Update "service apply for" documentation using a more real-world example

fixes #9270
This commit is contained in:
Michael Friedrich 2015-05-13 14:14:30 +02:00
parent b5740a6171
commit b9f05aefe8
1 changed files with 149 additions and 39 deletions

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@ -575,7 +575,7 @@ The service's `display_name` should be set to the identifier inside the dictiona
ignore where identifier == "bgp" //don't generate service for bgp checks
}
Icinga 2 evalatues the `apply for` rule for all objects with the custom attribute
Icinga 2 evaluates the `apply for` rule for all objects with the custom attribute
`oids` set. It then iterates over all list items inside the `for` loop and evaluates the
`assign/ignore where` expressions. You can access the loop variable
in these expressions, e.g. for ignoring certain values.
@ -594,38 +594,52 @@ generic `apply for` rule generating the object name with or without a prefix.
#### <a id="using-apply-for-custom-attribute-override"></a> Apply For and Custom Attribute Override
Imagine a different more advanced example: You are monitoring your switch (hosts) with many
interfaces (services). The following requirements/problems apply:
Imagine a different more advanced example: You are monitoring your network device (host)
with many interfaces (services). The following requirements/problems apply:
* Each interface service check should be named with a prefix and a running number
* Each interface service check should be named with a prefix and a name defined in your host object (which could be generated from your CMDB, etc)
* Each interface has its own vlan tag
* Some interfaces have QoS enabled
* Additional attributes such as `display_name` or `notes, `notes_url` and `action_url` must be
dynamically generated
By defining the `interfaces` dictionary with three example interfaces on the `core-switch`
host object, you'll make sure to pass the storage required by the for loop in the service apply
rule.
object Host "core-switch" {
Tip: Define the snmp community as global constant in your [constants.conf](5-configuring-icinga-2.md#constants-conf) file.
const IftrafficSnmpCommunity = "public"
By defining the `interfaces` dictionary with three example interfaces on the `cisco-catalyst-6509-34`
host object, you'll make sure to pass the [custom attribute](3-monitoring-basics.md#custom-attributes)
storage required by the for loop in the service apply rule.
object Host "cisco-catalyst-6509-34" {
import "generic-host"
address = "127.0.0.1"
display_name = "Catalyst 6509 #34 VIE21"
address = "127.0.1.4"
vars.interfaces["0"] = {
port = 1
vlan = "internal"
address = "127.0.0.2"
qos = "enabled"
/* "GigabitEthernet0/2" is the interface name,
* and key name in service apply for later on
*/
vars.interfaces["GigabitEthernet0/2"] = {
/* define all custom attributes with the
* same name required for command parameters/arguments
* in service apply (look into your CheckCommand definition)
*/
iftraffic_units = "g"
iftraffic_community = IftrafficSnmpCommunity
vlan = "internal"
qos = "disabled"
}
vars.interfaces["1"] = {
port = 2
vlan = "mgmt"
address = "127.0.1.2"
vars.interfaces["GigabitEthernet0/4"] = {
iftraffic_units = "g"
//iftraffic_community = IftrafficSnmpCommunity
vlan = "renote"
qos = "enabled"
}
vars.interfaces["2"] = {
port = 3
vlan = "remote"
address = "127.0.2.2"
vars.interfaces["MgmtInterface1"] = {
iftraffic_community = IftrafficSnmpCommunity
vlan = "mgmt"
interface_address = "127.99.0.100" #special management ip
}
}
@ -633,32 +647,77 @@ You can also omit the `"if-"` string, then all generated service names are direc
taken from the `if_name` variable value.
The config dictionary contains all key-value pairs for the specific interface in one
loop cycle, like `port`, `vlan`, `address` and `qos` for the `0` interface.
loop cycle, like `iftraffic_units`, `vlan`, and `qos` for the specified interface.
By defining a default value for the custom attribute `qos` in the `vars` dictionary
before adding the `config` dictionary we'll ensure that this attribute is always defined.
You can either map the custom attributes from the `interface_config` dictionary to
local custom attributes stashed into `vars`. If the names match the required command
argument parameters already (for example `iftraffic_units`), you could also add the
`interface_config` dictionary to the `vars` dictionary using the `+=` operator.
After `vars` is fully populated, all object attributes can be set. For strings, you can use
string concatention with the `+` operator.
After `vars` is fully populated, all object attributes can be set calculated from
provided host attributes. For strings, you can use string concatention with the `+` operator.
You can also specifiy the check command that way.
You can also specifiy the display_name, check command, interval, notes, notes_url, action_url, etc.
attributes that way.
apply Service "if-" for (if_name => config in host.vars.interfaces) {
This example also uses [if conditions](19-language-reference.md#conditional-statements)
if specific values are not set, adding a local default value.
