Postgres shuts down immediately when started with docker-compose

Question

Postgres shuts down immediately when started with docker-compose. The yaml file used is below

version: '2'

services:   
    postgres:
        image: postgres:9.5
        container_name: local-postgres9.5
        ports:
          - "5432:5432"

The log when docker-compose up command is executed

Creating local-postgres9.5
Attaching to local-postgres9.5
local-postgres9.5 | The files belonging to this database system will be owned by user "postgres".
local-postgres9.5 | This user must also own the server process.
local-postgres9.5 |
local-postgres9.5 | The database cluster will be initialized with locale "en_US.utf8".
local-postgres9.5 | The default database encoding has accordingly been set to "UTF8".
local-postgres9.5 | The default text search configuration will be set to "english".
local-postgres9.5 |
local-postgres9.5 | Data page checksums are disabled.
local-postgres9.5 |
local-postgres9.5 | fixing permissions on existing directory /var/lib/postgresql/data ... ok
local-postgres9.5 | creating subdirectories ... ok
local-postgres9.5 | selecting default max_connections ... 100
local-postgres9.5 | selecting default shared_buffers ... 128MB
local-postgres9.5 | selecting dynamic shared memory implementation ... posix
local-postgres9.5 | creating configuration files ... ok
local-postgres9.5 | creating template1 database in /var/lib/postgresql/data/base/1 ... ok
local-postgres9.5 | initializing pg_authid ... ok
local-postgres9.5 | initializing dependencies ... ok
local-postgres9.5 | creating system views ... ok
local-postgres9.5 | loading system objects' descriptions ... ok
local-postgres9.5 | creating collations ... ok
local-postgres9.5 | creating conversions ... ok
local-postgres9.5 | creating dictionaries ... ok
local-postgres9.5 | setting privileges on built-in objects ... ok
local-postgres9.5 | creating information schema ... ok
local-postgres9.5 | loading PL/pgSQL server-side language ... ok
local-postgres9.5 | vacuuming database template1 ... ok
local-postgres9.5 | copying template1 to template0 ... ok
local-postgres9.5 | copying template1 to postgres ... ok
local-postgres9.5 | syncing data to disk ... ok
local-postgres9.5 |
local-postgres9.5 | WARNING: enabling "trust" authentication for local connections
local-postgres9.5 | You can change this by editing pg_hba.conf or using the option -A, or
local-postgres9.5 | --auth-local and --auth-host, the next time you run initdb.
local-postgres9.5 |
local-postgres9.5 | Success. You can now start the database server using:
local-postgres9.5 |
local-postgres9.5 |     pg_ctl -D /var/lib/postgresql/data -l logfile start
local-postgres9.5 |
local-postgres9.5 | ****************************************************
local-postgres9.5 | WARNING: No password has been set for the database.
local-postgres9.5 |          This will allow anyone with access to the
local-postgres9.5 |          Postgres port to access your database. In
local-postgres9.5 |          Docker's default configuration, this is
local-postgres9.5 |          effectively any other container on the same
local-postgres9.5 |          system.
local-postgres9.5 |
local-postgres9.5 |          Use "-e POSTGRES_PASSWORD=password" to set
local-postgres9.5 |          it in "docker run".
local-postgres9.5 | ****************************************************
local-postgres9.5 | waiting for server to start....LOG:  database system was shut down at 2016-05-16 16:51:54 UTC
local-postgres9.5 | LOG:  MultiXact member wraparound protections are now enabled
local-postgres9.5 | LOG:  database system is ready to accept connections
local-postgres9.5 | LOG:  autovacuum launcher started
local-postgres9.5 |  done
local-postgres9.5 | server started
local-postgres9.5 | ALTER ROLE
local-postgres9.5 |
local-postgres9.5 |
local-postgres9.5 | /docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*
local-postgres9.5 |
local-postgres9.5 | LOG:  received fast shutdown request
local-postgres9.5 | LOG:  aborting any active transactions
local-postgres9.5 | LOG:  autovacuum launcher shutting down
local-postgres9.5 | LOG:  shutting down
local-postgres9.5 | waiting for server to shut down....LOG:  database system is shut down
local-postgres9.5 |  done
local-postgres9.5 | server stopped
local-postgres9.5 |
local-postgres9.5 | PostgreSQL init process complete; ready for start up.
local-postgres9.5 |
local-postgres9.5 | LOG:  database system was shut down at 2016-05-16 16:51:55 UTC
local-postgres9.5 | LOG:  MultiXact member wraparound protections are now enabled
local-postgres9.5 | LOG:  database system is ready to accept connections
local-postgres9.5 | LOG:  autovacuum launcher started

Postgres seems to work fine when a container is started using the same image with docker run

docker run --name local-postgres9.5 -p 5432:5432 postgres:9.5

Answer 1

If you look at your log output, the following lines appear towards the end:

local-postgres9.5 | server stopped
local-postgres9.5 |
local-postgres9.5 | PostgreSQL init process complete; ready for start up.

Apparently, stopping and restarting the Postgres server is part of the initialisation process. In fact, the second-to-last line says

local-postgres9.5 | LOG:  database system is ready to accept connections.