'nfs-server' state in 'service_facts' differ from 'ansible.builtin.systemd' - service

Question

Running a CentOS 8 Stream server with nfs-utils version 2.3.3-57.el8 and using ansible-playbook core version 2.11.12 with a test playbook
- hosts: server-1
tasks:
- name: Collect status
service_facts:
register: services_state
- name: Print service_facts
debug:
var: services_state
- name: Collect systemd status
ansible.builtin.systemd:
name: "nfs-server"
register: sysd_service_state
- name: Print systemd state
debug:
var: sysd_service_state
will render the following results
service_facts
...
"nfs-server.service": {
"name": "nfs-server.service",
"source": "systemd",
"state": "stopped",
"status": "disabled"
},
...
ansible.builtin.systemd
...
"name": "nfs-server",
"status": {
"ActiveEnterTimestamp": "Tue 2022-10-04 10:03:17 UTC",
"ActiveEnterTimestampMonotonic": "7550614760",
"ActiveExitTimestamp": "Tue 2022-10-04 09:05:43 UTC",
"ActiveExitTimestampMonotonic": "4096596618",
"ActiveState": "active",
...
The NFS Server is very much running/active but the service_facts fails to report it as such.
Other services, such as httpd reports correct state in service_facts.
Have I misunderstood or done something wrong here? Or have I run in to an anomaly?

Answer 1

Running RHEL 7.9, nfs-utils 1.3.0-0.68.el7, ansible 2.9.27, I was able to observe the same behavior and to reproduce the issue you are observing.
It seems to be caused by "two" redundant service files (or the symlink).
ll /usr/lib/systemd/system/nfs*
...
-rw-r--r--. 1 root root 1044 Oct 1 2022 /usr/lib/systemd/system/nfs-server.service
lrwxrwxrwx. 1 root root 18 Oct 1 2022 /usr/lib/systemd/system/nfs.service -> nfs-server.service
...
diff /usr/lib/systemd/system/nfs.service /usr/lib/systemd/system/nfs-server.service; echo $?
0
Obviously a status request call to systemd will produce the expected result.
systemctl status nfs
● nfs-server.service - NFS server and services
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; enabled; vendor preset: disabled)
Drop-In: /run/systemd/generator/nfs-server.service.d
└─order-with-mounts.conf
Active: active (exited) since Sat 2022-10-01 22:00:00 CEST; 4 days ago
Process: 1080 ExecStartPost=/bin/sh -c if systemctl -q is-active gssproxy; then systemctl reload gssproxy ; fi (code=exited, status=0/SUCCESS)
Process: 1070 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
Process: 1065 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=0/SUCCESS)
Main PID: 1070 (code=exited, status=0/SUCCESS)
CGroup: /system.slice/nfs-server.service
systemctl status nfs-server
● nfs-server.service - NFS server and services
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; enabled; vendor preset: disabled)
Drop-In: /run/systemd/generator/nfs-server.service.d
└─order-with-mounts.conf
Active: active (exited) since Sat 2022-10-01 22:00:00 CEST; 4 days ago
Process: 1080 ExecStartPost=/bin/sh -c if systemctl -q is-active gssproxy; then systemctl reload gssproxy ; fi (code=exited, status=0/SUCCESS)
Process: 1070 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
Process: 1065 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=0/SUCCESS)
Main PID: 1070 (code=exited, status=0/SUCCESS)
CGroup: /system.slice/nfs-server.service
However, a test playbook
---
- hosts: nfs_server
become: true
gather_facts: false
tasks:
- name: Gather Service Facts
service_facts:
- name: Show Facts
debug:
var: ansible_facts
called via
sshpass -p ${PASSWORD} ansible-playbook --user ${ACCOUNT} --ask-pass service_facts.yml | grep -A4 nfs
will result into an output of
PLAY [nfs_server] ***************
TASK [Gather Service Facts] *****
ok: [test.example.com]
--
...
nfs-server.service:
name: nfs-server.service
source: systemd
state: stopped
status: enabled
...
nfs.service:
name: nfs.service
source: systemd
state: active
status: enabled
and report for the first service file found(?), nfs.service correct only.
Workaround
You could just check for ansible_facts.nfs.service, the alias name.
systemctl show nfs-server.service -p Names
Names=nfs-server.service nfs.service
Further Investigation
Ansible Issue #73215 "ansible_facts.service returns incorrect state"
Ansible Issue #67262 "service_facts does not return correct state for services"
It might be that this is somehow caused by What does status "active (exited)" mean for a systemd service? and def _list_rh(self, services) and even if there is already set RemainAfterExit=yes within the .service files.
systemctl list-units --no-pager --type service --all | grep nfs
nfs-config.service loaded inactive dead Preprocess NFS configuration
nfs-idmapd.service loaded active running NFSv4 ID-name mapping service
nfs-mountd.service loaded active running NFS Mount Daemon
● nfs-secure-server.service not-found inactive dead nfs-secure-server.service
nfs-server.service loaded active exited NFS server and services
nfs-utils.service loaded inactive dead NFS server and client services
For further tests
systemctl list-units --no-pager --type service --state=running
# versus
systemctl list-units --no-pager --type service --state=exited
one may also read about NFS server active (exited) and Service Active but (exited).
... please take note that I haven't done further investigation on the issue yet. Currently also for me it is still not fully clear which part in the code of ansible/modules/service_facts.py might causing this.