From 42d6c1799b3b1f9ea7605c4e426717ac76a4d533 Mon Sep 17 00:00:00 2001
From: Kevin Veen-Birkenbach <kevin@veen.world>
Date: Wed, 20 Aug 2025 12:45:19 +0200
Subject: [PATCH] sys-service: add systemd_directive filter and refactor
 service template

Introduced custom filter plugin to render optional systemd directives, refactored template to loop over directives, and adjusted default vars (TimeoutStartSec, RuntimeMaxSec handling).

Details: see ChatGPT conversation
https://chatgpt.com/share/68a5a730-6344-800f-b9a3-dc62d5902e9b
---
 .../filter_plugins/systemd_directive.py       | 17 +++++++++++++++++
 .../templates/systemctl.service.j2            | 19 +++++++++----------
 roles/sys-service/vars/main.yml               | 11 ++++++-----
 3 files changed, 32 insertions(+), 15 deletions(-)
 create mode 100644 roles/sys-service/filter_plugins/systemd_directive.py

diff --git a/roles/sys-service/filter_plugins/systemd_directive.py b/roles/sys-service/filter_plugins/systemd_directive.py
new file mode 100644
index 00000000..3a622731
--- /dev/null
+++ b/roles/sys-service/filter_plugins/systemd_directive.py
@@ -0,0 +1,17 @@
+def systemd_directive(value, key: str) -> str:
+    """
+    Render a single systemd directive line if value is non-empty.
+    Example: {{ myval | systemd_directive('ExecStart') }}
+    """
+    if value is None:
+        return ""
+    sval = str(value).strip()
+    if not sval:
+        return ""
+    return f"{key}={sval}"
+
+class FilterModule(object):
+    def filters(self):
+        return {
+            "systemd_directive": systemd_directive,
+        }
diff --git a/roles/sys-service/templates/systemctl.service.j2 b/roles/sys-service/templates/systemctl.service.j2
index 2b633a5b..3569e8e4 100644
--- a/roles/sys-service/templates/systemctl.service.j2
+++ b/roles/sys-service/templates/systemctl.service.j2
@@ -1,15 +1,14 @@
 [Unit]
 Description={{ SOFTWARE_NAME }} - Service for role '{{ system_service_id }}'
-{% if system_service_tpl_on_failure |length > 0 %}
-OnFailure={{ system_service_tpl_on_failure }}
-{% endif %}
+{{- system_service_tpl_on_failure | systemd_directive('OnFailure') }}
 
 [Service]
 Type={{ system_service_tpl_type }}
-{% if system_service_tpl_exec_start_pre |length > 0 %}
-ExecStartPre={{ system_service_tpl_exec_start_pre }}
-{% endif %}
-ExecStart={{ system_service_tpl_exec_start }}
-{% if system_service_tpl_runtime |length > 0 %}
-RuntimeMaxSec={{ system_service_tpl_runtime }}
-{% endif %}
+{%- for key, val in [
+  ('TimeoutStartSec', system_service_tpl_timeout_start_sec),
+  ('ExecStartPre',    system_service_tpl_exec_start_pre),
+  ('ExecStart',       system_service_tpl_exec_start),
+  ('RuntimeMaxSec',   system_service_tpl_runtime)
+] -%}
+{{- val | systemd_directive(key) }}
+{%- endfor %}
diff --git a/roles/sys-service/vars/main.yml b/roles/sys-service/vars/main.yml
index 2c64332c..b20f9a34 100644
--- a/roles/sys-service/vars/main.yml
+++ b/roles/sys-service/vars/main.yml
@@ -17,8 +17,9 @@ system_service_script_inter:   "/bin/{{ 'bash' if system_service_script_type ==
 system_service_script_exec:    "{{ system_service_script_inter }} {{ system_service_id | get_service_script_path( system_service_script_type ) }}"
 
 # Service template
-system_service_tpl_on_failure:      "{{ SYS_SERVICE_ON_FAILURE_COMPOSE }}"
-system_service_tpl_type:            "oneshot"
-system_service_tpl_exec_start:      "{{ system_service_script_exec }}"
-system_service_tpl_runtime:         "{{ SYS_SERVICE_DEFAULT_RUNTIME }}"
-system_service_tpl_exec_start_pre:  ""
\ No newline at end of file
+system_service_tpl_on_failure:        "{{ SYS_SERVICE_ON_FAILURE_COMPOSE }}"
+system_service_tpl_type:              "oneshot"
+system_service_tpl_exec_start:        "{{ system_service_script_exec }}"
+system_service_tpl_runtime:           "{{ '' if system_service_tpl_type == 'oneshot' else SYS_SERVICE_DEFAULT_RUNTIME }}"
+system_service_tpl_exec_start_pre:    ""
+system_service_tpl_timeout_start_sec: "60s"
\ No newline at end of file