Simple way to realize green/blue deployment with traefik & docker-compose.
Schema of work:
- traefik proxies requests to containers and provide load balancer
- we have two versions of same container "green" and "blue" in one docker-compose.yaml and run only one of them in same time
When we deploy new version:
just run make blue or make green after make build
What is happen then?
- we starting opposite color container (blue or green it depends wich one already working)
- traefik load balancer split incoming traffic to both runned containers at this time
- stopping old container (docker sends terminate signal to it)
- container app state changing to "unhealthy" - and it returns error on /health endpoint
- traefik see unhealthy old container and remove it from traffik routing schema (but not closes already opened connections)
- app shutdown it http server (and wait opened connections)
- app closed and containers goes to stopped
- we remove old container
- everyone is happy, going to have smoothie
Firstly you should add hosts to your hosts file.
127.0.0.1 traefik.box ping.box
After that you will be able to see traefik panel on traefik.box.
Green state:
Blue deploy run.
make blueRolling update:
Blue state:
AB test due deploy:
ab -n 100000 -c 100 ping.box/ping
