docs: add migration/compat basics

docs/.gitignore

@@ -1,12 +1,5 @@
 Doxyfile
 icinga2.html
-icinga2-intro.html
+icinga2-*.html
-icinga2-config.html
-icinga2-config-syntax.html
-icinga2-config-types.html
-icinga2-tutorial.html
-icinga2-main.html
-icinga2-install.html
-icinga2-config.xml
 icinga2.8
 .directory

docs/Makefile.am

@@ -2,6 +2,7 @@
 
 EXTRA_DIST = \
 	icinga2.adoc \
+	icinga2-compat.adoc \
 	icinga2-config.adoc \
 	icinga2-config-syntax.adoc \
 	icinga2-config-types.adoc \
@@ -9,6 +10,7 @@ EXTRA_DIST = \
 	icinga2-intro.adoc \
 	icinga2-tutorial.adoc \
 	icinga2-main.adoc \
+	icinga2-migration.adoc \
 	icinga2.8
 
 icinga2docdir = ${docdir}
@@ -22,13 +24,15 @@ man8_MANS = \
 if AD_COND_doc
 icinga2doc_DATA += \
 	icinga2.html \
+	icinga2-compat.html \
 	icinga2-config.html \
 	icinga2-config-syntax.html \
 	icinga2-config-types.html \
 	icinga2-install.html \
 	icinga2-intro.html \
 	icinga2-tutorial.html \
-	icinga2-main.html
+	icinga2-main.html \
+	icinga2-migration.html
 
 .adoc.html:
 	$(AD_ENV) $(AD_ASCIIDOC) -a toc -a numbered -o $@ $<

docs/icinga2-compat.adoc

@@ -0,0 +1,126 @@
+Icinga 2 Compatibility
+======================
+
+:keywords:	Icinga, documentation, migration
+:description:	Icinga 2 Migration
+
+Purpose
+-------
+
+Documentation on the compatibility and changes introduced with Icinga 2.
+
+
+Introduction
+------------
+
+Unlike Icinga 1.x, all used components (not only those for compatibility) run
+asynchronous and use queues, if required. That way Icinga 2 does not get blocked
+by any event, action or execution.
+
+Configuration
+-------------
+
+NOTE: If you are upgrading from Icinga 1.x (or Nagios 3.x+) please note that
+Icinga 2 introduces a new configuration format.
+
+Details on the configuration can be found in chapter link::icinga2-config.html[Configuration]
+
+Icinga 2 ships a config conversion script which will help you migrating the
+existing configuration into the new format. Please look into the
+'tools/configconvert' directory and follow the 'README' instructions.
+
+TIP: If you kept planning to clean up your existing configuration, it may be a
+good shot to start fresh with a new configuration strategy based on the Icinga 2
+configuration logic.
+
+Check Plugins
+-------------
+
+All native check plugins can be used with Icinga 2. The configuration of check
+commands is changed due to the new configuration format.
+
+Classic status and log files
+----------------------------
+
+Icinga 2 will write status.dat and objects.cache in a given interval like known
+from Icinga 1.x - including the logs and their archives in the old format and
+naming syntax. That way you can point any existing Classic UI installation to
+the new locations (or any other addon/plugin using them).
+
+External Commands
+-----------------
+
+Like known from Icinga 1.x, Icinga 2 also provides an external command pipe
+allowing your scripts and guis to send commands to the core triggering various
+actions.
+
+Some commands are not supported though as their triggered functionality is not
+available in Icinga 2 anymore.
+
+For a detailed list, please check: https://wiki.icinga.org/display/icinga2/External+Commands
+
+
+Performance Data
+----------------
+
+The Icinga 1.x Plugin API defines the performance data format. Icinga 2 parses
+the check output accordingly and writes performance data files based on template
+macros. File rotation interval can be defined as well.
+
+Unlike Icinga 1.x you can define multiple performance data writers for all your
+graphing addons such as PNP, inGraph or graphite.
+
+
+IDO DB
+------
+
+Icinga 1.x uses an addon called 'IDOUtils' to store core configuration, status
+and historical information in a database schema. Icinga Web and Reporting are
+using that database as their chosen backend.
+
+Icinga 2 is compatible to the IDO db schema but the the underlaying design of
+inserting, updating and deleting data is different - asynchronous queueing,
+database transactions and optimized queries for performance.
+
+Furthermore there is no seperated daemon to receive the data through a socket.
+Instead the IDO component queues the data and writes directly into the database
+using the native database driver library (e.g. libmysqlclient). Unlike Icinga
+1.x libdbi as db abstraction layer is not used anymore.
+
+
+Livestatus
+----------
+
+Icinga 2 supports the livestatus api while using Icinga 1.x an addon named
+'mk_livestatus' was required.
+
+Next to the GET functionality for retrieving configuration, status and
+historical data, Icinga 2 livestatus also supports the COMMANDS functionality.
+
+TIP: Icinga 2 supports tcp sockets natively while the Icinga 1.x addon only
+provides unix socket support.
+
+Checkresult Reaper
+------------------
+
+Unlike Icinga 1.x Icinga 2 is a multithreaded application and processes check
+results in memory. The old checkresult reaper reading files from disk again is
+obviously not required anymore for native checks.
+
+Some popular addons have been injecting their checkresults into the Icinga 1.x
+checkresult spool directory bypassing the external command pipe and
+PROCESS_SERVICE_CHECK_RESULT mainly for performance reasons.
+
+In order to support that functionality as well, Icinga 2 got its optional
+checkresult reaper.
+
+Changes
+-------
+
+This is a collection of known changes in behaviour, configuration and outputs.
+
+NOTE: May be incomplete, and requires updates in the future.
+
+TODO
+
+/* vim: set syntax=asciidoc filetype=asciidoc: */

docs/icinga2-migration.adoc

@@ -0,0 +1,39 @@
+Icinga 2 Migration
+==================
+
+:keywords:	Icinga, documentation, migration
+:description:	Icinga 2 Migration
+
+Purpose
+-------
+
+Documentation on the general migration from Icinga 1.x to Icinga 2.
+
+Requirements
+------------
+
+Multi-core cpu, ram, fast disks.
+
+Installation
+------------
+
+Icinga 1.x and Icinga 2 may run side by side, but it's recommended to backup
+your existing 1.x installation before installing Icinga 2 on the same host.
+
+Compatibility
+-------------
+
+NOTE: The configuration format changed from 1.x to 2.x. Don't panic though.
+A conversion script is shipped in 'tools/configconvert' - please check the
+'README' file.
+
+For details check the chapter link:icinga2-compat.html[Compatibility].
+
+Changes
+-------
+
+For details check the chapter link:icinga2-compat.html[Changes].
+
+TODO
+
+/* vim: set syntax=asciidoc filetype=asciidoc: */

docs/icinga2.adoc

@@ -16,6 +16,12 @@ include::icinga2-intro.adoc[]
 :leveloffset: 1
 include::icinga2-install.adoc[]
 
+:leveloffset: 1
+include::icinga2-migration.adoc[]
+
+:leveloffset: 1
+include::icinga2-compat.adoc[]
+
 :leveloffset: 1
 include::icinga2-tutorial.adoc[]