruction Purposes
FROM target the base image for the Dockerfile
ADD add file from host to the container
COPY copy file from host to the container
ENTRYPOINT can be used as default executor of the Dockerfile
CMD can be used as default executor of the Dockerfile. But it can be used to be fed as an input of the ENTRYPOINT
RUN run the command when building the Docker image
VOLUME mounted volumes from host or other container to the current Docker container
EXPOSE export a port to the host environment