DOCKER KEEPALIVED

Keepalived manage virtual ip between servers. Containers health can be checked to keep the virtual ip on the node.

Pre-requisites

Kernel module : ip_vs on the nodes - modprob ip_vs

Available Versions

• 1.2 (docker tags: 1.2, latest) : works only on docker host debian jessie and ubuntu trusty
• 1.2-dockerinside (docker tags: 1.2-dockerinside-1.10, 1.2-dockerinside-1.11)

Environment variables

• VIRTUAL_IP: VIP, by default 192.168.254.254/32
• VIRTUAL_ROUTER_ID: must be the same in all nodes
• INTERFACE: interface to set virtual IP
• PRIORITY: 101 on master, 100 on backups
• PASSWORD: Need the same on all nodes
• CONTAINERS_TO_CHECK: containers name list to check health, separated by single space
• CHECK_FALL: require X failures for KO
• CHECK_RISE: require X successes for OK
• CHECK_CREATION: if true, please define the $SWARM_ADDR, $SWARM_CERTS and $CHECK_HEALTH_IMAGE
• CHECK_HEALTH_IMAGE: if $CHECK_CREATION, image to use to create a container every $CHECK_INTERVAL
• SWARM_ADDR: default to 127.0.0.1:4000
• SWARM_CERTS: The path to Swarm certificats (ca.pem, cert.pem, key.pem), by default /root/.docker/
• CHECK_INTERVAL: Check health of $CONTAINERS_TO_CHECK,$CHECK_CREATION) every $CHECK_INTERVAL seconds, by default 5s
• ENABLE_LB: Enable Load balancer config, if true, please define $REAL_IP, $REAL_PORTS, $LB_ALGO and $LB_KIND
• VIRTUAL_IP_LB: IP for LB; This IP will be shared by all the nodes, by default 192.168.254.253/32
• REAL_IP: Real address of the Backend Nodes separated by single space
• REAL_PORTS: Real ports exposed on hosts separated by single space to LoadBalancing
• LB_ALGO: LoadBalancing Algotythm
• LB_KIND: LoadBalancing Method

Usage

Without docker inside

docker run -d --name keepalived --restart=always --net=host --cap-add=NET_ADMIN \
    -e VIRTUAL_IP='1.1.1.1' \
    -e VIRTUAL_ROUTER_ID='51' \
    -e INTERFACE='eth0' \
    -e PRIORITY='100' \
    -e PASSWORD=topsecret \
    -e CONTAINERS_TO_CHECK="container_name_1 container_name_2" \
    -e CHECK_FALL='1' \
    -e CHECK_RISE='1' \
    -e CHECK_CREATION='true' \
    -e CHECK_HEALTH_IMAGE='alpine' \
    -e SWARM_ADDR='127.0.0.1:4000' \
    -e SWARM_CERTS='/root/.docker/' \
    -e CHECK_INTERVAL='7' \
    -e ENABLE_LB='true' \
    -e VIRTUAL_IP_LB='1.1.1.2' \
    -e REAL_IP="1.1.1.30 1.1.1.31 1.1.1.32" \
    -e REAL_PORTS='80 443' \
    -e LB_ALGO='lblcr' \
    -e LB_KIND='DR' \
    -v /var/run/docker.sock:/var/run/docker.sock \
    -v /usr/bin/docker:/usr/bin/docker \
    -v /usr/lib/x86_64-linux-gnu/:/usr/lib/x86_64-linux-gnu/:ro \
    -v /lib/x86_64-linux-gnu:/lib/x86_64-linux-gnu \
    -v /root/.docker:/root/.docker \
    alterway/keepalived:1.2

With docker inside

docker run -d --name keepalived --restart=always --net=host --cap-add=NET_ADMIN \
    -e VIRTUAL_IP='1.1.1.1' \
    -e VIRTUAL_ROUTER_ID='51' \
    -e INTERFACE='eth0' \
    -e PRIORITY='100' \
    -e PASSWORD=topsecret \
    -e CONTAINERS_TO_CHECK="container_name_1 container_name_2" \
    -e CHECK_FALL='1' \
    -e CHECK_RISE='1' \
    -e CHECK_CREATION='true' \
    -e CHECK_HEALTH_IMAGE='alpine' \
    -e SWARM_ADDR='127.0.0.1:4000' \
    -e SWARM_CERTS='/root/.docker/' \
    -e CHECK_INTERVAL='7' \
    -e ENABLE_LB='true' \
    -e VIRTUAL_IP_LB='1.1.1.2' \
    -e REAL_IP="1.1.1.30 1.1.1.31 1.1.1.32" \
    -e REAL_PORTS='80 443' \
    -e LB_ALGO='lblcr' \
    -e LB_KIND='DR' \
    -v /var/run/docker.sock:/var/run/docker.sock \
    -v /root/.docker:/root/.docker \
    alterway/keepalived:1.2

Contributors

• Nicolas Berthe
• Ophélie Mauger

License

View LICENSE for the software contained in this image.