9.1 KiB
Develop Icinga 2
This chapter provides hints on Icinga 2 development especially for debugging purposes.
Note
If you are planning to build your own development environment, please consult the
INSTALL.mdfile from the source tree.
Debug Requirements
Make sure that the debug symbols are available for Icinga 2.
The Icinga 2 packages provide a debug package which must be
installed separately for all involved binaries, like icinga2-bin
or icinga2-ido-mysql.
Debian/Ubuntu:
# apt-get install icinga2-dbg
RHEL/CentOS:
# yum install icinga2-debuginfo
SLES/openSUSE:
# zypper install icinga2-bin-debuginfo icinga2-ido-mysql-debuginfo
Furthermore, you may also have to install debug symbols for Boost and your C library.
If you're building your own binaries, you should use the -DCMAKE_BUILD_TYPE=Debug cmake
build flag for debug builds.
GDB
Install gdb:
Debian/Ubuntu:
# apt-get install gdb
RHEL/CentOS/Fedora:
# yum install gdb
SLES/openSUSE:
# zypper install gdb
Install the boost, python and icinga2 pretty printers. Absolute paths are required,
so please make sure to update the installation paths accordingly (pwd).
$ mkdir -p ~/.gdb_printers && cd ~/.gdb_printers
Boost Pretty Printers compatible with Python 3:
$ git clone https://github.com/mateidavid/Boost-Pretty-Printer.git && cd Boost-Pretty-Printer
$ git checkout python-3
$ pwd
/home/michi/.gdb_printers/Boost-Pretty-Printer
Python Pretty Printers:
$ cd ~/.gdb_printers
$ svn co svn://gcc.gnu.org/svn/gcc/trunk/libstdc++-v3/python
Icinga 2 Pretty Printers:
$ mkdir -p ~/.gdb_printers/icinga2 && cd ~/.gdb_printers/icinga2
$ wget https://raw.githubusercontent.com/Icinga/icinga2/master/tools/debug/gdb/icingadbg.py
Now you'll need to modify/setup your ~/.gdbinit configuration file.
You can download the one from Icinga 2 and modify all paths.
Example on Fedora 22:
$ wget https://raw.githubusercontent.com/Icinga/icinga2/master/tools/debug/gdb/gdbinit -O ~/.gdbinit
$ vim ~/.gdbinit
set print pretty on
python
import sys
sys.path.insert(0, '/home/michi/.gdb_printers/icinga2')
from icingadbg import register_icinga_printers
register_icinga_printers()
end
python
import sys
sys.path.insert(0, '/home/michi/.gdb_printers/python')
from libstdcxx.v6.printers import register_libstdcxx_printers
try:
register_libstdcxx_printers(None)
except:
pass
end
python
import sys
sys.path.insert(0, '/home/michi/.gdb_printers/Boost-Pretty-Printer')
import boost_print
boost_print.register_printers()
end
If you are getting the following error when running gdb, the libstdcxx
printers are already preloaded in your environment and you can remove
the duplicate import in your ~/.gdbinit file.
RuntimeError: pretty-printer already registered: libstdc++-v6
GDB Run
Call GDB with the binary (/usr/sbin/icinga2 is a wrapper script calling
/usr/lib64/icinga2/sbin/icinga2 since 2.4) and all arguments and run it in foreground.
# gdb --args /usr/lib64/icinga2/sbin/icinga2 daemon -x debug --no-stack-rlimit
The exact path to the Icinga 2 binary differs on each distribution. On Ubuntu
it is installed into /usr/lib/x86_64-linux-gnu/icinga2/sbin/icinga2 on 64-bit systems
for example.
Note
If gdb tells you it's missing debug symbols, quit gdb and install them:
Missing separate debuginfos, use: debuginfo-install ...
Run the application.
(gdb) r
Kill the running application.
(gdb) k
Continue after breakpoint.
(gdb) c
GDB Core Dump
Either attach to the running process using gdb -p PID or start
a new gdb run.
