1 # Develop Icinga 2 <a id="development"></a>
3 This chapter provides hints on Icinga 2 development
4 especially for debugging purposes.
8 > If you are planning to build your own development environment,
9 > please consult the `INSTALL.md` file from the source tree.
11 ## Debug Requirements <a id="debug-requirements"></a>
13 Make sure that the debug symbols are available for Icinga 2.
14 The Icinga 2 packages provide a debug package which must be
15 installed separately for all involved binaries, like `icinga2-bin`
16 or `icinga2-ido-mysql`.
20 # apt-get install icinga2-dbg
24 # yum install icinga2-debuginfo
28 # dnf install icinga2-debuginfo icinga2-bin-debuginfo icinga2-ido-mysql-debuginfo
32 # zypper install icinga2-bin-debuginfo icinga2-ido-mysql-debuginfo
35 Furthermore, you may also have to install debug symbols for Boost and your C library.
37 If you're building your own binaries, you should use the `-DCMAKE_BUILD_TYPE=Debug` cmake
38 build flag for debug builds.
41 ## GDB <a id="development-debug-gdb"></a>
58 Install the `boost`, `python` and `icinga2` pretty printers. Absolute paths are required,
59 so please make sure to update the installation paths accordingly (`pwd`).
61 $ mkdir -p ~/.gdb_printers && cd ~/.gdb_printers
63 Boost Pretty Printers compatible with Python 3:
65 $ git clone https://github.com/mateidavid/Boost-Pretty-Printer.git && cd Boost-Pretty-Printer
66 $ git checkout python-3
68 /home/michi/.gdb_printers/Boost-Pretty-Printer
70 Python Pretty Printers:
73 $ svn co svn://gcc.gnu.org/svn/gcc/trunk/libstdc++-v3/python
75 Icinga 2 Pretty Printers:
77 $ mkdir -p ~/.gdb_printers/icinga2 && cd ~/.gdb_printers/icinga2
78 $ wget https://raw.githubusercontent.com/Icinga/icinga2/master/tools/debug/gdb/icingadbg.py
80 Now you'll need to modify/setup your `~/.gdbinit` configuration file.
81 You can download the one from Icinga 2 and modify all paths.
85 $ wget https://raw.githubusercontent.com/Icinga/icinga2/master/tools/debug/gdb/gdbinit -O ~/.gdbinit
92 sys.path.insert(0, '/home/michi/.gdb_printers/icinga2')
93 from icingadbg import register_icinga_printers
94 register_icinga_printers()
99 sys.path.insert(0, '/home/michi/.gdb_printers/python')
100 from libstdcxx.v6.printers import register_libstdcxx_printers
102 register_libstdcxx_printers(None)
109 sys.path.insert(0, '/home/michi/.gdb_printers/Boost-Pretty-Printer')
111 boost_print.register_printers()
115 If you are getting the following error when running gdb, the `libstdcxx`
116 printers are already preloaded in your environment and you can remove
117 the duplicate import in your `~/.gdbinit` file.
119 RuntimeError: pretty-printer already registered: libstdc++-v6
121 ### GDB Run <a id="development-debug-gdb-run"></a>
123 Call GDB with the binary (`/usr/sbin/icinga2` is a wrapper script calling
124 `/usr/lib64/icinga2/sbin/icinga2` since 2.4) and all arguments and run it in foreground.
126 # gdb --args /usr/lib64/icinga2/sbin/icinga2 daemon -x debug --no-stack-rlimit
128 The exact path to the Icinga 2 binary differs on each distribution. On Ubuntu
129 it is installed into `/usr/lib/x86_64-linux-gnu/icinga2/sbin/icinga2` on 64-bit systems
134 > If gdb tells you it's missing debug symbols, quit gdb and install
135 > them: `Missing separate debuginfos, use: debuginfo-install ...`
141 Kill the running application.
145 Continue after breakpoint.
149 ### GDB Core Dump <a id="development-debug-gdb-coredump"></a>
151 Either attach to the running process using `gdb -p PID` or start
155 (gdb) generate-core-file
157 ### GDB Backtrace <a id="development-debug-gdb-backtrace"></a>
159 If Icinga 2 aborted its operation abnormally, generate a backtrace.
162 (gdb) thread apply all bt full
164 If gdb stops at a SIGPIPE signal please disable the signal before
167 (gdb) handle SIGPIPE nostop noprint pass
170 If you create a [bug report](https://www.icinga.com/community/get-involved/),
171 make sure to attach as much detail as possible.
173 ### GDB Backtrace from Running Process <a id="development-debug-gdb-backtrace-running"></a>
175 If Icinga 2 is still running, generate a full backtrace from the running
176 process and store it into a new file (e.g. for debugging dead locks):
178 Icinga 2 runs with 2 processes, therefore generate two backtrace logs
179 and add them to the GitHub issue.
