logger.PutMessage, added in #28762 (v17.04.0-ce), clears msg.Source. So journald
and syslog were treating stderr messages as if they were stdout.
Signed-off-by: David Glasser <glasser@davidglasser.net>
When closing the log-file, and the file is already
closed, there's no need to log an error.
This patch adds a `closed` boolean to check if the
file was closed, and if so, skip closing the file.
This prevents errors like this being logged:
level=error msg="Error closing logger: invalid argument"
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Logging plugins use the same HTTP interface as other plugins for basic
command operations meanwhile actual logging operations are handled (on
Unix) via a fifo.
The plugin interface looks like so:
```go
type loggingPlugin interface {
StartLogging(fifoPath string, loggingContext Context) error
StopLogging(fifoPath)
```
This means a plugin must implement `LoggingDriver.StartLogging` and
`LoggingDriver.StopLogging` endpoints and be able to consume the passed
in fifo.
Logs are sent via stream encoder to the fifo encoded with protobuf.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Refactor container logs system to make communicating log messages
internally much simpler. Move responsibility for marshalling log
messages into the REST server. Support TTY logs. Pave the way for fixing
the ambiguous bytestream format. Pave the way for fixing details.
Signed-off-by: Drew Erny <drew.erny@docker.com>
Make sure that the cursor value returned by followJournal() is the last
of the values returned by its goroutine's calls to drainJournal() by
waiting for it, rather than returning a value that may be superceded by
another if we're singalling the goroutine that it should exit by closing
a pipe.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
This loop is not ever going to return since it's never actually setting
the `err` var except on the first iteration.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
RFC 5424 (https://tools.ietf.org/html/rfc5424#section-6.2) requires that
STRUCTURED-DATA be present, either as NILVALUE (-) or as one or more
SD-ELEMENT items. Because Docker doesn't ever create any SD-ELEMENT items,
the format should output the NILVALUE instead. This resolves parsing issues
in various RFC 5424-compliant syslog servers.
Signed-off-by: Mark Parker <godefroi@gmail.com>
This reduces allocs and bytes used per log entry significantly as well
as some improvement to time per log operation.
Each log driver, however, must put messages back in the pool once they
are finished with the message.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This allows the user to set a logging mode to "blocking" (default), or
"non-blocking", which uses the ring buffer as a proxy to the real log
driver.
This allows a container to never be blocked on stdio at the cost of
dropping log messages.
Introduces 2 new log-opts that works for all drivers, `log-mode` and
`log-size`. `log-mode` takes a value of "blocking", or "non-blocking"
I chose not to implement this as a bool since it is difficult to
determine if the mode was set to false vs just not set... especially
difficult when merging the default daemon config with the container config.
`log-size` takes a size string, e.g. `2MB`, which sets the max size
of the ring buffer. When the max size is reached, it will start
dropping log messages.
```
BenchmarkRingLoggerThroughputNoReceiver-8 2000000000 36.2 ns/op 856.35 MB/s 0 B/op 0 allocs/op
BenchmarkRingLoggerThroughputWithReceiverDelay0-8 300000000 156 ns/op 198.48 MB/s 32 B/op 0 allocs/op
BenchmarkRingLoggerThroughputConsumeDelay1-8 2000000000 36.1 ns/op 857.80 MB/s 0 B/op 0 allocs/op
BenchmarkRingLoggerThroughputConsumeDelay10-8 1000000000 36.2 ns/op 856.53 MB/s 0 B/op 0 allocs/op
BenchmarkRingLoggerThroughputConsumeDelay50-8 2000000000 34.7 ns/op 894.65 MB/s 0 B/op 0 allocs/op
BenchmarkRingLoggerThroughputConsumeDelay100-8 2000000000 35.1 ns/op 883.91 MB/s 0 B/op 0 allocs/op
BenchmarkRingLoggerThroughputConsumeDelay300-8 1000000000 35.9 ns/op 863.90 MB/s 0 B/op 0 allocs/op
BenchmarkRingLoggerThroughputConsumeDelay500-8 2000000000 35.8 ns/op 866.88 MB/s 0 B/op 0 allocs/op
```
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This fix tries to address the issue raised in 29344 where it was
not possible to create log group for awslogs (CloudWatch) on-demand.
