generate-icinga-generic-host: Use Jinja2 for config templating

Generating the config with a bunch of string generation is tedious and
not so well to read. Thus, using Jinja2 to create a template and then
just passing the variables is a sensible choice. This commit removes all
string-generating functions and replaces it with Jinja2 templating.
Signed-off-by: Adrian 'nex' Schollmeyer <adrian.schollmeyer@fem.tu-ilmenau.de>

generate-icinga-generic-host.py

@@ -5,6 +5,7 @@ import re
 import json
 from argparse import ArgumentParser
 from fem_netbox import cli_common
+import jinja2
 
 LINUX_PLATFORMS=[
         "linux",
@@ -12,6 +13,10 @@ LINUX_PLATFORMS=[
         "gentoo"
         ]
 
+j2_env = jinja2.Environment(
+        loader=jinja2.PackageLoader("netbox_icinga_generator", "templates")
+)
+
 class Icinga2Host:
     def __init__(
             self,
@@ -104,115 +109,9 @@ class Icinga2Host:
 
 
     def create_icinga2_config(self):
-        text = "object Host \"" + f"{self.name}" + "\" {\n"
-        text += "\timport \"netbox-generated-host\"\n\n"
-
-        text += self.create_icinga2_address_fields()
-        text += self.create_icinga2_attribute_fields()
-        text += self.create_icinga2_ping_fields()
-        text += self.create_icinga2_ssh_port_field()
-        text += self.create_icinga2_check_fields()
-
-        text += "\timport \"netbox-generated-host-extras\"\n"
-        text += "}"
-        return text
-
-
-    def create_icinga2_attribute_fields(self):
-        text = ""
-        if self.parent:
-            text += "\tvars.parent = \"" + f"{self.parent}" + "\"\n"
-        if self.host_class:
-            text += "\tvars.host_class = \"" + f"{self.host_class}" + "\"\n"
-        if self.os:
-            text += "\tvars.os = \"" + f"{self.os}" + "\"\n"
-
-        if not text == "":
-            text += "\n"
-        return text
-
-
-    def create_icinga2_address_fields(self):
-        text = ""
-        if self.address:
-            text += "\taddress = \"" + f"{self.address}" + "\"\n"
-        if self.address6:
-            text += "\taddress6 = \"" + f"{self.address6}" + "\"\n"
-        text += self.create_paragraph(text)
-
-        return text
-
-
-    def create_icinga2_ping_fields(self):
-        text = ""
-        for ip in self.ips:
-            text += "\tvars.ping[\"" + f"{ip}" + "\"] = {}\n"
-        for ip6 in self.ip6s:
-            text += "\tvars.ping6[\"" + f"{ip6}" + "\"] = {}\n"
-        text += self.create_paragraph(text)
-
-        return text
-
-
-    def create_icinga2_ssh_port_field(self):
-        text = ""
-        if self.ssh_port:
-            text += "\tvars.ssh_port = \"" + f"{self.ssh_port}" + "\"\n\n"
-        extra_ssh_port_num = 0
-        for ssh_port in self.additional_ssh_ports:
-            text += "\tvars.ssh[\"" + \
-                    f"{extra_ssh_port_num}" + \
-                    "\"] = {ssh_port = \"" + \
-                    f"{ssh_port}" \
-                    +"\"}\n"
-            extra_ssh_port_num += 1
-        if extra_ssh_port_num > 0:
-            text += self.create_paragraph(text)
-        return text
-
-
-    def create_icinga2_check_fields(self):
-        text = ""
-
-        if self.apt:
-            text = "\tvars.apt_" + f"{self.apt}" + " = {}\n\n"
-
-        procs_text = ""
-        for procs_check in self.procs:
-            text += "\tvars.procs[\"" + f"{procs_check.name}" + "\"] = {}\n"
-        text += procs_text + self.create_paragraph(procs_text)
-
-        disk_text = ""
-        for disk in self.smart:
-            disk_text += "\tvars.smart[\"" + f"{disk}" + "\"] = {}\n"
-        text += disk_text + self.create_paragraph(disk_text)
-
-        disk_text = ""
-        for disk in self.smart_sectors:
-            disk_text += "\tvars.smart_sectors[\"" + f"{disk}" + "\"] = {}\n"
-        text += disk_text + self.create_paragraph(disk_text)
-
-        nrpe_text = ""
-        if self.nrpe:
-            nrpe_text += "\tvars.nrpe = true\n"
-            for nrpe_check in self.nrpe_checks:
-                nrpe_text += \
-                        "\tvars.nrpe_check[\"" + f"{nrpe_check}" + "\"] = {}\n"
-            nrpe_text += "\n"
-            for nrpe_disk in self.nrpe_disks:
-                nrpe_text += "\tvars.nrpe_disk[\"" + \
-                        f"check_{nrpe_disk}_disk" + "\"] = {}\n"
-            nrpe_text += "\n"
-        text += nrpe_text
-
-        return text
-
-
-    def create_paragraph(self, text):
-        if text == "":
-            return ""
-        else:
-            return "\n"
+        global j2_env
+        template = j2_env.get_template("generic-host.j2")
+        return template.render(vars=self)
 
