Commit graph

9 commits

Author SHA1 Message Date
Lennart Poettering dccca82b1a log: minimize includes in log.h
log.h really should only include the bare minimum of other headers, as
it is really pulled into pretty much everything else and already in
itself one of the most basic pieces of code we have.

Let's hence drop inclusion of:

1. sd-id128.h because it's entirely unneeded in current log.h
2. errno.h, dito.
3. sys/signalfd.h which we can replace by a simple struct forward
   declaration
4. process-util.h which was needed for getpid_cached() which we now hide
   in a funciton log_emergency_level() instead, which nicely abstracts
   the details away.
5. sys/socket.h which was needed for struct iovec, but a simple struct
   forward declaration suffices for that too.

Ultimately this actually makes our source tree larger (since users of
the functionality above must now include it themselves, log.h won't do
that for them), but I think it helps to untangle our web of includes a
tiny bit.

(Background: I'd like to isolate the generic bits of src/basic/ enough
so that we can do a git submodule import into casync for it)
2018-01-11 14:44:31 +01:00
Shawn Landden 4831981d89 tree-wide: adjust fall through comments so that gcc is happy
Distcc removes comments, making the comment silencing
not work.

I know there was a decision against a macro in commit
ec251fe7d5
2017-11-20 13:06:25 -08:00
Zbigniew Jędrzejewski-Szmek 53e1b68390 Add SPDX license identifiers to source files under the LGPL
This follows what the kernel is doing, c.f.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5fd54ace4721fc5ce2bb5aef6318fcf17f421460.
2017-11-19 19:08:15 +01:00
Yu Watanabe 945c2931bb libsystemd: use IN_SET macro 2017-09-28 17:37:59 +09:00
Evgeny Vereshchagin da2d142114 sd-id128: id128_write overwrites target file 2016-12-13 13:03:14 +00:00
Lennart Poettering 4b58153dd2 core: add "invocation ID" concept to service manager
This adds a new invocation ID concept to the service manager. The invocation ID
identifies each runtime cycle of a unit uniquely. A new randomized 128bit ID is
generated each time a unit moves from and inactive to an activating or active
state.

The primary usecase for this concept is to connect the runtime data PID 1
maintains about a service with the offline data the journal stores about it.
Previously we'd use the unit name plus start/stop times, which however is
highly racy since the journal will generally process log data after the service
already ended.

The "invocation ID" kinda matches the "boot ID" concept of the Linux kernel,
except that it applies to an individual unit instead of the whole system.

The invocation ID is passed to the activated processes as environment variable.
It is additionally stored as extended attribute on the cgroup of the unit. The
latter is used by journald to automatically retrieve it for each log logged
message and attach it to the log entry. The environment variable is very easily
accessible, even for unprivileged services. OTOH the extended attribute is only
accessible to privileged processes (this is because cgroupfs only supports the
"trusted." xattr namespace, not "user."). The environment variable may be
altered by services, the extended attribute may not be, hence is the better
choice for the journal.

Note that reading the invocation ID off the extended attribute from journald is
racy, similar to the way reading the unit name for a logging process is.

This patch adds APIs to read the invocation ID to sd-id128:
sd_id128_get_invocation() may be used in a similar fashion to
sd_id128_get_boot().

PID1's own logging is updated to always include the invocation ID when it logs
information about a unit.

A new bus call GetUnitByInvocationID() is added that allows retrieving a bus
path to a unit by its invocation ID. The bus path is built using the invocation
ID, thus providing a path for referring to a unit that is valid only for the
current runtime cycleof it.

Outlook for the future: should the kernel eventually allow passing of cgroup
information along AF_UNIX/SOCK_DGRAM messages via a unique cgroup id, then we
can alter the invocation ID to be generated as hash from that rather than
entirely randomly. This way we can derive the invocation race-freely from the
messages.
2016-10-07 20:14:38 +02:00
Lennart Poettering 65548c58dd sd-id128: be more liberal when reading files with 128bit IDs
Accept both files with and without trailing newlines. Apparently some rkt
releases generated them incorrectly, missing the trailing newlines, and we
shouldn't break that.
2016-07-25 20:53:26 +02:00
Lennart Poettering 15b1248a6b machine-id-setup: port machine_id_commit() to new id128-util.c APIs 2016-07-22 12:59:36 +02:00
Lennart Poettering 910fd145f4 sd-id128: split UUID file read/write code into new id128-util.[ch]
We currently have code to read and write files containing UUIDs at various
places. Unify this in id128-util.[ch], and move some other stuff there too.

The new files are located in src/libsystemd/sd-id128/ (instead of src/shared/),
because they are actually the backend of sd_id128_get_machine() and
sd_id128_get_boot().

In follow-up patches we can use this reduce the code in nspawn and
machine-id-setup by adopted the common implementation.
2016-07-22 12:59:36 +02:00