How do I stop postgresql server inside container?

问题

I need to upgrade a postgresql database inside a running container. For that I need to stop the old server so I can start the new. The problem is that I didn't find how to stop the running postgres process thourgh systemctl, pg_ctl or service.

pg_ctl:

root@postgres-7ffd788bc9-g2dkv:/# su postgres
$ pg_ctl status
sh: 1: pg_ctl: not found

systemctl:

root@postgres-7ffd788bc9-g2dkv:/# systemctl status postgresql
bash: systemctl: command not found

service (returns nothing):

root@postgres-7ffd788bc9-g2dkv:/# service postgresql status
root@postgres-7ffd788bc9-g2dkv:/#

The postgresql was created using this kubernetes yaml:

    spec:
      containers:
        - name: postgres
          image: postgres:10.4

The server is running:

root@postgres-7ffd788bc9-g2dkv:/# psql postgresql://user:pass@127.0.0.1:5432/postgresdb
psql (12.5 (Debian 12.5-1.pgdg90+1), server 10.4 (Debian 10.4-2.pgdg90+1))
Type "help" for help.
postgresdb=# select VERSION();
                                                             version                                                              
----------------------------------------------------------------------------------------------------------------------------------
 PostgreSQL 10.4 (Debian 10.4-2.pgdg90+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516, 64-bit
(1 row)

What do you suggest to do?

回答1:

how about stopping the container, changing the version in the yaml then rebuild ?

回答2:

What I did at the end is creating a parallel postgres pod in Kubernetes which holds the new version. Then I dumped database from old server, copied it to the new server, and used it to initialize the data base there.

Here are the steps one by one:

Create a parallel postgres service with the new version
In old version pod:

pg_dumpall -U postgresadmin -h localhost -p 5432 > dumpall.sql

In the host:

kubectl cp postgres-old-pod:/dumpall.sql dumpall.sql
kubectl cp dumpall.sql postgres2-new-pod:/dumpall.sql

ssh to new-pod
extra step that I needed, becuase for some reason new pod didn't had 'postgres' user created: get into postgres client using your credentials:

psql postgresql://postgresadmin:pass1234@127.0.0.1:5432/postgresdb?sslmode=disable
postgresdb=# CREATE ROLE postgres LOGIN SUPERUSER PASSWORD 'somepassword123';

then exit postgres and exit to normal user

Finally update the database:

psql -U postgres -W -f dumpall.sql

来源：https://stackoverflow.com/questions/64855485/how-do-i-stop-postgresql-server-inside-container

标签

postgresql

Docker

Kubernetes