Docker daemon has a 16K buffer for log messages. If a message length
exceeds 16K, it should be split by the logger and merged at the
endpoint.
This change adds `PartialLogMetaData` struct for enhanced partial support
- LastPartial (bool) : indicates if this is the last of all partials.
- ID (string) : unique 32 bit ID. ID is same across all partials.
- Ordinal (int starts at 1) : indicates the position of msg in the series of partials.
Also, the timestamps across partials in the same.
Signed-off-by: Anusha Ragunathan <anusha.ragunathan@docker.com>
Before this change, volume management was relying on the fact that
everything the plugin mounts is visible on the host within the plugin's
rootfs. In practice this caused some issues with mount leaks, so we
changed the behavior such that mounts are not visible on the plugin's
rootfs, but available outside of it, which breaks volume management.
To fix the issue, allow the plugin to scope the path correctly rather
than assuming that everything is visible in `p.Rootfs`.
In practice this is just scoping the `PropagatedMount` paths to the
correct host path.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
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>