(gdb) r
(gdb) generate-core-file
GDB Backtrace
If Icinga 2 aborted its operation abnormally, generate a backtrace.
(gdb) bt
(gdb) thread apply all bt full
If gdb stops at a SIGPIPE signal please disable the signal before running Icinga 2.
(gdb) handle SIGPIPE nostop noprint pass
(gdb) r
If you create a bug report, make sure to attach as much detail as possible.
GDB Backtrace from Running Process
If Icinga 2 is still running, generate a full backtrace from the running process and store it into a new file (e.g. for debugging dead locks):
# gdb -p $(pidof icinga2) -batch -ex "thread apply all bt full" -ex "detach" -ex "q" > gdb_bt.log
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.
(gdb) up
(gdb) down
(gdb) p checkable
(gdb) p checkable.px->m_Name
GDB Breakpoints
To 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
Tip
When debugging exceptions, set your breakpoint like this:
b __cxa_throw.
Breakpoint Example:
(gdb) b __cxa_throw
(gdb) r
(gdb) up
....
(gdb) up
#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)
at /home/michi/coding/icinga/icinga2/lib/base/utility.cpp:609
609 callback(cpath);
(gdb) l
604
605 #endif /* _WIN32 */
606
607 std::sort(files.begin(), files.end());
608 BOOST_FOREACH(const String& cpath, files) {
609 callback(cpath);
610 }
611
612 std::sort(dirs.begin(), dirs.end());
613 BOOST_FOREACH(const String& cpath, dirs) {
(gdb) p files
$3 = std::vector of length 11, capacity 16 = {{static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/agent.conf"}, {static NPos = 18446744073709551615,
m_Data = "/etc/icinga2/conf.d/commands.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/downtimes.conf"}, {static NPos = 18446744073709551615,
m_Data = "/etc/icinga2/conf.d/groups.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/notifications.conf"}, {static NPos = 18446744073709551615,
m_Data = "/etc/icinga2/conf.d/satellite.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/services.conf"}, {static NPos = 18446744073709551615,
m_Data = "/etc/icinga2/conf.d/templates.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/test.conf"}, {static NPos = 18446744073709551615,
m_Data = "/etc/icinga2/conf.d/timeperiods.conf"}, {static NPos = 18446744073709551615, m_Data = "/etc/icinga2/conf.d/users.conf"}}
Core Dump
When the Icinga 2 daemon crashes with a SIGSEGV signal
a core dump file should be written. This will help
developers to analyze and fix the problem.
Core Dump File Size Limit
This requires setting the core dump file size to unlimited.
Example for Systemd:
vim /usr/lib/systemd/system/icinga2.service
[Service]
...
LimitCORE=infinity
systemctl daemon-reload
systemctl restart icinga2
Example for init script:
vim /etc/init.d/icinga2
...
ulimit -c unlimited
service icinga2 restart
Verify that the Icinga 2 process core file size limit is set to unlimited.
cat /proc/`pidof icinga2`/limits
...
Max core file size unlimited unlimited bytes
Core Dump Kernel Format
The Icinga 2 daemon runs with the SUID bit set. Therefore you need to explicitly enable core dumps for SUID on Linux.
sysctl -w fs.suid_dumpable=1
Adjust the coredump kernel format and file location on Linux:
sysctl -w kernel.core_pattern=/var/lib/cores/core.%e.%p
install -m 1777 -d /var/lib/cores
MacOS:
sysctl -w kern.corefile=/cores/core.%P
chmod 777 /cores
Core Dump Analysis
Once Icinga 2 crashes again a new coredump file will be written. Please attach this file to your bug report in addition to the general details.
Simple test case for a SIGSEGV simulation with sleep:
ulimit -c unlimited
sleep 1800&
[1] <PID>
kill -SEGV <PID>
gdb `which sleep` /var/lib/cores/core.sleep.<PID>
(gdb) bt
rm /var/lib/cores/core.sleep.*
Analyzing Icinga 2:
gdb /usr/lib64/icinga2/sbin/icinga2 core.icinga2.<PID>
(gdb) bt