docker/README.md

docker

Setup

curl -fsSL https://get.docker.com -o get-docker.sh
sh get-docker.sh
docker run hello-world

Alphine

source https://wiki.alpinelinux.org/wiki/Docker

apk add docker
addgroup username docker
rc-update add docker default
service docker start

fuse overlay

apt install --yes fuse-overlayfs

Containers

Containers list

docker container list

Interactive shell

#example with ubuntu
docker container run -it ubuntu /bin/bash

Remove when finished

#example with ubuntu
docker container run -rm ubuntu

Attach to a running container

#attach to stdout of container with name ubuntu
docker container run -a ubuntu
## connects to container with name ubuntu and attach to bash (interactive)
docker exec -it pm_wp_adminer /bin/bash

Volumes

Export / Backup

#export volumes (tar) from dbstore container into volume
docker run --rm --volumes-from dbstore -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /dbdata

Import / Restores

#inports volumes (untar) into dbstore2
docker run --rm --volumes-from dbstore2 -v $(pwd):/backup ubuntu bash -c "cd /dbdata && tar xvf /backup/backup.tar --strip 1"

NFS

Notes:

docker-compose.yaml

volumes:
  volume00:
    driver: local
    driver_opts:
      type: ${VOLUME_TYPE}
      o: ${VOLUME_O}
      device: "${VOLUME_DEVICE}"

.env

VOLUME_TYPE="nfs"

# DNS server ip, RW:read and write
VOLUME_O="addr=10.10.1.1,rw" 

# Folder on NFS Server
## Must exists on nfs server, or security errors when starting container 
VOLUME_DEVICE=":/export/docker-volumes/volume00" 

Network

Macvlan

Create

How to create a docker macvlan network

# run on host
docker network create -d macvlan --subnet=192.168.1.249/24 --gateway=192.168.1.1  -o parent=eth0 macvlan_network

Host comunication

if network required between host and docker container on a macvlan docker network

• Option 1 - Create another macvlan on host

  • Setup vars

    MACVLAN_NAME=macvlan_bridge
    HOST_ETHERNET_ADP=eth0
    NETWORK=192.168.1.0/24
    

  • Create mavclan adapter

    ip link add $MACVLAN_NAME link $HOST_ETHERNET_ADP type macvlan mode bridge  
    ip addr add $NETWORK dev $MACVLAN_NAME  
    ifconfig $MACVLAN_NAME up  
    

  • Add routing

    ip route add $CONTAINER_MAVLAN_IP dev $MACVLAN_NAME
    

  • Delete mavclan adapter

    ifconfig $MACVLAN_NAME down
    ip link del $MACVLAN_NAME 
    

  • Persisting macvlan configuration Example:

    • network: 192.168.1.0/24
    • macvlan name:: macvlan_bridge
    • macvlan static ip: 192.168.1.240/32
    • docker containers on macvlan networks:
      • 192.168.1.254
      • 192.168.1.253
      • 192.168.1.250
      • 192.168.1.248

    # create/edit /etc/network/interfaces.d/macvlan_bridge
    iface macvlan_bridge inet manual
        pre-up ip link add macvlan_bridge link eth0 type macvlan mode bridge
        pre-up ip addr add 192.168.1.240/32 dev macvlan_bridge
        up ip link set macvlan_bridge up
        post-up ip route add 192.168.1.254 dev macvlan_bridge
        post-up ip route add 192.168.1.253 dev macvlan_bridge
        post-up ip route add 192.168.1.252 dev macvlan_bridge
        post-up ip route add 192.168.1.250 dev macvlan_bridge
        post-up ip route add 192.168.1.248 dev macvlan_bridge
    

log

write to docker log buffer

echo "Hello World!" >> /proc/1/fd/1

clear all docker logs

truncate -s 0 /var/lib/docker/containers/*/*-json.log;

delete all images

docker rmi -f $(docker images -aq)

delete all images

docker volume rm $(docker volume ls -qf dangling=true)