patroni postgres test

amalgamation of a variety of example docker-compose deploys for local patroni testing:

• https://github.com/zalando/patroni
• https://github.com/assisken/patroni-consul-docker
• https://github.com/digitalis-io/postgresql-consul-demo

for further reference:

• https://github.com/zalando/spilo
• https://github.com/zalando-stups/stups-etcd-cluster

what is happening?

• the demo-app polls haproxy on port 5432 to check connectivity to the active/primary db
• haproxy is configured to route requests to the 3 patroni instances, using the patroni managed rest api port 8008 to health check status. only the active/primary db will return a 2xx response and requests will route there.
• patroni will sync with consul cluster and register/deregister themselves as needed to ensure only 1 node is tagged with master

what to expect

Run the following to launch the project

docker-compose up

Eventually, you will see output similar to:

test failover

Kill the patroni-1 container to force a failover (assuming patroni-1 is the master/primary)

docker-compose stop patroni-1