Documentation: Revamp getting started and fix smaller bugs

fixes #6869
fixes #6995
fixes #6867
fixes #6864
fixes #6839
fixes #6651
refs #6968

doc/2-getting-started.md

@@ -14,8 +14,8 @@ and distribution you are running.
 
   Distribution            | Repository
   ------------------------|---------------------------
-  Debian                  | [Icinga Repository](http://packages.icinga.org/debian/), [Upstream](https://packages.debian.org/sid/icinga2), [DebMon](http://debmon.org/packages/debmon-wheezy/icinga2)
+  Debian                  | [Upstream](https://packages.debian.org/sid/icinga2), [DebMon](http://debmon.org/packages/debmon-wheezy/icinga2), [Icinga Repository](http://packages.icinga.org/debian/)
-  Ubuntu                  | [Icinga Repository](http://packages.icinga.org/ubuntu/), [Upstream](https://launchpad.net/ubuntu/+source/icinga2)
+  Ubuntu                  | [Upstream](https://launchpad.net/ubuntu/+source/icinga2), [Icinga PPA](https://launchpad.net/~formorer/+archive/ubuntu/icinga), [Icinga Repository](http://packages.icinga.org/ubuntu/)
   RHEL/CentOS             | [Icinga Repository](http://packages.icinga.org/epel/)
   OpenSUSE                | [Icinga Repository](http://packages.icinga.org/openSUSE/), [Server Monitoring Repository](https://build.opensuse.org/package/show/server:monitoring/icinga2)
   SLES                    | [Icinga Repository](http://packages.icinga.org/SUSE/)
@@ -26,17 +26,69 @@ and distribution you are running.
 Packages for distributions other than the ones listed above may also be
 available. Please contact your distribution packagers.
 
-The packages for RHEL/CentOS 5 depend on other packages which are distributed
+### <a id="installing-requirements"></a> Installing Requirements for Icinga 2
+
+You need to add the Icinga repository to your package management configuration.
+Below is a list with examples for the various distributions.
+
+Debian (debmon):
+    # wget -O - http://debmon.org/debmon/repo.key 2>/dev/null | apt-key add -
+    # cat >/etc/apt/sources.list.d/debmon.list<<EOF
+    deb http://debmon.org/debmon debmon-wheezy main
+    EOF
+    # apt-get update
+
+Ubuntu (PPA):
+    # add-apt-repository ppa:formorer/icinga
+    # apt-get update
+
+RHEL/CentOS:
+    # rpm --import http://packages.icinga.org/icinga.key
+    # wget http://packages.icinga.org/epel/ICINGA-release.repo -O /etc/yum.repos.d/ICINGA-release.repo
+    # yum makecache
+
+Fedora:
+    # wget http://packages.icinga.org/fedora/ICINGA-release.repo -O /etc/yum.repos.d/ICINGA-release.repo
+    # yum makecache
+
+SLES:
+    # zypper ar http://packages.icinga.org/SUSE/ICINGA-release.repo
+    # zypper ref
+
+OpenSUSE:
+    # zypper ar http://packages.icinga.org/openSUSE/ICINGA-release.repo
+    # zypper ref
+
+The packages for RHEL/CentOS depend on other packages which are distributed
 as part of the [EPEL repository](http://fedoraproject.org/wiki/EPEL). Please
-make sure to enable this repository.
+make sure to enable this repository by following
+[these instructions](#http://fedoraproject.org/wiki/EPEL#How_can_I_use_these_extra_packages.3F).
+
+### <a id="installing-icinga2"></a> Installing Icinga 2
 
 You can install Icinga 2 by using your distribution's package manager
 to install the `icinga2` package.
 
+Debian/Ubuntu:
+    # apt-get install icinga2
+
+RHEL/CentOS/Fedora:
+    # yum install icinga2
+
+SLES/OpenSUSE:
+    # zypper install icinga2
+
 On RHEL/CentOS and SLES you will need to use `chkconfig` to enable the
-`icinga2` service. You can manually start Icinga 2 using `/etc/init.d/icinga2 start`.
+`icinga2` service. You can manually start Icinga 2 using `service icinga2 start`.
+
+    # chkconfig icinga2 on
+    # service icinga2 start
+
 RHEL/CentOS 7 use [Systemd](#systemd-service) with `systemctl {enable,start} icinga2`.
 