Log group has to be created explicitly before container is running.
This behavior is inconsistent with AWS logs agent where log groups
are always created as needed.
There were several concerns previously (See comments in 19617 and 29344):
1. There is a limit of 500 log groups/account/region so resource might
be exhausted if there is any typo or incorrect region.
2. Logs are generated for every container so CreateLogGroup (or equally,
DescribeLogGroups) might be called every time, which is redundant and
potentially surprising.
3. CreateLogStream and CreateLogGroup have different IAM policies.
This fix addresses the issue by add `--log-opt awslogs-create-group`
which by default is `false`. It requires user to explicitly request
that log groups be created as needed.
Related unit test has been updated. And tests have also been done
manually in AWS.
This fix fixes 29334.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
In the journald log driver, attempt to drain the journal 1 more time
after being told to stop following the log. Due to a possible race
condition, sometimes data is written to the journal at almost the same
time the log watch is closed, and depending on the order of operations,
sometimes you miss the last journal entry.
Signed-off-by: Andy Goldstein <agoldste@redhat.com>
This commit addresses 2 issues:
1. in `tailfile()` if somehow the `logWatcher.Msg` were to become full and the watcher closed before space was made into it, we were getting stuck there forever since we were not checking for the watcher getting closed
2. when servicing `docker logs`, if the command was cancelled we were not closing the watcher (and hence notifying it to stop copying data)
Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>
Fix#29344
If HOME is not set, the gcplogs logging driver will call os/user.Current() via oauth2/google.
However, in static binary, os/user.Current() leads to segfault due to a glibc issue that won't be fixed
in a short term. (golang/go#13470, https://sourceware.org/bugzilla/show_bug.cgi?id=19341)
So we forcibly set HOME so as to avoid call to os/user/Current().
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
The `docker logs` command performed a
client-side check if the container's
logging driver was supported.
Now that we allow the client to connect
to both "older" and "newer" daemon versions,
this check is best done daemon-side.
This patch remove the check on the client
side, and leaves validation to the daemon,
which should be the source of truth.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
We clean up the journald logger with these four changes.
1. Make field array static
2. Make function name more appropriate
3. Initialize the file descriptors only once
4. Avoid copying the journald cursor
Point 4 is the most significant change: instead of treating the journald
cursor like a Go string we use it as a raw C.char pointer. That way we
avoid the copying by the C.CString and C.GoString functions.
Signed-off-by: Silvan Jegen <s.jegen@gmail.com>
Fixes#27779
Currently `followLogs` can get into a deadlock if we receive an inotify
IN_MODIFY event while we are trying to close the `fileWatcher`. This is
due to the fact that closing the `fileWatcher` happens in the same block
as consumes events from the `fileWatcher`. We are trying to run
`fileWatcher.Close`, which is waiting for an IN_IGNORE event to come in
over inotify to confirm the watch was been removed. But, because an
IN_MODIFY event has appeared after `Close` was entered but before the
IN_IGNORE, the broadcast never comes. The IN_MODIFY cannot be consumed
as the events channel is unbuffered and the only `select` that reads
from it is busy waiting for the IN_IGNORE event.
In order to try and fix this race condition I've moved the removal of
the `fileWatcher` out to a separate go block that waits for a signal to
close, removes the watcher and then signals to the previous selects on
the close signal.
This has introduced a `fileWatcher.Remove` in the final case, but if we
try and remove a watcher that does not exist it will just return an
error saying so. We are not doing any checking on the return of `Remove`
so this shouldn't cause any side-effects.
Signed-off-by: Tom Booth <tombooth@gmail.com>
`golint` had the following issue when linting this file:
```
daemon/logger/jsonfilelog/read.go:116:10: should omit type io.Reader
from declaration of var rdr; it will be inferred from the right-hand
side
```
In order to keep it happy changing it to an indirect assignment will
still maintain the same functionality.
Signed-off-by: Tom Booth <tombooth@gmail.com>
New driver options:
- `splunk-gzip` - gzip compress all requests to Splunk HEC
(enabled by default)
- `splunk-gzip-level` - change compression level.
Messages are sent in batches by 1000, with frequency of 5 seconds.
