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diff --git a/docs/contributing/debugging.rst b/docs/contributing/debugging.rst deleted file mode 100644 index a4c73d15..00000000 --- a/docs/contributing/debugging.rst +++ /dev/null @@ -1,151 +0,0 @@ -.. _debugging: - -######### -Debugging -######### - -There are two flags available to aid in debugging configuration scripts. -Since configuration loading issues will manifest during boot, the flags are -passed as kernel boot parameters. - -System Startup -============== - -The system startup can be debugged (like loading in the configuration -file from ``/config/config.boot``. This can be achieve by extending the -Kernel command-line in the bootloader. - -Kernel ------- - -* ``vyos-debug`` - Adding the parameter to the linux boot line will produce - timing results for the execution of scripts during commit. If one is seeing - an unexpected delay during manual or boot commit, this may be useful in - identifying bottlenecks. The internal flag is ``VYOS_DEBUG``, and is found - in vyatta-cfg_. Output is directed to ``/var/log/vyatta/cfg-stdout.log``. - -* ``vyos-config-debug`` - During development, coding errors can lead to a - commit failure on boot, possibly resulting in a failed initialization of the - CLI. In this circumstance, the kernel boot parameter ``vyos-config-debug`` - will ensure access to the system as user ``vyos``, and will log a Python - stack trace to the file ``/tmp/boot-config-trace``. - File ``boot-config-trace`` will generate only if config loaded with a failure status. - -Live System -=========== - -A number of flags can be set up to change the behaviour of VyOS at runtime. -These flags can be toggled using either environment variables or creating -files. - -For each feature, a file called ``vyos.feature.debug`` can be created to -toggle the feature on. If a parameter is required it can be placed inside -the file as its first line. - -The file can be placed in ``/tmp`` for one time debugging (as the file -will be removed on reboot) or placed in '/config' to stay permanently. - -For example, ``/tmp/vyos.ifconfig.debug`` can be created to enable -interface debugging. - -It is also possible to set up the debugging using environment variables. -In that case, the name will be (in uppercase) VYOS_FEATURE_DEBUG. - -For example running, ``export VYOS_IFCONFIG_DEBUG=""`` on your vbash, -will have the same effect as ``touch /tmp/vyos.ifconfig.debug``. - -* ``ifconfig`` - Once set, all commands used, and their responses received - from the OS, will be presented on the screen for inspection. - -* ``command`` - Once set, all commands used, and their responses received - from the OS, will be presented on the screen for inspection. - -* ``developer`` - Should a command fail, instead of printing a message to the - user explaining how to report issues, the python interpreter will start a - PBD post-mortem session to allow the developer to debug the issue. As the - debugger will wait from input from the developer, it has the capacity to - prevent a router to boot and therefore should only be permanently set up - on production if you are ready to see the OS fail to boot. - -* ``log`` - In some rare cases, it may be useful to see what the OS is doing, - including during boot. This option sends all commands used by VyOS to a - file. The default file is ``/tmp/full-log`` but it can be changed. - -.. note:: In order to retrieve the debug output on the command-line you need to - disable ``vyos-configd`` in addition. This can be run either one-time by calling - ``sudo systemctl stop vyos-configd`` or make this reboot-safe by calling - ``sudo systemctl disable vyos-configd``. - -Config Migration Scripts ------------------------- - -When writing a new configuration migrator it may happen that you see an error -when you try to invoke it manually on a development system. This error will -look like: - -.. code-block:: none - - vyos@vyos:~$ /opt/vyatta/etc/config-migrate/migrate/ssh/0-to-1 /tmp/config.boot - Traceback (most recent call last): - File "/opt/vyatta/etc/config-migrate/migrate/ssh/0-to-1", line 31, in <module> - config = ConfigTree(config_file) - File "/usr/lib/python3/dist-packages/vyos/configtree.py", line 134, in __init__ - raise ValueError("Failed to parse config: {0}".format(msg)) - ValueError: Failed to parse config: Syntax error on line 240, character 1: Invalid syntax. - -The reason is that the configuration migration backend is rewritten and uses -a new form of "magic string" which is applied on demand when real config -migration is run on boot. When runnint individual migrators for testing, -you need to convert the "magic string" on your own by: - -.. code-block:: none - - vyos@vyos:~$ /usr/libexec/vyos/run-config-migration.py --virtual --set-vintage vyos /tmp/config.boot - -Configuration Error on System Boot ----------------------------------- - -Beeing brave and running the latest rolling releases will sometimes trigger -bugs due to corner cases we missed in our design. Those bugs should be filed -via Phabricator_ but you can help us to narrow doen the issue. Login to your -VyOS system and change into configuration mode by typing ``configure``. Now -re-load your boot configuration by simply typing ``load`` followed by return. - -You shoudl now see a Python backtrace which will help us to handle the issue, -please attach it to the Phabricator_ task. - -Boot Timing ------------ - -During the migration and extensive rewrite of functionality from Perl into -Python a significant increase in the overall system boottime was noticed. The -system boot time can be analysed and a graph can be generated in the end which -shows in detail who called whom during the system startup phase. - -This is done by utilizing the ``systemd-bootchart`` package which is now -installed by default on the VyOS 1.3 (equuleus) branch. The configuration is -also versioned so we get comparable results. ``systemd-bootchart`` is configured -using this file: bootchart.conf_ - -To enable boot time graphing change the Kernel commandline and add the folowing -string: ``init=/usr/lib/systemd/systemd-bootchart`` - -This can also be done permanently by changing ``/boot/grub/grub.cfg``. - -Priorities -========== - -VyOS CLI is all about priorities. Every CLI node has a corresponding ``node.def`` -file and possibly an attached script that is executed when the node is present. -Nodes can have a priority, and on system bootup - or any other ``commit`` to the -config all scripts are executed from lowest to higest priority. This is good as -this gives a deterministic behavior. - -To debug issues in priorities or to see what's going on in the background you can -use the ``/opt/vyatta/sbin/priority.pl`` script which lists to you the execution -order of the scripts. - -.. _vyatta-cfg: https://github.com/vyos/vyatta-cfg -.. _bootchart.conf: https://github.com/vyos/vyos-build/blob/current/data/live-build-config/includes.chroot/etc/systemd/bootchart.conf - -.. include:: /_include/common-references.txt |