This allows the caller to receive multiple times without blocking after
the first call.
This can be useful in cases like this:
```go
ch, _ := task.Wait(ctx)
defer func() { <-ch } // don't return until task is done
task.Start(ctx)
if err := doSomething(task); err != nil {
return err
}
status := <- ch
// do stuff with status
```
Since this channel is created in the `Wait()` calls and never accessible
outside, this should be safe.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Fixes#1431
This adds KillOpts so that a client can specify when they want to kill a
single process or all the processes inside a container.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Fixes#1374
This adds a `LoadProcess` api to load existing exec'd processes from a
task. It allows reattaching of IO and waiting on the process.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Instead of requiring callers to read the struct fields to check for an
error, provide the exit results via a function instead which is more
natural.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
In all of the examples, its recommended to call `Wait()` before starting
a process/task.
Since `Wait()` is a blocking call, this means it must be called from a
goroutine like so:
```go
statusC := make(chan uint32)
go func() {
status, err := task.Wait(ctx)
if err != nil {
// handle async err
}
statusC <- status
}()
task.Start(ctx)
<-statusC
```
This means there is a race here where there is no guarentee when the
goroutine is going to be scheduled, and even a bit more since this
requires an RPC call to be made.
In addition, this code is very messy and a common pattern for any caller
using Wait+Start.
Instead, this changes `Wait()` to use an async model having `Wait()`
return a channel instead of the code itself.
This ensures that when `Wait()` returns that the client has a handle on
the event stream (already made the RPC request) before returning and
reduces any sort of race to how the stream is handled by grpc since we
can't guarentee that we have a goroutine running and blocked on
`Recv()`.
Making `Wait()` async also cleans up the code in the caller drastically:
```go
statusC, err := task.Wait(ctx)
if err != nil {
return err
}
task.Start(ctx)
status := <-statusC
if status.Err != nil {
return err
}
```
No more spinning up goroutines and more natural error
handling for the caller.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Add an option that allows users for force kill and delete a process/task
when calling `Delete`
Fixes#1274
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
This changes Wait() from returning an error whenever you call wait on a
stopped process/task to returning the exit status from the process.
This also adds the exit status to the Status() call on a process/task so
that a user can Wait(), check status, then cancel the wait to avoid
races in event handling.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
This change further plumbs the components required for implementing
event filters. Specifically, we now have the ability to filter on the
`topic` and `namespace`.
In the course of implementing this functionality, it was found that
there were mismatches in the events API that created extra serialization
round trips. A modification to `typeurl.MarshalAny` and a clear
separation between publishing and forwarding allow us to avoid these
serialization issues.
Unfortunately, this has required a few tweaks to the GRPC API, so this
is a breaking change. `Publish` and `Forward` have been clearly separated in
the GRPC API. `Publish` honors the contextual namespace and performs
timestamping while `Forward` simply validates and forwards. The behavior
of `Subscribe` is to propagate events for all namespaces unless
specifically filtered (and hence the relation to this particular change.
The following is an example of using filters to monitor the task events
generated while running the [bucketbench tool](https://github.com/estesp/bucketbench):
```
$ ctr events 'topic~=/tasks/.+,namespace==bb'
...
2017-07-28 22:19:51.78944874 +0000 UTC bb /tasks/start {"container_id":"bb-ctr-6-8","pid":25889}
2017-07-28 22:19:51.791893688 +0000 UTC bb /tasks/start {"container_id":"bb-ctr-4-8","pid":25882}
2017-07-28 22:19:51.792608389 +0000 UTC bb /tasks/start {"container_id":"bb-ctr-2-9","pid":25860}
2017-07-28 22:19:51.793035217 +0000 UTC bb /tasks/start {"container_id":"bb-ctr-5-6","pid":25869}
2017-07-28 22:19:51.802659622 +0000 UTC bb /tasks/start {"container_id":"bb-ctr-0-7","pid":25877}
2017-07-28 22:19:51.805192898 +0000 UTC bb /tasks/start {"container_id":"bb-ctr-3-6","pid":25856}
2017-07-28 22:19:51.832374931 +0000 UTC bb /tasks/exit {"container_id":"bb-ctr-8-6","id":"bb-ctr-8-6","pid":25864,"exited_at":"2017-07-28T22:19:51.832013043Z"}
2017-07-28 22:19:51.84001249 +0000 UTC bb /tasks/exit {"container_id":"bb-ctr-2-9","id":"bb-ctr-2-9","pid":25860,"exited_at":"2017-07-28T22:19:51.839717714Z"}
2017-07-28 22:19:51.840272635 +0000 UTC bb /tasks/exit {"container_id":"bb-ctr-7-6","id":"bb-ctr-7-6","pid":25855,"exited_at":"2017-07-28T22:19:51.839796335Z"}
...
```
In addition to the events changes, we now display the namespace origin
of the event in the cli tool.
This will be followed by a PR to add individual field filtering for the
events API for each event type.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
In the course of setting out to add filters and address some cleanup, it
was found that we had a few problems in the events subsystem that needed
addressing before moving forward.
The biggest change was to move to the more standard terminology of
publish and subscribe. We make this terminology change across the Go
interface and the GRPC API, making the behavior more familier. The
previous system was very context-oriented, which is no longer required.
With this, we've removed a large amount of dead and unneeded code. Event
transactions, context storage and the concept of `Poster` is gone. This
has been replaced in most places with a `Publisher`, which matches the
actual usage throughout the codebase, removing the need for helpers.
There are still some questions around the way events are handled in the
shim. Right now, we've preserved some of the existing bugs which may
require more extensive changes to resolve correctly.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This removes the RuntimeEvent super proto with enums into separate
runtime event protos to be inline with the other events that are output
by containerd.
This also renames the runtime events into Task* events.
Fixes#1071
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
This moves the shim's API and protos out of the containerd services
package and into the linux runtime package. This is because the shim is
an implementation detail of the linux runtime that we have and it is not
a containerd user facing api.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
When using events, it was found to be fairly unwieldy with a number of
extra packages. For the most part, when interacting with the events
service, we want types of the same version of the service. This has been
accomplished by moving all events types into the events package.
In addition, several fixes to the way events are marshaled have been
included. Specifically, we defer to the protobuf type registration
system to assemble events and type urls, with a little bit sheen on top
of add a containerd.io oriented namespace.
This has resulted in much cleaner event consumption and has removed the
reliance on error prone type urls, in favor of concrete types.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
We need a separate API for handing the exit status and deletion of
Exec'd processes to make sure they are properly cleaned up within the
shim and daemon.
Fixes#973
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