+    # systemctl enable icinga2
+    # systemctl start icinga2
+
 Some parts of Icinga 2's functionality are available as separate packages:
 
   Name                    | Description
@@ -88,6 +140,92 @@ By default Icinga 2 uses the following files and directories:
   /var/lib/icinga2                    | Icinga 2 state file, cluster feature replay log and configuration files.
   /var/log/icinga2                    | Log file location and compat/ directory for the CompatLogger feature.
 
+## <a id="setting-up-check-plugins"></a> Setting up Check Plugins
+
+Without plugins Icinga 2 does not know how to check external services. The
+[Monitoring Plugins Project](https://www.monitoring-plugins.org/) provides
+an extensive set of plugins which can be used with Icinga 2 to check whether
+services are working properly.
+
+The recommended way of installing these standard plugins is to use your
+distribution's package manager.
+
+> **Note**
+>
+> The `Nagios Plugins` project was renamed to `Monitoring Plugins`
+> in January 2014. At the time of this writing some packages are still
+> using the old name while some distributions have adopted the new package
+> name `monitoring-plugins` already.
+
+> **Note**
+>
+> EPEL for RHEL/CentOS 7 is still in beta mode at the time of writing and does
+> not provide a `monitoring-plugins` package. You are required to manually install
+> them.
+
+For your convenience here is a list of package names for some of the more
+popular operating systems/distributions:
+
+OS/Distribution        | Package Name       | Installation Path
+-----------------------|--------------------|---------------------------
+RHEL/CentOS (EPEL)     | nagios-plugins-all | /usr/lib/nagios/plugins or /usr/lib64/nagios/plugins
+Debian                 | nagios-plugins     | /usr/lib/nagios/plugins
+FreeBSD                | nagios-plugins     | /usr/local/libexec/nagios
+OS X (MacPorts)        | nagios-plugins     | /opt/local/libexec
+
+Depending on which directory your plugins are installed into you may need to
+update the global `PluginDir` constant in your Icinga 2 configuration. This macro is used
+by the service templates contained in the Icinga Template Library to determine
+where to find the plugin binaries.
+
+### <a id="integrate-additional-plugins"></a> Integrate Additional Plugins
+
+For some services you may need additional 'check plugins' which are not provided
+by the official Monitoring Plugins project.
+
+All existing Nagios or Icinga 1.x plugins work with Icinga 2. Here's a
+list of popular community sites which host check plugins:
+
+* [MonitoringExchange](https://www.monitoringexchange.org)
+* [Icinga Wiki](https://wiki.icinga.org)
+
+The recommended way of setting up these plugins is to copy them to a common directory
+and create an extra global constant, e.g. `CustomPluginDir` in your [constants.conf](#constants-conf)
+configuration file:
+
+    # cp check_snmp_int.pl /opt/plugins
+    # chmod +x /opt/plugins/check_snmp_int.pl
+
+    # cat /etc/icinga2/constants.conf
+    /**
+     * This file defines global constants which can be used in
+     * the other configuration files. At a minimum the
+     * PluginDir constant should be defined.
+     */
+
+    const PluginDir = "/usr/lib/nagios/plugins"
+    const CustomPluginDir = "/opt/monitoring"
+
+Prior to using the check plugin with Icinga 2 you should ensure that it is working properly
+by trying to run it on the console using whichever user Icinga 2 is running as:
+
+    # su - icinga -s /bin/bash
+    $ /opt/plugins/check_snmp_int.pl --help
+
+Additional libraries may be required for some plugins. Please consult the plugin
+documentation and/or plugin provided README for installation instructions.
+
+Each plugin requires a [CheckCommand](#objecttype-checkcommand) object in your
+configuration which can be used in the [Service](#objecttype-service) or
+[Host](#objecttype-host) object definition. Examples for `CheckCommand`
+objects can be found in the [Plugin Check Commands](#plugin-check-commands) shipped
+with Icinga 2.
+For further information on your monitoring configuration read the
+[monitoring basics](#monitoring-basics).
+
+
+## <a id="configuring-icinga2-first-steps"></a> Configuring Icinga 2: First Steps
+
 ### <a id="icinga2-conf"></a> icinga2.conf
 
