On Tue, Dec 31, 2013 at 06:40:47PM +0400, Andrey Borzenkov wrote: > В Вс, 29/12/2013 в 18:57 +0100, Zbigniew Jędrzejewski-Szmek пишет: > > Hi, > > I'd like to reopen this thread. > > > > I have been looking at our bugs [1-10, there are others too] related to > > enabling/disabling of units and following of symlinks. Currently this > > is an unintuitive mess and some changes will have to be made. > > > > I think that the general rules should be: > > (/lib is short for /usr/lib, /usr/local/lib, etc., > > .wants is short for .wants or .requires) > > > > 1. when given a unit, it must be possible to read information about > > this unit without reading all other units > > > > 2. all symlinks in /run and /etc are considered configuration and > > will be removed by systemctl disable > > > > 3. symlinks within the configuration directories must have > > > > (a) the same symlink and target name, or > > > > (b) the symlink can be a instance and the target a template with > > the same stem and type > > > > (c) in /lib, the name can be different, but the type must match, and this > > provides an alias > > > > 4. systemd must follow the same logic as systemctl and must enforce > > the rules. > > > > This means that: > > If I read this correctly, the end effect is that every systemd unit file > must be found under standard systemd directories. Right? It can either be found as /etc/systemd/system/unit.unit or /lib/systemd/system/unit.file, or a symlink from /etc/systemd/system/unit.unit or /lib/systemd/system/unit.file to the unit file must exist.
> > 1. when linking a unit with 'systemctl enable /path/to/file', > > the unit must be linked both into /etc/systemd/system/ and > > /etc/systemd/systemd/whatever.wants/. This is what systemctl enable > > currently does, but we allowed only the second part done > > manually. systemd would be changed to ignore all files in .wants/, > > and it would be changed to ignore symlinks in .wants if the unit > > cannot be loaded by name otherwise. > > > > What is semantic of having symlink in .wants to different unit file that > would normally be found by systemd. I.e. having both /lib/foo.service > and /etc/foo.service will use /etc version; but what if there is symlink > that points into /lib? Currently we ignore the directory in the symlink destination. I'm pretty sure we should continue to do that. > > 2. symlinking to units to provide an alias is allowed only in /lib. > > When systemctl disable is executed, all symlinks in /etc and /run will > > be nuked, but /lib will be left alone. I think this is current behaviour. > > > > 3. .wants directories and .d directories will only be honored for > > the main unit name. The problem that we have currently is that > > if the alias unit is not pulled in by anything, this extra configuration > > is ignored. But even 'systemctl status' loads the unit, and loads > > this extra configuration. systemd would be changed to warn about this > > and ignore those extra dirs. > > > > 4. support for aliases will be provided on a best-effort basis: If > > the alias is done by symlinking in /lib, it is always known. > > If the alias is provided by Alias= configuration directive, it > > is only known if the unit was already loaded. > > > > There's a bug that 'systemctl disable' removes too much stuff for > > instance units. I can't find the report atm, but this is a bug that > > should be fixed too. > > > > Zbyszek > > > > [1] https://bugs.freedesktop.org/show_bug.cgi?id=72611 > > systemctl is-enabled scales poorly with many units (this one) > > [2] https://bugs.freedesktop.org/show_bug.cgi?id=63621 > > systemctl enable doesn't work for Alias names > > [3] https://bugs.freedesktop.org/show_bug.cgi?id=72154 > > "systemctl enable named.service" yields error messages used for legacy > > sysinit scripts > > [4] https://bugzilla.redhat.com/show_bug.cgi?id=1014311 > > RFE: allow systemctl enable work on symlinked units > > [5] https://bugzilla.redhat.com/show_bug.cgi?id=864298 > > systemctl is-enabled reports 'static' incorrectly (it appears) > > [6] https://bugzilla.redhat.com/show_bug.cgi?id=955379 > > systemctl enable fails for user-defined service files in > > /etc/systemd/system > > [7] https://bugs.freedesktop.org/show_bug.cgi?id=65255 > > some units can be started when the file is just copied into .wants/ > > [8] https://bugs.freedesktop.org/show_bug.cgi?id=54560 > > systemd does not follow symlinks that point outside of > > /etc/systemd/system or /usr/lib/systemd/system > > [9] https://bugzilla.redhat.com/show_bug.cgi?id=1002806 > > runlevel command returns "unknown" > > [10] https://bugzilla.redhat.com/show_bug.cgi?id=815835 > > /sbin/runlevel reports "unknown" where it shouldn't > > > > > > > > On Fri, Dec 13, 2013 at 01:03:30PM -0800, [email protected] wrote: > > > From: David Strauss <[email protected]> > > > > > > --- > > > src/shared/install.c | 7 ++++++- > > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > > > diff --git a/src/shared/install.c b/src/shared/install.c > > > index 17e8a75..512e3df 100644 > > > --- a/src/shared/install.c > > > +++ b/src/shared/install.c > > > @@ -419,10 +419,15 @@ static int find_symlinks_fd( > > > r = q; > > > > > > } else if (de->d_type == DT_LNK) { > > > - _cleanup_free_ char *p = NULL, *dest = NULL; > > > + _cleanup_free_ char *p = NULL, *dest = NULL, > > > *no_inst = NULL; > > > bool found_path, found_dest, b = false; > > > int q; > > > > > > + /* Skip symlinks with a different name the > > > target unit */ > > > + no_inst = > > > unit_name_replace_instance(basename(de->d_name), ""); > > > + if (!streq(no_inst, name)) > > > + continue; > > > + > > > /* Acquire symlink name */ > > > p = path_make_absolute(de->d_name, path); > > > if (!p) > > > -- _______________________________________________ systemd-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/systemd-devel
