9.1 KiB
Configuration Syntax
Object Definition
Icinga 2 features an object-based configuration format. In order to define objects the object keyword is used:
object Host "host1.example.org" {
display_name = "host1",
check_interval = 30,
retry_interval = 15,
macros = {
address = "192.168.0.1"
}
}
Note
The Icinga 2 configuration format is agnostic to whitespaces and new-lines.
Note
Colons (:) are not permitted in object names.
Each object is uniquely identified by its type (Host) and name (host1.example.org). Objects can contain a comma-separated list of property declarations. The following data types are available for property values:
Numeric Literals
A floating-point number.
Example:
-27.3
Duration Literal
Similar to floating-point numbers except for that fact that they support suffixes to help with specifying time durations.
Example:
2.5m
Supported suffixes include ms (milliseconds), s (seconds), m (minutes) and h (hours).
String Literals
A string.
Example:
"Hello World!"
Certain characters need to be escaped. The following escape sequences are supported:
Character Escape sequence " \" <TAB> \t <CARRIAGE-RETURN> \r <LINE-FEED> \n <BEL> \b <FORM-FEED> \f
In addition to these pre-defined escape sequences you can specify arbitrary ASCII characters using the backslash character (\) followed by an ASCII character in octal encoding.
Multiline String Literals
Strings spanning multiple lines can be specified by enclosing them in {{{ and }}}.
Example.
{{{This
is
a multi-line
string.}}}
Boolean Literals
The keywords true and false are equivalent to 1 and 0 respectively.
Null Value
The null keyword can be used to specify an empty value.
Dictionary
An unordered list of key-value pairs. Keys must be unique and are compared in a case-insensitive manner.
Individual key-value pairs must be separated from each other with a comma. The comma after the last key-value pair is optional.
Example:
{
address = "192.168.0.1",
port = 443
}
Note
Identifiers may not contain certain characters (e.g. space) or start with certain characters (e.g. digits). If you want to use a dictionary key that is not a valid identifier you can put the key in double quotes.
Note
Setting a dictionary key to null causes the key to be removed from the dictionary.
Array
An ordered list of values.
Individual array elements must be separated from each other with a comma. The comma after the last element is optional.
Example:
[
"hello",
"world",
42,
[ "a", "nested", "array" ]
]
Note
An array may simultaneously contain values of different types, e.g. strings and numbers.
Operators
In addition to the = operator shown above a number of other operators to manipulate configuration objects are supported. Here’s a list of all available operators:
Operator =
Sets a dictionary element to the specified value.
Example:
{
a = 5,
a = 7
}
In this example a has the value 7 after both instructions are executed.
Operator +=
Modifies a dictionary or array by adding new elements to it.
Example:
{
a = [ "hello" ],
a += [ "world" ]
}
In this example a contains both "hello" and "world". This currently only works for dictionaries and arrays. Support for numbers might be added later on.
Operator -=
Removes elements from a dictionary.
Example:
{
a = { "hello", "world" },
a -= { "world" }
}
In this example a contains "hello". Trying to remove an item that does not exist is not an error. Not implemented yet.
Operator *=
Multiplies an existing dictionary element with the specified number. If the dictionary element does not already exist 0 is used as its value.
Example:
{
a = 60,
a *= 5
}
In this example a is 300. This only works for numbers. Not implemented yet.
Operator /=
Divides an existing dictionary element by the specified number. If the dictionary element does not already exist 0 is used as its value.
Example:
{
a = 300,
a /= 5
}
In this example a is 60. This only works for numbers. Not implemented yet.
Attribute Shortcuts
Indexer Shortcut
Example:
{
hello["key"] = "world"
}
This is equivalent to writing:
{
hello += {
key = "world"
}
}
Specifiers
Objects can have specifiers that have special meaning. The following specifiers can be used (prefacing the object keyword):
Specifier abstract
This specifier identifies the object as a template which can be used by other object definitions. The object will not be instantiated on its own.
Instead of using the abstract specifier you can use the template keyword which is a shorthand for writing abstract object:
template Service "http" {
...
}
Specifier local
This specifier disables replication for this object. The object will not be sent to remote Icinga instances.
Inheritance
Objects can inherit attributes from one or more other objects.
Example:
template Host "default-host" {
check_interval = 30,
macros = {
color = "red"
}
}
template Host "test-host" inherits "default-host" {
macros += {
color = "blue"
}
}
object Host "localhost" inherits "test-host" {
macros += {
address = "127.0.0.1",
address6 = "::1"
}
}
Note
The "default-host" and "test-host" objects are marked as templates using the abstract keyword. Parent objects do not necessarily have to be abstract though in general they are.
Note
The += operator is used to insert additional properties into the macros dictionary. The final dictionary contains all 3 macros and the property color has the value "blue".
Parent objects are resolved in the order they’re specified using the inherits keyword.
Comments
The Icinga 2 configuration format supports C/C++-style comments.
Example:
/*
This is a comment.
*/
object Host "localhost" {
check_interval = 30, // this is also a comment.
retry_interval = 15
}
Includes
Other configuration files can be included using the include directive. Paths must be relative to the configuration file that contains the include directive.
Example:
include "some/other/file.conf"
include "conf.d/*.conf"
Note
Wildcard includes are not recursive.
Icinga also supports include search paths similar to how they work in a C/C++ compiler:
include <itl/itl.conf>
Note the use of angle brackets instead of double quotes. This causes the config compiler to search the include search paths for the specified file. By default $PREFIX/icinga2 is included in the list of search paths.
Wildcards are not permitted when using angle brackets.
Library directive
The library directive can be used to manually load additional libraries. Upon loading these libraries may provide additional types or methods.
Example:
library "snmphelper"
Note
The icinga library is automatically loaded at startup.
Type Definition
By default Icinga has no way of semantically verifying its configuration objects. This is where type definitions come in. Using type definitions you can specify which attributes are allowed in an object definition.
Example:
type Pizza {
%require "radius",
%attribute number "radius",
%attribute dictionary "ingredients" {
%validator "ValidateIngredients",
%attribute string "*",
%attribute dictionary "*" {
%attribute number "quantity",
%attribute string "name"
}
},
%attribute any "custom::*"
}
The Pizza definition provides the following validation rules:
-
Pizza objects must contain an attribute radius which has to be a number.
-
Pizza objects may contain an attribute ingredients which has to be a dictionary.
-
Elements in the ingredients dictionary can be either a string or a dictionary.
-
If they’re a dictionary they may contain attributes quantity (of type number) and name (of type string).
-
The script function ValidateIngredients is run to perform further validation of the ingredients dictionary.
-
Pizza objects may contain attribute matching the pattern custom::* of any type.
Valid types for type rules include: * any * number * string * scalar (an alias for string) * dictionary