The refCounter used for sharing temporary decompressed log files and
tracking when the files can be deleted is keyed off the source file's
path. But the path of a log file is not stable: it is renamed on each
rotation. Consequently, when logging is configured with both rotation
and compression, multiple concurrent readers of a container's logs could
read logs out of order, see duplicates or decompress a log file which
has already been decompressed.
Replace refCounter with a new implementation, sharedTempFileConverter,
which is agnostic to the file path, keying off the source file's
identity instead. Additionally, sharedTempFileConverter handles the full
lifecycle of the temporary file, from creation to deletion. This is all
abstracted from the consumer: all the bookkeeping and cleanup is handled
behind the scenes when Close() is called on the returned reader value.
Only one file descriptor is used per temporary file, which is shared by
all readers.
A channel is used for concurrency control so that the lock can be
acquired inside a select statement. While not currently utilized, this
makes it possible to add support for cancellation to
sharedTempFileConverter in the future.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Add an extensive test suite for validating the behavior of any
LogReader. Test the current LogFile-based implementations against it.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The io/ioutil package has been deprecated in Go 1.16. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
daemon/volumes_unix_test.go:228:13: SA4001: &*x will be simplified to x. It will not copy x. (staticcheck)
mp: &(*c.MountPoints["/jambolan"]), // copy the mountpoint, expect no changes
^
daemon/logger/local/local_test.go:214:22: SA4001: &*x will be simplified to x. It will not copy x. (staticcheck)
dst.PLogMetaData = &(*src.PLogMetaData)
^
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Before this change, the log decoder function provided by the log driver
to logfile would not be able to re-use buffers, causing undeeded
allocations and memory bloat for dockerd.
This change introduces an interface that allows the log driver to manage
it's memory usge more effectively.
This only affects json-file and local log drivers.
`json-file` still is not great just because of how the json decoder in the
stdlib works.
`local` is significantly improved.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This driver uses protobuf to store log messages and has better defaults
for log file handling (e.g. compression and file rotation enabled by
default).
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