 An example configuration file is installed for you in `/etc/icinga2/icinga2.conf`.
@@ -365,84 +503,6 @@ their check commands.
 Further details on the monitoring configuration can be found in the
 [monitoring basics](#monitoring-basics) chapter.
 
-## <a id="setting-up-check-plugins"></a> Setting up Check Plugins
-
-Without plugins
-Icinga 2 does not know how to check external services. The
-[Monitoring Plugins Project](https://www.monitoring-plugins.org/) provides
-an extensive set of plugins which can be used with Icinga 2 to check whether
-services are working properly.
-
-The recommended way of installing these standard plugins is to use your
-distribution's package manager.
-
-> **Note**
->
-> The `Nagios Plugins` project was renamed to `Monitoring Plugins`
-> in January 2014. At the time of this writing the packages are still
-> using the old name.
-
-For your convenience here is a list of package names for some of the more
-popular operating systems/distributions:
-
-OS/Distribution        | Package Name       | Installation Path
------------------------|--------------------|---------------------------
-RHEL/CentOS (EPEL)     | nagios-plugins-all | /usr/lib/nagios/plugins or /usr/lib64/nagios/plugins
-Debian                 | nagios-plugins     | /usr/lib/nagios/plugins
-FreeBSD                | nagios-plugins     | /usr/local/libexec/nagios
-OS X (MacPorts)        | nagios-plugins     | /opt/local/libexec
-
-Depending on which directory your plugins are installed into you may need to
-update the global `PluginDir` constant in your Icinga 2 configuration. This macro is used
-by the service templates contained in the Icinga Template Library to determine
-where to find the plugin binaries.
-
-### <a id="integrate-additional-plugins"></a> Integrate Additional Plugins
-
-For some services you may need additional 'check plugins' which are not provided
-by the official Monitoring Plugins project.
-
-All existing Nagios or Icinga 1.x plugins should work with Icinga 2. Here's a
-list of popular community sites which host check plugins:
-
-* [MonitoringExchange](https://www.monitoringexchange.org)
-* [Icinga Wiki](https://wiki.icinga.org)
-
-The recommended way of setting up these plugins is to copy them to a common directory
-and create an extra global constant, e.g. `CustomPluginDir` in your `constants.conf`
-configuration file:
-
-    # cp check_snmp_int.pl /opt/plugins
-    # chmod +x /opt/plugins/check_snmp_int.pl
-
-    # cat /etc/icinga2/constants.conf
-    /**
-     * This file defines global constants which can be used in
-     * the other configuration files. At a minimum the
-     * PluginDir constant should be defined.
-     */
-
-    const PluginDir = "/usr/lib/nagios/plugins"
-    const CustomPluginDir = "/opt/monitoring"
-
-Prior to using the check plugin with Icinga 2 you should ensure that it is working properly
-by trying to run it on the console using whichever user Icinga 2 is running as:
-
-    # su - icinga -s /bin/bash
-    $ /opt/plugins/check_snmp_int.pl --help
-
-Additional libraries may be required for some plugins. Please consult the plugin
-documentation and/or plugin provided README for installation instructions.
-
-Each plugin requires a [CheckCommand](#objecttype-checkcommand) object in your
-configuration which can be used in the [Service](#objecttype-service) or
-[Host](#objecttype-host) object definition. Examples for `CheckCommand`
-objects can be found in the [Plugin Check Commands](#plugin-check-commands) shipped
-with Icinga 2.
-For further information on your monitoring configuration read the
-[monitoring basics](#monitoring-basics).
-
-
 ## <a id="configuring-db-ido"></a> Configuring DB IDO
 
 The DB IDO (Database Icinga Data Output) modules for Icinga 2 take care of exporting
@@ -455,8 +515,9 @@ both MySQL and PostgreSQL is implemented.
 Icinga 2 uses the Icinga 1.x IDOUtils database schema. Icinga 2 requires additional
 features not yet released with older Icinga 1.x versions.
 
