Re: [systemd-devel] Support for pre-restart check
On 07/31/2014 12:41 AM, Michael Biebl wrote: 2014-07-30 14:34 GMT+02:00 Reindl Harald h.rei...@thelounge.net: ExecStopPre would be better suited as the pre-restart check because it would achieve the goal and also prevent stop a service until it's configuration is fixed - that catchs cases where you stop something for whatever reason and expect it would be started at the next boot I don't think that would be a wise thing to do. If I want to reboot my system, it shouldn't fail to reboot because of a buggy apache configuration. Apache should shutdown and simply fail to start on next reboot. Right the solution to this cannot interfere with normal starting and shutdown and wont be solve with introducing yet another Exec* line in one form or another. What is needed to solve this problem ( as in to reliably restart an application ) as far as I can tell is to introduce something like pre restart check which tries to start another instance of the service in an isolated application container, returns true if successful, is enabled per service, perhaps could be extended per container as well and only executed when systemctl restart/reload ( or implemented in try-restart ) $foo is run. Providing patches for anything less then what I mention here above is a waste of time from my point of view since it wont solve the underlying problem. JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Am 31.07.2014 um 07:03 schrieb Jóhann B. Guðmundsson: On 07/31/2014 12:16 AM, Colin Guthrie wrote: I think the use case is pretty clear tho'. Config (or general machine state) has transitioned from working to broken in the time since the service was started and while it's really not a nice situation to find yourself in (relying on a running service not crashng!), this at least helps avoid nasty consequences for the most part while you work to fix things. The use case administrator want, is fixing their own lazyness and incompetence not having to run the configuration syntax checker by hand after they made changes to the configuration for one of those handful of daemon/service that actually come with those. strange attitude calling safety lazyness and incompetence given that you can throw away a lot of things developed in the past 10 years to support the user in many different areas of IT signature.asc Description: OpenPGP digital signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Am 31.07.2014 um 02:41 schrieb Michael Biebl: 2014-07-30 14:34 GMT+02:00 Reindl Harald h.rei...@thelounge.net: ExecStopPre would be better suited as the pre-restart check because it would achieve the goal and also prevent stop a service until it's configuration is fixed - that catchs cases where you stop something for whatever reason and expect it would be started at the next boot I don't think that would be a wise thing to do. If I want to reboot my system, it shouldn't fail to reboot because of a buggy apache configuration it could simply called and failing ignored in that case systemd knows that the system is at sthut down Apache should shutdown and simply fail to start on next reboot in that case yes Am 31.07.2014 um 02:16 schrieb Colin Guthrie: Reindl Harald wrote on 30/07/14 13:34: *how* should that both help in calling apachectl -t *before* stop the service and in case of a error-repsonse keep it running? Note, just for clarity, you don't really want to run such a config test when explicitly stopping a service i do want that in case it ends in a state where i can't start it afterwards systemctl stop X rsync data; systemctl start X and go to a coffee is not that uncommon that should always succeed IMO (unless you think that systemctl kill ... should be used in such circumstances?) i think so I really think an ExecRestartPre (or perhaps a more explicit ExecRestartCheck) would be a more sensible name (ExecStopPre implies it would run when explicitly stopping which, as noted above, I think is a bad plan). It wouldn't run when an ExecReload is given explicitly but if that operation falls back to restart, it would. falls back? how? when i say systemctl reload nothing has to trigger a hard restart and even if - in case of a broken config signature.asc Description: OpenPGP digital signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
On Jul 31, 2014 12:57 PM, Reindl Harald h.rei...@thelounge.net wrote: Am 31.07.2014 um 02:16 schrieb Colin Guthrie: Reindl Harald wrote on 30/07/14 13:34: *how* should that both help in calling apachectl -t *before* stop the service and in case of a error-repsonse keep it running? Note, just for clarity, you don't really want to run such a config test when explicitly stopping a service i do want that in case it ends in a state where i can't start it afterwards systemctl stop X rsync data; systemctl start X and go to a coffee is not that uncommon What if the configuration is fine in the beginning, but another admin breaks it while your rsync is running? -- Mantas Mikulėnas graw...@gmail.com // sent from phone ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] Support for pre-restart check