Maximum buffer is 10,000 events. If HEC will not be available, Splunk
Logging Driver will keep retrying while it can hold messages in buffer.
Added unit tests for driver.
Signed-off-by: Denis Gladkikh <denis@gladkikh.email>
`--log-opt splunk-format=inline|json|raw` allows to change how logging
driver sends data to Splunk, where
`inline` - default value, format used before, message is injected as a
line in JSON payload
`json` - driver will try to parse each line as a JSON object and embed it
inside of the JSON payload
`raw` - driver will send Raw payload instead of JSON, tag and attributes
will be prefixed before the message
`--log-opt splunk-verify-connection=true|false` - allows to skip
verification for Splunk Url
Signed-off-by: Denis Gladkikh <denis@gladkikh.email>
Fixes a race where the log reader would get events for both an actual
rotation as we from fsnotify (`fsnotify.Rename`).
This issue becomes extremely apparent when rotations are fast, for
example:
```
$ docker run -d --name test --log-opt max-size=1 --log-opt max-file=2
busybox sh -c 'while true; do echo hello; usleep 100000; done'
```
With this change the log reader for jsonlogs can handle rotations that
happen as above.
Instead of listening for both fs events AND rotation events
simultaneously, potentially meaning we see 2 rotations for only a single
rotation due to channel buffering, only listen for fs events (like
`Rename`) and then wait to be notified about rotation by the logger.
This makes sure that we don't see 2 rotations for 1, and that we don't
start trying to read until the logger is actually ready for us to.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This fix tries to address the issue raised in #23528 where
docker labels caused journald log error because journald
has special requirements on field names.
This fix addresses this issue by sanitize the labels per
requirements of journald.
Additional unit tests have been added to cover the changes.
This fix fixes#23528.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
If "docker logs" was used on an offline container, the logger is leaked, leaving it up to the finalizer to close the file handle, which could block removal of the container. Further, the json file logger could leak an open handle if the logs are read without follow due to an early return without a close. This change addresses both cases.
Signed-off-by: Stefan J. Wernli <swernli@microsoft.com>
This change updates how we handle long lines of output from the
container. The previous logic used a bufio reader to read entire lines
of output from the container through an intermediate BytesPipe, and that
allowed the container to cause dockerd to consume an unconstrained
amount of memory as it attempted to collect a whole line of output, by
outputting data without newlines.
To avoid that, we replace the bufio reader with our own buffering scheme
that handles log lines up to 16k in length, breaking up anything longer
than that into multiple chunks. If we can dispense with noting this
detail properly at the end of output, we can switch from using
ReadBytes() to using ReadLine() instead. We add a field ("Partial") to
the log message structure to flag when we pass data to the log driver
that did not end with a newline.
The Line member of Message structures that we pass to log drivers is now
a slice into data which can be overwritten between calls to the log
driver's Log() method, so drivers which batch up Messages before
processing them need to take additional care: we add a function
(logger.CopyMessage()) that can be used to create a deep copy of a
Message structure, and modify the awslogs driver to use it.
We update the jsonfile log driver to append a "\n" to the data that it
logs to disk only when the Partial flag is false (it previously did so
unconditionally), to make its "logs" output correctly reproduce the data
as we received it.
Likewise, we modify the journald log driver to add a data field with
value CONTAINER_PARTIAL_MESSAGE=true to entries when the Partial flag is
true, and update its "logs" reader to refrain from appending a "\n" to
the data that it retrieves if it does not see this field/value pair (it
also previously did this unconditionally).
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
Add a benchmark for measuring how the logger.Copier implementation
handles logged lines of sizes ranging up from 64 bytes to 256KB.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
When told to read additional attributes from logs that we've sent to the
journal, pull out all of the non-trusted, non-user fields that we didn't
hard-code ourselves. More of PR#20726 and PR#21889.
When reading entries in the journald log reader, set the time zone on
timestamps that we read to UTC, so that we send UTC values to the client
instead of values that are local to whatever timezone dockerd happens to
be running in.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
Log drivers are instantiated on a per-container basis, and passed the
container ID (along with other information) when they're initialized.
Drivers that care about that value are caching the value that they're
passed when they're initialized and using it in favor of the value
contained in Message structures that are passed to them, so the field in
Messages is unused, so we remove it.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
This fix tries to fix build errors caused by updating
aws-sdk-go to v1.1.30.