-* Current required schema version: `1.11.6`.
+> **Note**
-
+>
+> Please check the [what's new](#whats-new) section for the required schema version.
 
 > **Tip**
 >
@@ -464,8 +525,69 @@ features not yet released with older Icinga 1.x versions.
 > you to do so (for example, [Icinga Web](#setting-up-icinga-web) or [Icinga Web 2](#setting-up-icingaweb2)).
 > [Icinga Classic UI](#setting-up-icinga-classic-ui) does not use IDO as backend.
 
+### <a id="installing-database"></a> Installing the Database Server
+
+In order to use DB IDO you need to setup either [MySQL](#installing-database-mysql-server)
+or [PostgreSQL](#installing-database-postgresql-server) as supported database server.
+
+> **Note**
+>
+> It's up to you whether you choose to install it on the same server where Icinga 2 is running on,
+> or on a dedicated database host (or cluster).
+
+#### <a id="installing-database-mysql-server"></a> Installing MySQL database server
+
+Debian/Ubuntu:
+    # apt-get install mysql-server mysql-client
+
+RHEL/CentOS 5/6:
+    # yum install mysql-server mysql
+    # chkconfig mysqld on
+    # service mysqld start
+
+RHEL/CentOS 7 and Fedora 20 prefer MariaDB over MySQL:
+    # yum install mariadb-server mariadb
+    # systemctl enable mariadb.service
+    # systemctl start mariadb.service
+
+SUSE:
+    # zypper install mysql mysql-client
+    # chkconfig mysqld on
+    # service mysqld start
+
+RHEL based distributions do not automatically set a secure root password. Do that **now**:
+
+    # /usr/bin/mysql_secure_installation
+
+
+#### <a id="installing-database-postgresql-server"></a> Installing PostgreSQL database server
+
+Debian/Ubuntu:
+    # apt-get install postgresql
+
+RHEL/CentOS 5/6:
+    # yum install postgresql-server postgresql
+    # chkconfig postgresql on
+    # service postgresql start
+
+RHEL/CentOS 7 and Fedora 20 use [systemd](#systemd-service):
+    # yum install postgresql-server postgresql
+    # systemctl enable postgresql.service
+    # systemctl start postgresql.service
+
+SUSE:
+    # zypper install postgresql postgresql-server
+    # chkconfig postgresql on
+    # service postgresql start
+
 ### <a id="configuring-db-ido-mysql"></a> Configuring DB IDO MySQL
 
+> **Note**
+>
+> Upstream Debian packages provide a database configuration wizard by default.
+> You can skip the automated setup and install/upgrade the database manually
+> if you prefer that.
+
 #### <a id="setting-up-mysql-db"></a> Setting up the MySQL database
 
 First of all you have to install the `icinga2-ido-mysql` package using your
@@ -486,6 +608,7 @@ following command:
 
     # mysql -u root -p icinga < /usr/share/icinga2-ido-mysql/schema/mysql.sql
 
+
 #### <a id="upgrading-mysql-db"></a> Upgrading the MySQL database
 
 Check the `/usr/share/icinga2-ido-mysql/schema/upgrade` directory for an
@@ -513,11 +636,17 @@ You can enable the `ido-mysql` feature configuration file using `icinga2-enable-
 
 After enabling the ido-mysql feature you have to restart Icinga 2:
 
-    # /etc/init.d/icinga2 restart
+    # service icinga2 restart
 
 
 ### <a id="configuring-db-ido-postgresql"></a> Configuring DB IDO PostgreSQL
 
+> **Note**
+>
+> Upstream Debian packages provide a database configuration wizard by default.
+> You can skip the automated setup and install/upgrade the database manually
+> if you prefer that.
+
 #### Setting up the PostgreSQL database
 