 
 class Icinga2ProcsCheck:
@@ -357,12 +256,46 @@ def create_icinga2_host_object_from_netbox(netbox, device_name):
     try:
         monitoring_config_context = device.config_context["monitoring"]
 
-        if monitoring_config_context["nrpe_enabled"]:
-            host.enable_nrpe()
-            for nrpe_check in monitoring_config_context["nrpe_checks"]:
-                host.add_nrpe_check(nrpe_check)
-            for nrpe_disk in monitoring_config_context["nrpe_disks"]:
-                host.add_nrpe_disk(nrpe_disk)
+        try:
+            apt = monitoring_config_context["apt"]
+            if apt == "active":
+                host.add_apt_active()
+            elif apt == "passive":
+                host.add_apt_passive()
+            else:
+                raise Exception(
+                        f"Invalid apt configuration '{apt}'! "
+                        "Must be either active or passive")
+        except KeyError:
+            pass
+
+        try:
+            for smart in monitoring_config_context["smart"]:
+                host.add_smart(smart)
+        except KeyError:
+            pass
+
+        try:
+            for smart_sector in monitoring_config_context["smart_sectors"]:
+                host.add_smart_sectors(smart_sector)
+        except KeyError:
+            pass
+
+        try:
+            if monitoring_config_context["nrpe_enabled"]:
+                host.enable_nrpe()
+                try:
+                    for nrpe_check in monitoring_config_context["nrpe_checks"]:
+                        host.add_nrpe_check(nrpe_check)
+                except KeyError:
+                    pass
+                try:
+                    for nrpe_disk in monitoring_config_context["nrpe_disks"]:
+                        host.add_nrpe_disk(nrpe_disk)
+                except KeyError:
+                    pass
+        except KeyError:
+            pass
     except KeyError as e:
         pass # So there is no extra monitoring config. Who cares anyway?
 

netbox_icinga_generator/templates/generic-host.j2

+object Host "{{ vars.name }}" {
+	import "netbox-generated-host"
+
+	// === ADDRESSING ===
+	{% if vars.address is defined %}address = "{{ vars.address }}"{% endif %}
+	{% if vars.address6 is defined %}address6 = "{{ vars.address6 }}"{% endif %}
+
+	// === SYSTEM ATTRIBUTES ===
+	{%- if vars.parent is defined %}
+	vars.parent = "{{ vars.parent }}"{% endif %}
+	{%- if vars.host_class is defined %}
+	vars.host_class = "{{ vars.host_class }}"{% endif %}
+	{%- if vars.os is defined %}
+	vars.os = "{{ vars.os }}"{% endif %}
+
+	// === CONNECTIVITY CHECKS ===
+	{%- for ip in vars.ips %}
+	vars.ping["{{ ip }}"] = {}{% endfor %}
+	{%- for ip6 in vars.ip6s %}
+	vars.ping6["{{ ip6 }}"] = {}{% endfor %}
+
+	{% if vars.ssh_port %}vars.ssh_port = "{{ vars.ssh_port }}"{% endif %}
+
+	// === SYSTEM HEALTH CHECKS ===
+	{%- if vars.apt %}vars.apt_{{ vars.apt }} = {}{% endif %}
+
+	{% for check in vars.procs %}
+	vars.procs["{{ check }}"] = {}{% endfor %}
+
+	{% for disk in vars.smart %}
+	vars.smart["{{ disk }}"] = {}{% endfor %}
+	{%- for disk in vars.smart_sectors %}
+	vars.smart_sectors["{{ disk }}"] = {}{% endfor %}
+
+	{% if vars.nrpe is defined %}vars.nrpe = true{% endif %}
+	{% for check in vars.nrpe_checks %}
+	vars.nrpe_check["check_{{ check }}"] = {}{% endfor %}
+	{% for check in vars.nrpe_disks %}
+	vars.nrpe_disk["check_{{ check }}_disk"] = {}{% endfor %}
+
+	import "netbox-generated-host-extras"
+}