Pulp

ansible-pulp is installing postgresql 9.2 on centos 7 but django 2.1+ requires postgresql 9.4+:

https://docs.djangoproject.com/en/2.1/releases/2.1/#dropped-support-for-postgresql-9-3

We need to install a newer postgresql version via SCL.

If you try to use the pulp_ansible plugin on CentOS 7, you'll hit this error:

fatal: [pulp3-devel]: FAILED! => changed=true
  cmd:
  - /usr/local/lib/pulp/bin/django-admin
  - migrate
  - --no-input
  delta: '0:00:02.118012'
  end: '2019-07-16 18:05:26.170082'
  msg: non-zero return code
  rc: 1
  start: '2019-07-16 18:05:24.052070'
  stderr: |-
    Traceback (most recent call last):
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/utils.py", line 84, in _execute
        return self.cursor.execute(sql, params)
    psycopg2.errors.SyntaxError: syntax error at or near "WITH ORDINALITY"
    LINE 6:                     FROM unnest(c.conkey) WITH ORDINALITY co...
                                                      ^


    The above exception was the direct cause of the following exception:

    Traceback (most recent call last):
      File "/usr/local/lib/pulp/bin/django-admin", line 11, in <module>
        sys.exit(execute_from_command_line())
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
        utility.execute()
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/core/management/__init__.py", line 375, in execute
        self.fetch_command(subcommand).run_from_argv(self.argv)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/core/management/base.py", line 323, in run_from_argv
        self.execute(*args, **cmd_options)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/core/management/base.py", line 364, in execute
        output = self.handle(*args, **options)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/core/management/base.py", line 83, in wrapped
        res = handle_func(*args, **kwargs)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/core/management/commands/migrate.py", line 234, in handle
        fake_initial=fake_initial,
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/migrations/executor.py", line 117, in migrate
        state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
        state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/migrations/executor.py", line 245, in apply_migration
        state = migration.apply(state, schema_editor)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/migrations/migration.py", line 124, in apply
        operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/migrations/operations/models.py", line 372, in database_forwards
        to_field,
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/base/schema.py", line 535, in alter_field
        old_db_params, new_db_params, strict)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/postgresql/schema.py", line 124, in _alter_field
        new_db_params, strict,
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/base/schema.py", line 543, in _alter_field
        fk_names = self._constraint_names(model, [old_field.column], foreign_key=True)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/base/schema.py", line 1115, in _constraint_names
        constraints = self.connection.introspection.get_constraints(cursor, model._meta.db_table)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/postgresql/introspection.py", line 175, in get_constraints
        """, ["public", table_name])
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/utils.py", line 67, in execute
        return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/utils.py", line 76, in _execute_with_wrappers
        return executor(sql, params, many, context)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/utils.py", line 84, in _execute
        return self.cursor.execute(sql, params)
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/utils.py", line 89, in __exit__
        raise dj_exc_value.with_traceback(traceback) from exc_value
      File "/usr/local/lib/pulp/lib64/python3.6/site-packages/django/db/backends/utils.py", line 84, in _execute
        return self.cursor.execute(sql, params)
    django.db.utils.ProgrammingError: syntax error at or near "WITH ORDINALITY"
    LINE 6:                     FROM unnest(c.conkey) WITH ORDINALITY co...
                                                      ^
  stderr_lines: <omitted>
  stdout: |-
    Operations to perform:
      Apply all migrations: admin, ansible, auth, contenttypes, core, docker, file, sessions
    Running migrations:
      Applying admin.0001_initial... OK
      Applying admin.0002_logentry_remove_auto_add... OK
      Applying admin.0003_logentry_add_action_flag_choices... OK
      Applying core.0001_initial... OK
      Applying ansible.0001_initial... OK
      Applying ansible.0002_advanced_collections...
  stdout_lines: <omitted>