182 for pid in $(pidof icinga2); do gdb -p $pid -batch -ex "thread apply all bt full" -ex "detach" -ex "q" > gdb_bt_${pid}_`date +%s`.log; done
185 ### GDB Thread List from Running Process <a id="development-debug-gdb-thread-list-running"></a>
187 Instead of a full backtrace, you sometimes just need a list of running threads.
190 for pid in $(pidof icinga2); do gdb -p $pid -batch -ex "info threads" -ex "detach" -ex "q" > gdb_threads_${pid}_`date +%s`.log; done
193 ### GDB Backtrace Stepping <a id="development-debug-gdb-backtrace-stepping"></a>
195 Identifying the problem may require stepping into the backtrace, analysing
196 the current scope, attributes, and possible unmet requirements. `p` prints
197 the value of the selected variable or function call result.
202 (gdb) p checkable.px->m_Name
205 ### GDB Breakpoints <a id="development-debug-gdb-breakpoint"></a>
207 To set a breakpoint to a specific function call, or file specific line.
209 (gdb) b checkable.cpp:125
210 (gdb) b icinga::Checkable::SetEnablePerfdata
212 GDB will ask about loading the required symbols later, select `yes` instead
215 Then run Icinga 2 until it reaches the first breakpoint. Continue with `c`
221 If you want to delete all breakpoints, use `d` and select `yes`.
227 > When debugging exceptions, set your breakpoint like this: `b __cxa_throw`.
236 #11 0x00007ffff7cbf9ff in icinga::Utility::GlobRecursive(icinga::String const&, icinga::String const&, boost::function<void (icinga::String const&)> const&, int) (path=..., pattern=..., callback=..., type=1)
237 at /home/michi/coding/icinga/icinga2/lib/base/utility.cpp:609
241 605 #endif /* _WIN32 */
243 607 std::sort(files.begin(), files.end());
244 608 BOOST_FOREACH(const String& cpath, files) {
248 612 std::sort(dirs.begin(), dirs.end());
249 613 BOOST_FOREACH(const String& cpath, dirs) {
251 $3 = std::vector of length 11, capacity 16 = {{static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/agent.conf"}, {static NPos = 18446744073709551615,
252 m_Data = "/etc/icinga2/conf.d/commands.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/downtimes.conf"}, {static NPos = 18446744073709551615,
253 m_Data = "/etc/icinga2/conf.d/groups.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/notifications.conf"}, {static NPos = 18446744073709551615,
254 m_Data = "/etc/icinga2/conf.d/satellite.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/services.conf"}, {static NPos = 18446744073709551615,
255 m_Data = "/etc/icinga2/conf.d/templates.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/test.conf"}, {static NPos = 18446744073709551615,
256 m_Data = "/etc/icinga2/conf.d/timeperiods.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/users.conf"}}
259 ## Core Dump <a id="development-debug-core-dump"></a>
261 When the Icinga 2 daemon crashes with a `SIGSEGV` signal
262 a core dump file should be written. This will help
263 developers to analyze and fix the problem.
265 ### Core Dump File Size Limit <a id="development-debug-core-dump-limit"></a>
267 This requires setting the core dump file size to `unlimited`.
271 vim /usr/lib/systemd/system/icinga2.service
277 systemctl daemon-reload
279 systemctl restart icinga2
281 Example for init script:
283 vim /etc/init.d/icinga2
287 service icinga2 restart
289 Verify that the Icinga 2 process core file size limit is set to `unlimited`.
291 cat /proc/`pidof icinga2`/limits
293 Max core file size unlimited unlimited bytes
296 ### Core Dump Kernel Format <a id="development-debug-core-dump-format"></a>
298 The Icinga 2 daemon runs with the SUID bit set. Therefore you need
299 to explicitly enable core dumps for SUID on Linux.
301 sysctl -w fs.suid_dumpable=1
303 Adjust the coredump kernel format and file location on Linux:
305 sysctl -w kernel.core_pattern=/var/lib/cores/core.%e.%p
307 install -m 1777 -d /var/lib/cores
311 sysctl -w kern.corefile=/cores/core.%P
315 ### Core Dump Analysis <a id="development-debug-core-dump-analysis"></a>
317 Once Icinga 2 crashes again a new coredump file will be written. Please
318 attach this file to your bug report in addition to the general details.
320 Simple test case for a `SIGSEGV` simulation with `sleep`:
326 gdb `which sleep` /var/lib/cores/core.sleep.<PID>
328 rm /var/lib/cores/core.sleep.*
332 gdb /usr/lib64/icinga2/sbin/icinga2 core.icinga2.<PID>