 First of all you have to install the `icinga2-ido-pgsql` package using your
@@ -588,7 +717,7 @@ You can enable the `ido-pgsql` feature configuration file using `icinga2-enable-
 
 After enabling the ido-pgsql feature you have to restart Icinga 2:
 
-    # /etc/init.d/icinga2 restart
+    # service icinga2 restart
 
 
 ## <a id="setting-up-livestatus"></a> Setting up Livestatus
@@ -657,6 +786,40 @@ Special restrictions are noted specifically in the sections below.
 > Choose your preferred interface. There's no need to install [Classic UI](#setting-up-icinga-classic-ui)
 > if you prefer [Icinga Web](#setting-up-icinga-web) or [Icinga Web 2](#setting-up-icingaweb2) for example.
 
+### <a id="icinga2-user-interface-requirements"></a> Requirements
+
+* Web server (Apache2/Httpd, Nginx, Lighttp, etc)
+* User credentials
+* Firewall ports (tcp/80)
+
+The Debian, RHEL and SUSE packages for Icinga [Classic UI](#setting-up-icinga-classic-ui),
+[Web](#setting-up-icinga-web) and [Icingaweb 2](#setting-up-icingaweb2) depend on Apache2
+as web server.
+
+#### <a id="icinga2-user-interface-webserver"></a> Webserver
+
+Debian/Ubuntu packages will automatically fetch and install the required packages.
+
+RHEL/CentOS/Fedora:
+    # yum install httpd
+    # chkconfig httpd on && service httpd start
+    ## RHEL7
+    # systemctl enable httpd && systemctl start httpd
+
+SUSE:
+    # zypper install apache2
+    # chkconfig on && service apache2 start
+
+#### <a id="icinga2-user-interface-firewall-rules"></a> Firewall Rules
+
+Example:
+    # iptables -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
+    # service iptables save
+
+RHEL/CentOS 7 specific:
+    # firewall-cmd --add-service=http
+    # firewall-cmd --permanent --add-service=http
+
 ### <a id="setting-up-icinga-classic-ui"></a> Setting up Icinga Classic UI
 
 Icinga 2 can write `status.dat` and `objects.cache` files in the format that
@@ -672,7 +835,7 @@ the Classic UI using the following packages:
   Distribution  | Packages
   --------------|---------------------
   Debian        | icinga2-classicui
-  all others    | icinga2-classicui-config icinga-gui
+  RHEL/SUSE     | icinga2-classicui-config icinga-gui
 
 The Debian packages require additional packages which are provided by the
 [Debian Monitoring Project](http://www.debmon.org) (`DebMon`) repository.
@@ -810,14 +973,14 @@ please check the official [Icinga 1.x user interface documentation](http://docs.
 
 ### <a id="setting-up-icingaweb2"></a> Setting up Icinga Web 2
 
-Icinga Web 2 currently supports `status.dat`, `DB IDO`, or `Livestatus` as backends.
+Icinga Web 2 will support `status.dat`, `DB IDO`, or `Livestatus` as backends.
 
 Using DB IDO as backend, you need to install and configure the [DB IDO backend](#configuring-db-ido).
 Once finished, you can enable the feature for DB IDO MySQL:
 
     # icinga2-enable-feature ido-mysql
 
-furthermore [external commands](#external-commands) are supported through the external
+Furthermore [external commands](#external-commands) are supported through the external
 command pipe.
 
     # icinga2-enable-feature command
@@ -965,10 +1128,14 @@ The Icinga 2 `Systemd` service can be (re)started, reloaded, stopped and also qu
   restart             | The `restart` action is a shortcut for running the `stop` action followed by `start`.
   reload              | The `reload` action sends the `HUP` signal to Icinga 2 which causes it to restart. Unlike the `restart` action `reload` does not wait until Icinga 2 has restarted.
   status              | The `status` action checks if Icinga 2 is running.
+  enable              | The `enable` action enables the service being started at system boot time (similar to `chkconfig`)
 
 If you're stuck with configuration errors, you can manually invoke the [configuration validation](#config-validation).
 
