tto / docs / k8s / docker

overview

container cannot run by itself, it always needs an image.

registry

create container registry in azure and copy login information

docker login user110acr.azurecr.io
# enter username and password

network

docker has three types of networks:

• bridge: NAT, the default network for docker containers uses 172.17.0.0/16. Container’s IPs are NATed to the host’s IP when accessing the network.
• macvlan: trunk port can transport multiple vlans, think multiple port 80 on a single host.
• overlay: for docker swarm which was obviated by kubernetes.

name resolution

containers in the same network can connect to each other by specifying the container name. the default network does not have name resolution.

always create a custom network and configure IPs that make sense in the environment.

volumes

creates persistent storage at /var/lib/docker/volumes/. Root permissions are required to access this path.

commands

# download inspect image
docker image pull ubuntu
docker image inspect ubuntu

# run container and detach (background) or -it (interactive)
docker container run -d 
docker container -it 

# --name sets the name of the container
# --hostname sets the hostname of the guest
docker container run -it --name ux --hostname ux-host ubuntu

# attach to a container with exec -it or attach
docker container exec -it ux /bin/bash
docker container attach ux

# install stuff in container and commit to new image
docker exec ux apt-get update && sudo apt-get install iputils-ping
docker container commit ux myux

# tag an image for upload and then push to azure registry
docker login user110acr.azurecr.io
docker image tag myuximage:latest user110acr.azurecr.io/myubuntu:latest
docker image push user110acr.azurecr.io/myubuntu

# build image from Dockerfile in current directory
docker build . -t myimage:latest