Documentation: Add development section.

Fixes #6184

doc/8-development.md

@@ -0,0 +1,91 @@
+# <a id="icinga-2-development"></a> Icinga 2 Development
+
+You can follow Icinga 2's development closely by checking
+out these resources:
+
+* Development Bug Tracker: [https://dev.icinga.org/projects/i2?jump=issues] ([How to report a bug](http://www.icinga.org/faq/how-to-report-a-bug/))
+* Git Repositories: [https://git.icinga.org/?p=icinga2.git;a=summary] (mirror at [https://github.com/Icinga/icinga2])
+* Git Checkins Mailinglist: [https://lists.icinga.org/mailman/listinfo/icinga-checkins]
+* Development Mailinglist: [https://lists.icinga.org/mailman/listinfo/icinga-devel]
+* #icinga-devel on irc.freenode.net [http://webchat.freenode.net/?channels=icinga-devel] including a Git Commit Bot
+
+For general support questions, please refer to [https://www.icinga.org/support/].
+
+
+## <a id="development-debug"></a> Debug Icinga 2
+
+Make sure that the debug symbols are available for Icinga 2.
+The Icinga 2 packages provide a debug package which must be
+installed seperately for all involved binaries, like `icinga2-bin`
+or `icinga2-ido-mysql`.
+
+    # yum install icinga2-bin-debuginfo icinga2-ido-mysql-debuginfo
+
+Compiled binaries require the `-DCMAKE_BUILD_TYPE=RelWithDebInfo` or
+`-DCMAKE_BUILD_TYPE=Debug` cmake build flags.
+
+### <a id="development-debug-gdb"></a> GDB
+
+Call GDB with the binary and all arguments and run it in foreground.
+
+    # gdb --args /usr/sbin/icinga2 -c /etc/icinga2/icinga2.conf -x
+
+### <a id="development-debug-gdb-run"></a> GDB Run
+
+Run the application.
+
+    (gdb) r
+
+Kill the running application.
+
+    (gdb) k
+
+Continue after breakpoint.
+
+    (gdb) c
+
+### <a id="development-debug-gdb-backtrace"></a> GDB Backtrace
+
+If Icinga 2 aborted its operation abnormally, generate a backtrace.
+
+    (gdb) bt
+    (gdb) bt full
+
+>**Tip**
+>
+> If you're opening an issue at [https://dev.icinga.org] make sure
+> to attach as much details as possible.
+
+
+### <a id="development-debug-gdb-backtrace-stepping"></a> GDB Backtrace Stepping
+
+Identifying the problem may require stepping into the backtrace analysing
+the current scope, attributes and possible unmet requirements. `p` prints
+the value of the selected variable or function call result, if applicable.
+
+    (gdb) up
+    (gdb) down
+    (gdb) p checkable
+    (gdb) p checkable-GetName()
+
+
+### <a id="development-debug-gdb-breakpoint"></a> GDB Breakpoints
+
+Set a breakpoint to a specific function call, or file specific line.
+
+    (gdb) b checkable.cpp:125
+    (gdb) b icinga::Checkable::SetEnablePerfdata
+
+GDB will ask about loading the required symbols later, select `yes` instead
+of `no`.
+
+Then run Icinga 2 until it reaches the first breakpoint. Continue with `c`
+afterwards.
+
+    (gdb) run
+    (gdb) c
+
+If you want to delete all breakpoints, use `d` and select `yes`.
+
+    (gdb) d
+