Pulling postgres:12 gets me postgres13.1 version

[mmojzis]

Hello,
I spent whole day debugging my Dockerfiles and docker-composes with issue that I needed postgres:12, but I was getting postgres13.1.
At the end I switched to postgres:12.5 and I got correct version.

[wglambert]

I'm not able to reproduce

$ docker pull postgres:12
12: Pulling from library/postgres
6ec7b7d162b2: Pull complete 
a7d6065bfd90: Pull complete 
1b99004acb42: Pull complete 
e11ab41f0489: Pull complete 
eaa59f6a7cf0: Pull complete 
e27743da9368: Pull complete 
10ffdd8ade29: Pull complete 
bdaa066489bc: Pull complete 
889684a529fa: Pull complete 
a89eb4df2d61: Pull complete 
053ae58e1489: Pull complete 
d2c54ffd195a: Pull complete 
9af5769854f9: Pull complete 
e4d297047587: Pull complete 
Digest: sha256:87eb6772b300b260f080eceb7658c39a37a6bd1e302f459305d2d4b5df3523b0
Status: Downloaded newer image for postgres:12

$ docker run -d --rm --name pg -e POSTGRES_PASSWORD=test postgres:12
06e016e5f573708fbb7ced25629ed5d08502e00145269309f300c3f404ffc1f5

$ docker exec -it pg psql -U postgres
psql (12.5 (Debian 12.5-1.pgdg100+1))
Type "help" for help.

postgres=# select version();
                                                     version                                                      
------------------------------------------------------------------------------------------------------------------
 PostgreSQL 12.5 (Debian 12.5-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
(1 row)

The 12 and 12.5 digests match exactly
https://hub.docker.com/_/postgres/?tab=tags&page=1&ordering=last_updated&name=12

[mmojzis]

Okay, well...I tried it on different server now and it works correctly...
But before on server I did docker system prune and had zero containers running so it was like fresh docker and then docker run -e POSTGRES_PASSWORD=password -it postgres:12 and postgres -V and I had PostgreSQL 13.1 Version there...So closing...Probably some kind of fu*kup on docker side...