User postgres can't write to /var/lib/postgresql

[freshi]

The user postgres has no write privileges to it's own HOME directory /var/lib/postgresql.

ls -la /var/lib/postgresql/
total 12
drwxr-xr-x 3 root root 4096 Feb 24 10:45 .
drwxr-xr-x 42 root root 4096 Feb 24 10:45 ..
drwxr-xr-x 3 postgres postgres 4096 Feb 24 10:45 8.1

postgres@ubuntu:~$ touch ~/foo
touch: cannot touch `/var/lib/postgresql/foo': Permission denied

This problem occurs when you leaving psql, i.e.:

postgres@ubuntu:~$ psql template1
Welcome to psql 8.1.3, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
       \h for help with SQL commands
       \? for help with psql commands
       \g or terminate with semicolon to execute query
       \q to quit

template1=# \q
could not save history to file "/var/lib/postgresql/.psql_history": Permission denied
postgres@ubuntu:~$

[Martin Pitt (pitti)]

Hm, user postgres is not really meant to be an interactive user, but I'll fix that.

[Martin Pitt (pitti)]

 postgresql-common (43.1ubuntu2) dapper; urgency=low
 .
   * Merge changes from Debian branch (mainly robustness and test suite fixes).
   * t/020_create_sql_remove.t: Add check that SSL is automatically enabled on
     >= 8.0 clusters.
   * pg_createcluster: Improve SSL key access check to be more robust.
   * Enable taint checking in all programs and fix the resulting bugs.
   * PgCommon.pm: Replace backticks program calling with proper |- pipe opening
     to avoid intermediate shell and argument quoting problems.
   * testsuite: Only execute tests ending with .t.
   * Add t/100_upgrade_scripts.t: Test upgrade scripts.
   * run-upgrade-scripts:
     - Filter out the 'postgres' database on 8.1+ clusters.
     - Temporarily enable connections to databases which disable them.
     - Execute scripts in asciibetical order.
   * debian/postgresql-common.postinst: Ensure that /var/lib/postgresql is
     owned by postgres:postgres. (https://launchpad.net/bugs/32696)