Hi, while looking at how to convert sysvinit scripts to service files in Debian, I noticed that some scripts do an additional sanity check during the restart action. That is, they run an extra command to validate the configuration and only restart the service on success. Systemd doesn't seem to provide such an option so far. Would you think this is something one would like to see? If yes, what about the following idea: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error. Ansgar ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Am 30.07.2014 12:22, schrieb Ansgar Burchardt: while looking at how to convert sysvinit scripts to service files in Debian, I noticed that some scripts do an additional sanity check during the restart action. That is, they run an extra command to validate the configuration and only restart the service on success. Systemd doesn't seem to provide such an option so far. Would you think this is something one would like to see? If yes, what about the following idea: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error as sysadmin i say: oh yes, that would be cool! the first canmdidate would be Apache httpd ExecRestartPre=/usr/sbin/apachectl -t that would cat cases where you hard restart httpd after library updates and some other guy made a typo in a config or is still woking on it apachectl graceful in such cases refuses the restart signature.asc Description: OpenPGP digital signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
On 07/30/2014 10:22 AM, Ansgar Burchardt wrote: Hi, while looking at how to convert sysvinit scripts to service files in Debian, I noticed that some scripts do an additional sanity check during the restart action. That is, they run an extra command to validate the configuration and only restart the service on success. Systemd doesn't seem to provide such an option so far. Would you think this is something one would like to see? If yes, what about the following idea: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error. Re-sending to list due to simple clicking reply not reply-list mistake. This has been discussed before and check the archive for that discussion but the bottom line is that this is not needed we already have ExecStartPre=, ExecStartPost=, ExecStop=, ExecStopPost=, or ExecReload= which cover those usecases JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Hi, On 07/30/2014 13:26, Jóhann B. Guðmundsson wrote: On 07/30/2014 10:22 AM, Ansgar Burchardt wrote: while looking at how to convert sysvinit scripts to service files in Debian, I noticed that some scripts do an additional sanity check during the restart action. That is, they run an extra command to validate the configuration and only restart the service on success. Systemd doesn't seem to provide such an option so far. Would you think this is something one would like to see? If yes, what about the following idea: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error. This has been discussed before and check the archive for that discussion but the bottom line is that this is not needed we already have ExecStartPre=, ExecStartPost=, ExecStop=, ExecStopPost=, or ExecReload= which cover those usecases I searched for such discussion, but did not find anything relevant. Do you have a link? And how would you use the existing Exec* options to cover this usecase? ExecStart* certainly doesn't help, ExecReload only works for reload and not for restart. ExecStop is to actually stop the service (and should not fail due to invalid configuration); ExecStopPost is too late. Ansgar ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
On Wed, Jul 30, 2014 at 11:26:38AM +, Jóhann B. Guðmundsson wrote: On 07/30/2014 10:22 AM, Ansgar Burchardt wrote: Hi, while looking at how to convert sysvinit scripts to service files in Debian, I noticed that some scripts do an additional sanity check during the restart action. That is, they run an extra command to validate the configuration and only restart the service on success. Systemd doesn't seem to provide such an option so far. Would you think this is something one would like to see? If yes, what about the following idea: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error. Re-sending to list due to simple clicking reply not reply-list mistake. This has been discussed before and check the archive for that discussion but the bottom line is that this is not needed we already have ExecStartPre=, ExecStartPost=, ExecStop=, ExecStopPost=, or ExecReload= which cover those usecases If that is the case, we should really delete TODO item: * maybe introduce ExecRestartPre Michal JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