This fix fixes#22961.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
This fix tries to address the issue raised in #22358 where syslog's
message tag always starts with `docker/` and can not be removed
by changing the log tag templates.
The issue is that syslog driver hardcodes `path.Base(os.Args[0])`
as the prefix, which is the binary file name of the daemon (`dockerd`).
This could be an issue for certain situations (e.g., #22358) where
user may prefer not to have a dedicated prefix in syslog messages.
There is no way to override this behavior in the current verison of
the docker.
This fix tries to address this issue without making changes in the
default behavior of the syslog driver. An additional
`{{.DaemonName}}` has been introduced in the syslog tag. This is
assigned as the `docker` when daemon starts. The default log tag
template has also been changed from
`path.Base(os.Args[0]) + "/{{.ID}}"` to `{{.DaemonName}}/{{.ID}}`.
Therefore, there is no behavior changes when log-tag is not provided.
In order to be consistent, the default log tag for fluentd has been
changed from `docker.{{.ID}}` to `{{DaemonName}}.{{.ID}}` as well.
The documentation for log-tag has been updated to reflect this change.
Additional test cases have been added to cover changes in this fix.
This fix fixes#22358.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Since 1.9, driver specific log tag options
`syslog-tag`
`gelf-tag`
`fluentd-tag`
have been deprecated in favor of the generic tag
option which is standard across different logging
drivers.
This fix removed the deprecated driver specific
log tag options of `syslog-tag`, `gelf-tag`,
`fluentd-tag` for 1.12 and updated the docs.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
The jsonlog logger currently allows specifying envs and labels that
should be propagated to the log message, however there has been no way
to read that back.
This adds a new API option to enable inserting these attrs back to the
log reader.
With timestamps, this looks like so:
```
92016-04-08T15:28:09.835913720Z foo=bar,hello=world hello
```
The extra attrs are comma separated before the log message but after
timestamps.
Without timestaps it looks like so:
```
foo=bar,hello=world hello
```
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This fix tries to add an additional syslog-format of `rfc5424micro` which follows
the same as rfc5424 except that it use microsecond resolution for timestamp. The
purpose is to solve the issue raised in #21793 where log events might lose its
ordering if happens on the same second.
The timestamp field in rfc5424 is derived from rfc3339, though the maximium
resolution is limited to "TIME-SECFRAC" which is 6 (microsecond resolution).
The appropriate documentation (`docs/admin/logging/overview.md`) has been updated
to reflect the change in this fix.
This fix adds a unit test to cover the newly introduced format.
This fix fixes#21793.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Following a journal log almost always requires a descriptor to be
allocated. In cases where we're running out of descriptors, this means
we might get stuck while attempting to start following the journal, at a
point where it's too late to report it to the client and clean up
easily. The journal reading context will cache the value once it's
allocated, so here we move the check earlier, so that we can detect a
problem when we can still report it cleanly.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
When we set up to start following a journal, if we get error results
from sd_journal_get_fd() or sd_journal_get_events() that prevent us from
following the journal, report the error instead of just mysteriously
failing.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
This cleans up some of the use of the filepoller which makes reading
significantly more robust and gives fewer changes to fallback to the
polling based watcher.
In a lot of cases, if the file was being rotated while we were adding it
to the watcher, it would return an error that the file doesn't exist and
would fallback.
In some cases this fallback could be triggered multiple times even if we
were already on the fallback/poll-based watcher.
It also fixes an open file leak caused by not closing files properly on
rotate, as well as not closing files that were read via the `tail`
function until after the log reader is completed.
Prior to the above changes, it was relatively simple to cause the log
reader to error out by having quick rotations, for example:
```
$ docker run --name test --log-opt max-size=10b --log-opt max-files=10
-d busybox sh -c 'while true; do usleep 500000; echo hello; done'
$ docker logs -f test
```
After these changes I can run this forever without error.
Another fix removes 2 `os.Stat` calls when rotating files. The stat
calls are not needed since we are just calling `os.Rename` anyway, which
will in turn also just produce the same error that `Stat` would.
These `Stat` calls were also quite expensive.