+    # systemctl enable icinga2
 
+    # systemctl restart icinga2
+    Job for icinga2.service failed. See 'systemctl status icinga2.service' and 'journalctl -xn' for details.
 
 ### <a id="cmdline"></a> Command-line Options
 

doc/3-monitoring-basics.md

@@ -496,6 +496,22 @@ Icinga 2 will not check against any end time for this notification.
       assign where service.name == "ping4"
     }
 
+### <a id="disable-renotification"></a> Disable Re-notifications
+
+If you prefer to be notified only once, you can disable re-notifications by setting the
+`interval` attribute to `0`.
+
+    apply Notification "notify-once" to Service {
+      import "generic-notification"
+
+      command = "mail-notification"
+      users = [ "icingaadmin" ]
+
+      interval = 0 // disable re-notification
+
+      assign where service.name == "ping4"
+    }
+
 ### <a id="notification-filters-state-type"></a> Notification Filters by State and Type
 
 If there are no notification state and type filter attributes defined at the `Notification`
@@ -749,9 +765,11 @@ arguments. Each of them is optional by default and will be omitted if
 the value is not set. For example if the service calling the check command
 does not have `vars.http_port` set, it won't get added to the command
 line.
+
 If the `vars.http_ssl` custom attribute is set in the service, host or command
 object definition, Icinga 2 will add the `-S` argument based on the `set_if`
-option to the command line.
+numeric value to the command line. String values are not supported.
+
 That way you can use the `check_http` command definition for both, with and
 without SSL enabled checks saving you duplicated command definitions.
 
@@ -786,6 +804,9 @@ the `my-host2` host requires a different port on 2222. Both hosts are in the hos
 All hosts in the `my-linux-servers` hostgroup should get the `my-ssh` service applied based on an
 [apply rule](#apply). The optional `ssh_port` command argument should be inherited from the host
 the service is applied to. If not set, the check command `my-ssh` will omit the argument.
+The `host` argument is special: `skip_key` tells Icinga 2 to ignore the key, and directly put the
+value onto the command line. The `order` attribute specifies that this argument is the first one
+(`-1` is smaller than the other defaults).
 
     object CheckCommand "my-ssh" {
       import "plugin-check-command"

doc/6-configuring-icinga-2.md

@@ -26,6 +26,30 @@ EnableServiceChecks |**Read-write.** Whether active service checks are globally
 EnablePerfdata      |**Read-write.** Whether performance data processing is globally enabled. Defaults to true.
 UseVfork            |**Read-write.** Whether to use vfork(). Only available on *NIX. Defaults to true.
 
+## <a id="reserved-keywords"></a> Reserved Keywords
+
+These keywords are reserved by the configuration parser and must not be
+used as constants or custom attributes.
+
+    object
+    template
+    include
+    include_recursive
+    library
+    null
+    partial
+    true
+    false
+    const
+    apply
+    to
+    where
+    import
+    assign
+    ignore
+    zone
+    in
+
 
 ## <a id="configuration-syntax"></a> Configuration Syntax
 
@@ -583,13 +607,13 @@ Attributes:
   notes           |**Optional.** Notes for the host.
   notes_url       |**Optional.** Url for notes for the host (for example, in notification commands).
   action_url      |**Optional.** Url for actions for the host (for example, an external graphing tool).
-  icon_image      |**Optional.** Icon image for the host. Required for external interfaces only.
+  icon_image      |**Optional.** Icon image for the host. Used by external interfaces only.
-  icon_image_alt  |**Optional.** Icon image description for the host. Required for external interface only.
+  icon_image_alt  |**Optional.** Icon image description for the host. Used by external interface only.
 
 > **Best Practice**
 >
 > The `address` and `address6` attributes are required for running commands using
-> the `$address$` and `$address6` runtime macros.
+> the `$address$` and `$address6$` runtime macros.
 
