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>
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)
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>