Removing these stat calls also seemed to resolve an issue causing slow
memory growth on the daemon.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
When following a journal-based log, it was possible for the worker
goroutine, which reads the journal using the journal context and sends
entry data down the message channel, to be scheduled after the function
which started it had returned. This could create problems, since the
invoking function was closing the journal context object and message
channel before it returned, which could trigger use-after-free segfaults
and write-to-closed-channel panics in the worker goroutine.
Make the cleanup in the invoking function conditional so that it's only
done when we're not following the logs, and if we are, that it's left to
the worker goroutine to close them.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
The journald log reader keeps a map of following readers so that it can
close them properly when the journald reader object itself is closed,
but it was possible for its worker goroutine to be scheduled so that the
worker attempted to remove a reader from the map before the reader had
been added to the map. This patch adds the item to the map before
starting the goroutine which is expected to eventually remove it.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
The GCP logging driver is calling out to GCP cloud service on package
init.
This is regardless if you are using GCP logging or not.
This change makes this happen on the first invocation of a new GCP
logging driver instance instead.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
this allows user to choose the compression type (i.e. gzip/zlib/none) using
--log-opt=gelf-compression-type=none or the compression level (-1..9) using
--log-opt=gelf-compression-level=0 for gelf driver.
Signed-off-by: Daniel Dao <dqminh@cloudflare.com>
This change centralizes the template manipulation in a single package
and adds basic string functions to their execution.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Previously docker used obsolete rfc3164 syslog format for syslog. rfc3164 explicitly
uses semicolon as a separator between 'TAG' and 'Content' section of the log message.
Docker uses semicolon as a separator between image name and version tag.
When {{.ImageName}} was used as a tag expression and contained ":" syslog parser mistreated
"tag" part of the image name as syslog message body, which resulted in incorrect "syslogtag" been reported by syslog
daemon.
Use of rfc5424 log format partually fixes the issue as it does not use semicolon as a separator.
However using default rfc5424 syslog format itroduces backward incompatability because rsyslog template keyword %syslogtag%
is parsed differently. In rfc3164 it uses the "TAG" part reported before the "pid" part. In rfc5424 it uses "appname" part reported
before the pid part, while tag part is introduced by %msgid% part.
For more information on rsyslog configuration properties see: http://www.rsyslog.com/doc/master/configuration/properties.html
Added two options to specify logging in either rfc5424, rfc3164 format or unix format omitting hostname in order to keep backwards compatability with
previous versions.
Signed-off-by: Solganik Alexander <solganik@gmail.com>
When checking if we have the development files for libsystemd's journal
APIs, check for either 'libsystemd >= 209' and 'libsystemd-journal'. If
we find 'libsystemd', define the 'journald' tag, which defaults to using
the 'libsystemd.pc' file. If we find the older 'libsystemd-journal',
define both the 'journald' and 'journald_compat' tags, which causes the
'libsystemd-journal.pc' file to be consulted instead.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
inotify event is trigged immediately there's data written to disk.
But at the time that the inotify event is received, the json line might
not fully saved to disk. If the json decoder tries to decode in such
case, an io.UnexpectedEOF will be trigged.
We used to retry for several times to mitigate the io.UnexpectedEOF error.
But there are still flaky tests caused by the partial log entries.
The daemon knows exactly when there are new log entries emitted. We can
use the pubsub package to notify all the log readers instead of inotify.
Signed-off-by: Shijiang Wei <mountkin@gmail.com>
try to fix broken test. will squash once tests pass
Signed-off-by: Shijiang Wei <mountkin@gmail.com>
Signed-off-by: Jussi Nummelin <jussi.nummelin@gmail.com>
Changed buffer size to 1M and removed unnecessary fmt call
Signed-off-by: Jussi Nummelin <jussi.nummelin@gmail.com>
Updated docs for the new fluentd opts
Signed-off-by: Jussi Nummelin <jussi.nummelin@gmail.com>
this prevents the copier from sending messages in the buffer to the closed
driver. If the copied took longer than the timeout to drain the buffer, this
aborts the copier read loop and return back so we can cleanup resources
properly.
Signed-off-by: Daniel Dao <dqminh@cloudflare.com>
- Move time json marshaling to the jsonlog package: this is a docker
internal hack that we should not promote as a library.