The other way around you can override specific custom attributes inherited from a service template,
if set.
/* loop over the host.vars.interfaces dictionary
* for (key => value in dict) means `interface_name` as key
* and `interface_config` as value. Access config attributes
* with the indexer (`.`) character.
*/
apply Service "if-" for (interface_name => interface_config in host.vars.interfaces) {
import "generic-service"
check_command = "ping4"
check_command = "iftraffic"
display_name = "IF-" + interface_name
vars.qos = "disabled"
vars += config
/* use the key as command argument (no duplication of values in host.vars.interfaces) */
vars.iftraffic_interface = interface_name
display_name = "if-" + if_name + "-" + vars.vlan
/* set the global constant if not explicitely set a) not set in the imported service template
* b) not provided by the `interfaces` dictionary on the host
*/
if (interface_config.iftraffic_community == "" || vars.iftraffic_community == "") {
vars.iftraffic_community = IftrafficSnmpCommunity
}
notes = "Interface check for Port " + string(vars.port) + " in VLAN " + vars.vlan + " on Address " + vars.address + " QoS " + vars.qos
/* map the custom attributes as command arguments */
vars.iftraffic_units = interface_config.iftraffic_units
vars.iftraffic_community = interface_config.iftraffic_community
/* the above can be achieved in a shorter fashion if the names inside host.vars.interfaces
* are the _exact_ same as required as command parameter by the check command
* definition.
*/
vars += interface_config
/* set a default value for units */
if (interface_config.iftraffic_units == "") {
vars.iftraffic_units = "b"
}
if (interface_config.vlan == "") {
vars.vlan = "not set"
}
if (interface_config.qos == "") {
vars.qos = "not set"
}
/* Calculate some additional object attributes after populating the `vars` dictionary */
notes = "Interface check for " + interface_name + " (units: '" + interface_config.iftraffic_units + "') in VLAN '" + vars.vlan + "' on address '" + vars.interface_address + "' QoS '" + vars.qos + "'"
notes_url = "http://foreman.company.com/hosts/" + host.name
action_url = "http://snmp.checker.company.com/" + host.name + "if-" + if_name
action_url = "http://snmp.checker.company.com/" + host.name + "/if-" + interface_name
}
Note that numbers must be explicitely casted to string when adding to strings.
This can be achieved by wrapping them into the [string()](19-language-reference.md#function-calls) function.
This example makes use of the [check_iftraffic](https://exchange.icinga.org/exchange/iftraffic) plugin.
The `CheckCommand` definition can be found in the
[contributed plugin check commands](7-icinga-template-library.md#plugins-contrib-command-iftraffic)
- make sure to include them in your [icinga2 configuration file](5-configuring-icinga-2.md#icinga2-conf).
> **Tip**
>
@ -666,6 +725,57 @@ This can be achieved by wrapping them into the [string()](19-language-reference.
> of the generated objects. Use the `object list` [CLI command](8-cli-commands.md#cli-command-object)
> after successful [configuration validation](8-cli-commands.md#config-validation).
Verify that the apply-for-rule succesfully created the service objects with the
inherited custom attributes:
# icinga2 daemon -C
# icinga2 object list --type Service --name *catalyst*
Object 'cisco-catalyst-6509-34!if-GigabitEthernet0/2' of type 'Service':
...
* vars
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 62:3-62:26
* iftraffic_community = "public"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 51:5-51:53
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 56:3-56:65
* iftraffic_interface = "GigabitEthernet0/2"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 45:3-45:43
* iftraffic_units = "g"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 55:3-55:57
* qos = "disabled"
* vlan = "internal"
Object 'cisco-catalyst-6509-34!if-GigabitEthernet0/4' of type 'Service':
...
* vars
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 62:3-62:26
* iftraffic_community = null
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 51:5-51:53
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 56:3-56:65
* iftraffic_interface = "GigabitEthernet0/4"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 45:3-45:43
* iftraffic_units = "g"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 55:3-55:57
* qos = "enabled"
* vlan = "renote"
Object 'cisco-catalyst-6509-34!if-MgmtInterface1' of type 'Service':
...
* vars
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 62:3-62:26
* iftraffic_community = "public"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 51:5-51:53
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 56:3-56:65
* iftraffic_interface = "MgmtInterface1"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 45:3-45:43
* iftraffic_units = "b"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 55:3-55:57
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 66:5-66:30
* interface_address = "127.99.0.100"
* qos = "not set"
% = modified in '/etc/icinga2/conf.d/iftraffic.conf', lines 72:5-72:24
* vlan = "mgmt"
### <a id="using-apply-object-attributes"></a> Use Object Attributes in Apply Rules