From f886e9afebd6462414966157c8c89ec0934667c4 Mon Sep 17 00:00:00 2001
From: Adam Goldsmith <adam@adamgoldsmith.name>
Date: Tue, 29 Nov 2022 17:54:54 -0500
Subject: [PATCH] Automatically generate Icinga2 CheckCommand conf

---
 check_home_assistant_state.conf | 45 ----------------------------
 check_home_assistant_state.py   | 52 +++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 45 deletions(-)
 delete mode 100644 check_home_assistant_state.conf

diff --git a/check_home_assistant_state.conf b/check_home_assistant_state.conf
deleted file mode 100644
index 959b4af..0000000
--- a/check_home_assistant_state.conf
+++ /dev/null
@@ -1,45 +0,0 @@
-object CheckCommand "home_assistant_state" {
-  command = [ PluginContribDir + "/check_home_assistant_state/check_home_assistant_state.py" ]
-  arguments = {
-    "--token" = {
-      value = "$home_assistant_state_token$"
-      description = "API token for Home Assistant"
-    }
-    "--url" = {
-      value = "$home_assistant_state_url$"
-      description = "URL for Home Assistant"
-    }
-    "--device-class" = {
-      value = "$home_assistant_state_device_class$"
-      description = "Device class of entities to monitor"
-    }
-    "--warning" = {
-      value = "$home_assistant_state_warning$"
-      description = "Return warning if battery percentage is outside RANGE"
-    }
-    "--critical" = {
-      value = "$home_assistant_state_critical$"
-      description = "Return critical if battery percentage is outside RANGE"
-    }
-    "--min" = {
-      value = "$home_assistant_state_min$"
-      description = "Min for performance data"
-    }
-    "--max" = {
-      value = "$home_assistant_state_max$"
-      description = "Max for performance data"
-    }
-    "--attribute" = {
-      value = "$home_assistant_state_attribute$"
-      description = "Check attribute instead of value"
-    }
-    "--filter" = {
-      value = "$home_assistant_state_filter$"
-      description = "Filter by 'attribute=value' (can be an array)"
-    }
-    "--friendly" = {
-      set_if = "$home_assistant_state_friendly$"
-      description = "Use friendly name, when available"
-    }
-  }
-}
diff --git a/check_home_assistant_state.py b/check_home_assistant_state.py
index 51aa492..1a11a02 100755
--- a/check_home_assistant_state.py
+++ b/check_home_assistant_state.py
@@ -6,6 +6,7 @@ import logging
 import sys
 from urllib.parse import urljoin
 from typing import Optional
+from pathlib import Path
 
 import requests
 import nagiosplugin
@@ -83,6 +84,56 @@ def key_value(arg: str):
     return k, v
 
 
+class Icinga2ConfAction(argparse.Action):
+    def __init__(
+        self,
+        option_strings,
+        dest=argparse.SUPPRESS,
+        default=argparse.SUPPRESS,
+        help="Generate conf file for icinga2 CheckCommand",
+    ):
+        super().__init__(
+            option_strings=option_strings,
+            dest=dest,
+            default=default,
+            nargs=0,
+            help=help,
+        )
+
+    def __call__(
+        self, parser: argparse.ArgumentParser, namespace, values, option_string=None
+    ):
+        filename = Path(__file__).absolute()
+        command_name = filename.stem.removeprefix("check_")
+        # FIXME: assumes that script will be in a subdirectory of PluginContribDir
+        command_path = filename.relative_to(filename.parents[1])
+
+        print(f'object CheckCommand "{command_name}" {{')
+        print(f'  command = [ PluginContribDir + "/{command_path}" ]')
+        print("  arguments = {")
+        for action in parser._actions:
+            if action.dest in ["verbose", "help", self.dest]:
+                continue
+
+            arg_str = action.option_strings[-1]
+            icinga2_var = arg_str.lstrip("-").replace("-", "_")
+            print(f'    "{arg_str}" = {{')
+
+            if action.required:
+                print("      required = true")
+
+            if isinstance(action, argparse._StoreConstAction):
+                print(f'      set_if = "${command_name}_{icinga2_var}$"')
+            else:
+                print(f'      value = "${command_name}_{icinga2_var}$"')
+
+            print(f'      description = "{action.help}"')
+            print("    }")
+
+        print("  }\n}")
+        parser.exit()
+
+
 @nagiosplugin.guarded
 def main():
     argp = argparse.ArgumentParser(description=__doc__)
@@ -93,6 +144,7 @@ def main():
         "-u", "--url", required=True, type=str, help="URL for Home Assistant"
     )
     argp.add_argument("-v", "--verbose", action="count", default=0)
+    argp.add_argument("--make-icinga-conf", action=Icinga2ConfAction)
 
     argp.add_argument(
         "-d",