- Move Timestamp encoding/decoding functions to the API types: This is
only used there. It could be a standalone library but I don't this
it's worth having a separated repo for this. It could introduce more
complexity than it solves.
Signed-off-by: David Calavera <david.calavera@gmail.com>
Add support of `tag`, `env` and `labels` for Splunk logging driver.
Removed from message `containerId` as it is the same as `tag`.
Signed-off-by: Denis Gladkikh <denis@gladkikh.email>
The json decoder starts to decode immediately an inotify event is
received.
But at the time the inotify event is trigged, the json log
entry might haven't been fully written to the disk.
In this case the decoder will return an "io.UnexpectedEOF" error, but
there is still data remaining in the decoder's buffer. And the data
should be passed to the decoder when the next inotify event is
triggered.
Signed-off-by: Shijiang Wei <mountkin@gmail.com>
this allows jsonfile logger to collect extra metadata from containers with
`--log-opt labels=label1,label2 --log-opt env=env1,env2`.
Extra attributes are saved into `attrs` attributes for each log data.
Signed-off-by: Daniel Dao <dqminh@cloudflare.com>
this allows journald logger to collect extra metadata from containers with
`--log-opt labels=label1,label2 --log-opt env=env1,env2`
Signed-off-by: Daniel Dao <dqminh@cloudflare.com>
this allows fluentd logger to collect extra metadata from containers with
`--log-opt labels=label1,label2 --log-opt env=env1,env2`
Signed-off-by: Daniel Dao <dqminh@cloudflare.com>
this allows gelf logger to collect extra metadata from containers with
`--log-opt labels=label1,label2 --log-opt env=env1,env2`
Additional log field will be prefixed with `_` as per gelf protocol
https://www.graylog.org/resources/gelf/
Signed-off-by: Daniel Dao <dqminh@cloudflare.com>
If an invalid logger address is provided on daemon start it will
silently fail. As syslog driver is doing, this check should be done on
daemon start and prevent it from starting even in other drivers.
This patch also adds integration tests for this behavior.
Signed-off-by: Antonio Murdaca <runcom@linux.com>
@noxiouz points out that we don't need to check for a nil result from
C.CString(), since an out-of-memory condition causes a runtime panic
instead.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
If a logdriver doesn't register a callback function to validate log
options, it won't be usable. Fix the journald driver by adding a dummy
validator.
Teach the client and the daemon's "logs" logic that the server can also
supply "logs" data via the "journald" driver. Update documentation and
tests that depend on error messages.
Add support for reading log data from the systemd journal to the
journald log driver. The internal logic uses a goroutine to scan the
journal for matching entries after any specified cutoff time, formats
the messages from those entries as JSONLog messages, and stuffs the
results down a pipe whose reading end we hand back to the caller.
If we are missing any of the 'linux', 'cgo', or 'journald' build tags,
however, we don't implement a reader, so the 'logs' endpoint will still
return an error.
Make the necessary changes to the build setup to ensure that support for
reading container logs from the systemd journal is built.
Rename the Jmap member of the journald logdriver's struct to "vars" to
make it non-public, and to make it easier to tell that it's just there
to hold additional variable values that we want journald to record along
with log data that we're sending to it.
In the client, don't assume that we know which logdrivers the server
implements, and remove the check that looks at the server. It's
redundant because the server already knows, and the check also makes
using older clients with newer servers (which may have new logdrivers in
them) unnecessarily hard.
When we try to "logs" and have to report that the container's logdriver
doesn't support reading, send the error message through the
might-be-a-multiplexer so that clients which are expecting multiplexed
data will be able to properly display the error, instead of tripping
over the data and printing a less helpful "Unrecognized input header"
error.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
After tailing a file, if the number of lines requested is > the number
of lines in the file, this would cause a json unmarshalling error to
occur when we later try to go follow the file.
So brute force set it to the end if any tailing occurred.
There is potential that there could be some missing log messages if logs
are being written very quickly, however I was not able to make this
happen even with `while true; do echo hello; done`, so this is probably
acceptable.
While testing this I also found a panic in LogWatcher.Close can be
called twice due to a race. Fix channel close to only close when there
has been no signal to the channel.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
