memory_tracker is not disabled in unstack.sh

[Nobuhiro MIKI]

It appears that memory_tracker does not depend on dstat in stack.sh and depends on dstat in unstack.sh.
So, because of the asymmetry, if memory_tracker is used without dstat, it is ignored by unstack.sh.

Below are the steps to reproduce.
I tried with Ubuntu20.04 and devstack master branch (commit: fd502fe0527f).

$ cat > local.conf <<'EOF'
[[local|localrc]]
ENABLED_SERVICES=memory_tracker
ADMIN_PASSWORD=nomoresecret
DATABASE_PASSWORD=stackdb
RABBIT_PASSWORD=stackqueue
SERVICE_PASSWORD=$ADMIN_PASSWORD
LOGFILE=$DEST/logs/stack.sh.log
EOF

$ ./stack.sh
$ ./unstack.sh
$ systemctl status devstack@*.service

[Nobuhiro MIKI (nmiki)]

I sent the patch for this bug.
https://review.opendev.org/c/openstack/devstack/+/865237

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/devstack/+/865237
Committed: https://opendev.org/openstack/devstack/commit/0572d73f8561f3304f897bf9ee2f63c406cc21b7
Submitter: "Zuul (22348)"
Branch: master

commit 0572d73f8561f3304f897bf9ee2f63c406cc21b7
Author: Nobuhiro MIKI <email address hidden>
Date: Wed Feb 22 10:38:49 2023 +0900

    Disable memory_tracker and file_tracker in unstask.sh properly

    stop_dstat() calls stop_process() for dstat, memory_tracker and
    file_tracker respectively. Inside stop_process(), a check for the
    existence of the service is performed by is_service_enabled().

    So even if we apply this seemingly dangerous commit,
    is_service_enabled() is respected, so it's safe.

    Closes-Bug: #1998990
    Change-Id: Ica58cdb1d60c4c796f582d82ed2cde0be94b1a7e
    Signed-off-by: Nobuhiro MIKI <email address hidden>