 
 ### <a id="objecttype-hostgroup"></a> HostGroup
@@ -669,8 +693,8 @@ Attributes:
   notes           |**Optional.** Notes for the service.
   notes_url       |**Optional.** Url for notes for the service (for example, in notification commands).
   action_url      |**Optional.** Url for actions for the service (for example, an external graphing tool).
-  icon_image      |**Optional.** Icon image for the service. Required for external interfaces only.
+  icon_image      |**Optional.** Icon image for the service. Used by external interfaces only.
-  icon_image_alt  |**Optional.** Icon image description for the service. Required for external interface only.
+  icon_image_alt  |**Optional.** Icon image description for the service. Used by external interface only.
 
 
 Service objects have composite names, i.e. their names are based on the host_name attribute and the name you specified. This means
@@ -849,8 +873,16 @@ CheckCommand:
         description = "My plugin requires this argument for doing X."
         required = false    /* optional, no error if not set */
         skip_key = false    /* always use "-X <value>" */
-        set_if = "$have_x$" /* only set if variable defined */
+        set_if = "$have_x$" /* only set if variable defined and resolves to a numeric value. String values are not supported */
-        order = 0           /* first position */
+        order = -1          /* first position */
+      }
+      "-Y" = {
+        value = "$y_val$"
+        description = "My plugin requires this argument for doing Y."
+        required = false    /* optional, no error if not set */
+        skip_key = true     /* don't prefix "-Y" only use "<value>" */
+        set_if = "$have_y$" /* only set if variable defined and resolves to a numeric value. String values are not supported */
+        order = 0           /* second position */
       }
     }
 
@@ -860,9 +892,12 @@ CheckCommand:
   description | Optional argument description.
   required    | Required argument. Execution error if not set. Defaults to false (optional).
   skip_key    | Use the value as argument and skip the key.
-  set_if      | Argument added if value is set (macro resolves to a defined value).
+  set_if      | Argument is added if the macro resolves to a defined numeric value. String values are not supported.
   order       | Set if multiple arguments require a defined argument order.
 
+Argument order:
+    `..., -3, -2, -1, <un-ordered keys>, 1, 2, 3, ...`
+
 
 ### <a id="objecttype-notificationcommand"></a> NotificationCommand
 
@@ -971,7 +1006,7 @@ Attributes:
   user_groups               | **Optional.** A list of user group names who should be notified.
   times                     | **Optional.** A dictionary containing `begin` and `end` attributes for the notification.
   command                   | **Required.** The name of the notification command which should be executed when the notification is triggered.
-  interval                  | **Optional.** The notification interval (in seconds). This interval is used for active notifications. Defaults to 30 minutes.
+  interval                  | **Optional.** The notification interval (in seconds). This interval is used for active notifications. Defaults to 30 minutes. If set to 0, [re-notifications](#disable-renotification) are disabled.
   period                    | **Optional.** The name of a time period which determines when this notification should be triggered. Not set by default.
   types                     | **Optional.** A list of type filters when this notification should be triggered. By default everything is matched.
   states                    | **Optional.** A list of state filters when this notification should be triggered. By default everything is matched.

doc/8-migration.md

@@ -1244,6 +1244,17 @@ as array to the `command_line` attribute i.e. for better readability.
 It's also possible to define default custom attributes for the command itself which can be
 overridden by a service macro.
 
+#### <a id="differences-1x-2-commands-timeouts"></a> Command Timeouts
+
+In Icinga 1.x there were two global options defining a host and service check
+timeout. This was essentially bad when there only was a couple of check plugins
+requiring some command timeouts to be extended.
+
+Icinga 2 allows you to specify the command timeout directly on the command. So
+if your VMVware check plugin takes 15 minutes, [increase the timeout](#objecttype-checkcommand)
+accordingly.
+
+
 ### <a id="differences-1x-2-groups"></a> Groups
 
 In Icinga 2 hosts, services and users are added to groups using the `groups`