On Wed, 30.07.14 12:22, Ansgar Burchardt (ans...@debian.org) wrote: Hi, while looking at how to convert sysvinit scripts to service files in Debian, I noticed that some scripts do an additional sanity check during the restart action. That is, they run an extra command to validate the configuration and only restart the service on success. Systemd doesn't seem to provide such an option so far. Would you think this is something one would like to see? If yes, what about the following idea: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error. This has been a TODO item since a long time. The usecase seems valid. So far nobody found the time to implement this though. Happy to take patches... Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Am 30.07.2014 13:42, schrieb Ansgar Burchardt: On 07/30/2014 13:26, Jóhann B. Guðmundsson wrote: On 07/30/2014 10:22 AM, Ansgar Burchardt wrote: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error. This has been discussed before and check the archive for that discussion but the bottom line is that this is not needed we already have ExecStartPre=, ExecStartPost=, ExecStop=, ExecStopPost=, or ExecReload= which cover those usecases I searched for such discussion, but did not find anything relevant. Do you have a link? And how would you use the existing Exec* options to cover this usecase? ExecStart* certainly doesn't help, ExecReload only works for reload and not for restart. ExecStop is to actually stop the service (and should not fail due to invalid configuration); ExecStopPost is too late they don't ExecStopPost is too late, the service is stopped ExecReload is a different game ExecStartPre don't help to prevent the stop hardly any of the existing options is able to *prevent stop* and ignore the systemctl restart - that would be the semnatic of a non existing ExecStopPre Pre != Post signature.asc Description: OpenPGP digital signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
On 07/30/2014 12:09 PM, Lennart Poettering wrote: On Wed, 30.07.14 12:22, Ansgar Burchardt (ans...@debian.org) wrote: Hi, while looking at how to convert sysvinit scripts to service files in Debian, I noticed that some scripts do an additional sanity check during the restart action. That is, they run an extra command to validate the configuration and only restart the service on success. Systemd doesn't seem to provide such an option so far. Would you think this is something one would like to see? If yes, what about the following idea: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error. This has been a TODO item since a long time. The usecase seems valid. We discussed this either here on the mailinglist, in a bug report in bz.rh or in one of the hackfest and it's on that TODO list is there because in the beginning I thought this was required but after we discussed this the behaviour and after going through the more or less all of the legacy sysv initscripts in Fedora simply using ExecStartPre and ExecStop covered this but by all means introduce this if you no longer think that is the case. JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
On 07/30/2014 12:02 PM, Reindl Harald wrote: they don't Perhaps not in your world which seems to differ from many but in the world that the guy that went through and migrated around 800 legacy sysv initscript you want the exact same check run before the service is started and we already cover that with ExecStartPre= And of those 800 it was exception not a rule if those legacy sysv initscript simply did not call stop/start on restart... Ansgar Burchardt will need to post the initscript he's migrating so we can see if it actually provides an valid usecase to implement this I would be very surprised if it actually did... JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Am 30.07.2014 14:19, schrieb Jóhann B. Guðmundsson: On 07/30/2014 12:09 PM, Lennart Poettering wrote: On Wed, 30.07.14 12:22, Ansgar Burchardt (ans...@debian.org) wrote: while looking at how to convert sysvinit scripts to service files in Debian, I noticed that some scripts do an additional sanity check during the restart action. That is, they run an extra command to validate the configuration and only restart the service on success. Systemd doesn't seem to provide such an option so far. Would you think this is something one would like to see? If yes, what about the following idea: Add an ExecRestartPre option in the [Service] section. These commands are executed when a restart is requested, before the service is stopped. If they fail, the restart is aborted with an error. This has been a TODO item since a long time. The usecase seems valid. We discussed this either here on the mailinglist, in a bug report in bz.rh or in one of the hackfest and it's on that TODO list is there because in the beginning I thought this was required but after we discussed this the behaviour and after going through the more or less all of the legacy sysv initscripts in Fedora simply using ExecStartPre and ExecStop covered this but by all means introduce this if you no longer think that is the case *how* should that both help in calling apachectl -t *before* stop the service and in case of a error-repsonse keep it running? ExecStartPre can only prevent a not or no longer running service to start again, ExecStopPost comes after it is stopped and a ExecStopPre don't exist ExecStopPre would be better suited as the pre-restart check because it would achieve the goal and also prevent stop a service until it's configuration is fixed - that catchs cases where you stop something for whatever reason and