This commit ensures that when a plugin instance is closed the goroutines
responsible for streaming stdout and stderr of the called binary will
also exit, preventing a goroutines leak.
Before this commit these goroutines could stay blocked forever if
Close() was called while the binary still had some pending output.
I found this bug after debugging a real world goroutine leak, the
goroutines dump would show thousands of goroutines at:
```
github.com/tsuru/tsuru/vendor/github.com/docker/machine/libmachine/drivers/plugin/localbinary.stream(0xc023013d80, 0xc0000aad20)
/home/travis/gopath/src/github.com/tsuru/tsuru/vendor/github.com/docker/machine/libmachine/drivers/plugin/localbinary/plugin.go:177 +0x7c
created by github.com/tsuru/tsuru/vendor/github.com/docker/machine/libmachine/drivers/plugin/localbinary.(*Plugin).AttachStream
/home/travis/gopath/src/github.com/tsuru/tsuru/vendor/github.com/docker/machine/libmachine/drivers/plugin/localbinary/plugin.go:183 +0x67
```
Signed-off-by: Cezar Sa Espinola <cezarsa@gmail.com>
This replaces the previous method of attempting to clean up servers when
an unexpected exit occurs in the client (e.g. SIGINT or panic) by a
heartbeat protocol. If the server does not hear from the connecting
client within a certain interval of time (500ms in this commit), it will
de-activate itself. This prevents dangling Docker Machine server
processes from accumulating.
Signed-off-by: Nathan LeClaire <nathan.leclaire@gmail.com>
- First RPC steps
- Work on some flaws in RPC model
- Remove unused TLS settings from Engine and Swarm options
- Add code to correctly encode data over the network
- Add client driver for RPC
- Rename server driver file
- Start to make marshal make sense
- Fix silly RPC method args and add client
- Fix some issues with RPC calls, and marshaling
- Simplify plugin main.go
- Move towards 100% plugin in CLI
- Ensure that plugin servers are cleaned up properly
- Make flag parsing for driver flags work properly
Includes some work carried from @dmp42 updating the build process and
tests to use the new method.
Signed-off-by: Nathan LeClaire <nathan.leclaire@gmail.com>
