Strange volume naming issue

[behnsen]

Hello, today I simply tried to setup the easy example from postgres on docker hub:

docker run --name some-postgres -e POSTGRES_PASSWORD=mysecretpassword -d postgres

For my purposes I added a publish and a volume flag:

docker run --name some-postgres -v financial-data:/var/lib/postgresql/data -p 5432:5432 -e POSTGRES_PASSWORD=mysecretpassword -d postgres

With the usage of the volume name financial-data, the container is running normally, but the connection to postgres with psql -h 127.0.0.1 -U postgres from Host failes:

Password for user postgres: psql: error: could not connect to server: FATAL: password authentication failed for user "postgres"

I played around with different parameters, but the problem fits exactly this name. For the volume names financialdata, financial_data, test-data everything works like expected:

Password for user postgres:
psql (12.2 (Ubuntu 12.2-4), server 12.3 (Debian 12.3-1.pgdg100+1)) Type "help" for help.`

postgres=# \q

I investigated the container a little bit more with docker exec -it some-postgres bash and found the problem in the hash for the user postgres in the database. For all volume names I get the following table:

postgres=# SELECT rolname, rolpassword from pg_authid;

    rolname          |             rolpassword             

    postgres         |              md5f669773c3bc40401c00685cf2f9c4ca2

Only for the volume name financial-data the hash is different:

postgres=# SELECT rolname, rolpassword from pg_authid;

      rolname          |             rolpassword             

      postgres          |            md5b6dc5d7640bc808bd106517d65780bd4

Additional informations:

docker version: 19.03.8, build afacb8b7f0 postgres version: 12.3 (Debian 12.3-1.pgdg100+1) host: Ubuntu 20.04

Can anyone confirm this issue?

[wglambert]

I can't reproduce

[Postgres 2] -> [Host:5432] -> [Postgres 1]

$ docker volume create financial-data
financial-data

$ docker run --name some-postgres -v financial-data:/var/lib/postgresql/data -p 5432:5432 -e POSTGRES_PASSWORD=mysecretpassword -d postgres
0ad7d3b80b36ff57683f153f5d79e6eba4c851ea41f24fb54515e4a86dea0ecf

$ docker run -it --rm postgres psql -h 172.17.0.1 -U postgres
Password for user postgres: 
psql (12.3 (Debian 12.3-1.pgdg100+1))
Type "help" for help.

postgres=# SELECT rolname, rolpassword from pg_authid;
          rolname          |             rolpassword             
---------------------------+-------------------------------------
 pg_monitor                | 
 pg_read_all_settings      | 
 pg_read_all_stats         | 
 pg_stat_scan_tables       | 
 pg_read_server_files      | 
 pg_write_server_files     | 
 pg_execute_server_program | 
 pg_signal_backend         | 
 postgres                  | md5f669773c3bc40401c00685cf2f9c4ca2
(9 rows)

[behnsen]

Thanks. Maybe there was something broken in my volume. Because you created the volume explicitly and not on the run like I am, I removed the old image and created it new. Now, everything works fine. Sorry for not checking consistency of the volume before. Can be closed.