expect it would be started at the next boot signature.asc Description: OpenPGP digital signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Am 30.07.2014 14:35, schrieb Jóhann B. Guðmundsson: On 07/30/2014 12:02 PM, Reindl Harald wrote: they don't Perhaps not in your world which seems to differ from many don't jump on that personal level if you would have *read* really what you respond to and not stop at the first two words you would realize the difference without personal attacks - it's not a matter of worlds, it's a *technical fact* but in the world that the guy that went through and migrated around 800 legacy sysv initscript you want the exact same check run before the service is started and we already cover that with ExecStartPre= nobody takes ExecStartPre away from you by add ExecStopPre BTW: what do you gain by that checkj in ExecStartPre? ExecStart would fail anyways, so the service fails with or without the topic is about something like ExecStopPre, what you can achieve with it and not about which hero migrated how much sysv initscripts Ansgar Burchardt will need to post the initscript he's migrating so we can see if it actually provides an valid usecase to implement this I would be very surprised if it actually did... step beside your migration consideration and come back to a generic level by only consider migrations you could remove 80% of all options in systemd.exec that below could be httpd and that's useful for a lot of other services by just have the option to call a helper saying you don't stop me with the current environment because of XYZ you won't be able to start me again in case of httpd all what you need exists for other services it could be implemented if there is a call frankly that could be even useful outside the distribution world for sanity checks implemented by the local administrator Type=simple ExecStartPre=/usr/sbin/apachectl -t ExecStart=/usr/sbin/httpd $OPTIONS -D FOREGROUND ExecStopPre=/usr/sbin/apachectl -t ExecReload=/usr/sbin/httpd $OPTIONS -k graceful signature.asc Description: OpenPGP digital signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
On 07/30/2014 12:34 PM, Reindl Harald wrote: *how* should that both help in calling apachectl -t*before* stop the service and in case of a error-repsonse keep it running? ExecStartPre= takes care of the startup check as in the usecase when the unit is not running and you initially configured the Apache daemon Adding ExecStop= before actual ExecStop= line to stop the daemon takes care of preventing you from restarting you if you made configuration changes while the daemon/services was running should not continue with the stop process if the ExecStop command fails. Anyway beside that point daemon,services that actual come with configuration file syntax checkers like apache does ( maybe in what 20 or so range ) , are few and far between let alone those configuration syntax checker that actually exist out there fail properly if they do... JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Am 30.07.2014 15:04, schrieb Jóhann B. Guðmundsson: On 07/30/2014 12:34 PM, Reindl Harald wrote: *how* should that both help in calling apachectl -t *before* stop the service and in case of a error-repsonse keep it running? ExecStartPre= takes care of the startup check as in the usecase when the unit is not running and you initially configured the Apache daemon first: please don't ignore the last paragraphs! takes care about what? the service would fail with or without that Adding ExecStop= before actual ExecStop= line to stop the daemon takes care of preventing you from restarting you if you made configuration changes while the daemon/services was running should not continue with the stop process if the ExecStop command fails. but you don't need ExecStop for most services systemd sends SIGTERM and so ExecStopPre would also affect services without ExecStop lines which are most of mine why? because they don't need CAP_KILL! that's from production, no ExecStop used [Service] Type=simple EnvironmentFile=-/etc/sysconfig/httpd Environment=PATH=/usr/bin:/usr/sbin ExecStart=/usr/sbin/httpd $OPTIONS -D FOREGROUND ExecReload=/usr/sbin/httpd $OPTIONS -k graceful Restart=always RestartSec=1 PrivateTmp=yes NoNewPrivileges=yes CapabilityBoundingSet=CAP_DAC_OVERRIDE CAP_IPC_LOCK CAP_NET_BIND_SERVICE CAP_SETGID CAP_SETUID ReadOnlyDirectories=/etc ReadOnlyDirectories=/usr ReadOnlyDirectories=/var/lib InaccessibleDirectories=/home InaccessibleDirectories=/media InaccessibleDirectories=/root InaccessibleDirectories=/proc InaccessibleDirectories=/sys InaccessibleDirectories=/run/console InaccessibleDirectories=/run/dbus InaccessibleDirectories=/run/lock InaccessibleDirectories=/run/mount InaccessibleDirectories=/run/systemd/generator InaccessibleDirectories=/run/systemd/system InaccessibleDirectories=/run/systemd/users InaccessibleDirectories=/run/udev InaccessibleDirectories=/run/user InaccessibleDirectories=/var/lib/dbus InaccessibleDirectories=/var/lib/rpm InaccessibleDirectories=/var/lib/systemd InaccessibleDirectories=/var/lib/yum InaccessibleDirectories=/var/spool Anyway beside that