Postgres needs POSTGRES_PASSWORD at startup

[alfredo-f]

Expected Behavior

In the network section, container for Postgres should start up without any environment variables.

$ docker run --rm -d --name widgetdb --network skynet -p 5432 postgres
7f0248e3c0f4f03159ef966fd9767a4c7e3412801f8b0445cebb933d1e84e020
$ docker run --rm -d --name gadgetdb --network skynet -p 5432 postgres
8dc66701837c695728abb9046db71924112a9b8f2f1e096094ab5b5d631e2f73
$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                     NAMES
8dc66701837c        postgres            "docker-entrypoint..."   11 seconds ago      Up 10 seconds       0.0.0.0:32769->5432/tcp   gadgetdb
7f0248e3c0f4        postgres            "docker-entrypoint..."   40 seconds ago      Up 39 seconds       0.0.0.0:32768->5432/tcp   widgetdb
$

Current Behavior

The environment variable POSTGRES_PASSWORD must be specified at startup.

$ docker run --rm -d --name widgetdb --network skynet -p 5432 postgres
4f20eef0f61b876170ad92a1234370e251b8c3e508fc63eca6058240555e5930
$ docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                    PORTS               NAMES
4f20eef0f61b        postgres            "docker-entrypoint.s…"   3 seconds ago       Exited (1) 1 second ago                       gadgetdb
$ docker logs widgetdb 
Error: Database is uninitialized and superuser password is not specified.
       You must specify POSTGRES_PASSWORD to a non-empty value for the
       superuser. For example, "-e POSTGRES_PASSWORD=password" on "docker run".

       You may also use "POSTGRES_HOST_AUTH_METHOD=trust" to allow all
       connections without a password. This is *not* recommended.

       See PostgreSQL documentation about "trust":
       https://www.postgresql.org/docs/current/auth-trust.html
$

Possible Solution

$ docker run --rm -d -e POSTGRES_PASSWORD=strongpass --name widgetdb --network skynet -p 5432 postgres
f776a6e9c78d0103e7a0afd1ba16394b8b51a016fe7fd1a5b586de6304e383fa
$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                     NAMES
f776a6e9c78d        postgres            "docker-entrypoint.s…"   35 seconds ago      Up 33 seconds       0.0.0.0:32771->5432/tcp   widgetdb
$