point daemon,services that actual come with configuration file syntax checkers like apache does (maybe in what 20 or so range), are few and far between let alone those configuration syntax checker that actually exist out there fail properly if they do... step away from syntax checkers shipped with daemons, they are only one usecase (and maybe there would be some more in a few years with reliebale ways to use them with systemd) ExecStopPost could be any script written by the local administrator which says you don't stop that service in case service A and B are runnining which *hard fail* if you take them away the database and so i ordered start/shutdown of the machine correctly but without hard Requires= and their drawbacks in units files * drawbacks of Requires=: stop one service required by others stops them too, but start it don't start them at the same moment which is good because as example mysqld can run without dbmail-imapd but not the other way round so one could optimize the environment that restart/stop mysqld only is possible if dbamil-imapd is not running and systemctl restart dbmail-imapd.service mysqld.service does the correct order by After=/Before= in the services depending on mysqld signature.asc Description: OpenPGP digital signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
Reindl Harald wrote on 30/07/14 13:34: *how* should that both help in calling apachectl -t *before* stop the service and in case of a error-repsonse keep it running? Note, just for clarity, you don't really want to run such a config test when explicitly stopping a service - that should always succeed IMO (unless you think that systemctl kill ... should be used in such circumstances?) ExecStopPre would be better suited as the pre-restart check because it would achieve the goal and also prevent stop a service until it's configuration is fixed - that catchs cases where you stop something for whatever reason and expect it would be started at the next boo I really think an ExecRestartPre (or perhaps a more explicit ExecRestartCheck) would be a more sensible name (ExecStopPre implies it would run when explicitly stopping which, as noted above, I think is a bad plan). It wouldn't run when an ExecReload is given explicitly but if that operation falls back to restart, it would. I think the use case is pretty clear tho'. Config (or general machine state) has transitioned from working to broken in the time since the service was started and while it's really not a nice situation to find yourself in (relying on a running service not crashng!), this at least helps avoid nasty consequences for the most part while you work to fix things. Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited http://www.tribalogic.net/ Open Source: Mageia Contributor http://www.mageia.org/ PulseAudio Hacker http://www.pulseaudio.org/ Trac Hacker http://trac.edgewall.org/ ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Support for pre-restart check
On 07/31/2014 12:16 AM, Colin Guthrie wrote: I think the use case is pretty clear tho'. Config (or general machine state) has transitioned from working to broken in the time since the service was started and while it's really not a nice situation to find yourself in (relying on a running service not crashng!), this at least helps avoid nasty consequences for the most part while you work to fix things. The use case administrator want, is fixing their own lazyness and incompetence not having to run the configuration syntax checker by hand after they made changes to the configuration for one of those handful of daemon/service that actually come with those. But let's continue on this path once that is implemented they want to be notified one way or another why the service failed to be restarted as in the actual failed line of the configuration mistake they made so they can go and fix it ( and apachctl -t purpose is... ) but that cannot be implemented in the status output because. remember they where to lazy to run the configuration syntax checker by hand after the change they made so they are to lazy to run systemctl status foo so you do realize the underlying problem for this cannot be solved right? People tried in the past doing so by writing massive initscript that never worked... Now that broken machine state is not limited to configuration changes since it could also happen due to an bad update or incompatable update ( configuration file syntax changes between releases, apache 2.2 vs 2.4 for example ) so the only way you can try to solve this is by introducing a fake restart of the service which cannot be manually defined what is but has to be built in with the know of only turning it on or off for type units which covers *something* has changed can the service be restarted *safely* afterwards, if it does restart the service. Bottom line if the intent is for systemd to solve the use case you stated the solution for this need to be a permanent fix that covers all service/daemons not yet another line that leads to administrators define another command to take care of that... JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
