Explicitly set namespace when publishing an event

[kevpar]

This fixes a regression introduced when we switched to TTRPC for
publishing events to containerd. Previously we explicitly passed the
namespace for each event as a command line parameter to containerd.exe,
which was invoked to publish the event. Now that TTRPC is used, the
context passed to Publish is expected to include the namespace as a
stored value.

Signed-off-by: Kevin Parsons kevpar@microsoft.com

[jterry75]

LGTM. Good catch. Any idea why we didnt see this?

[katiewasnothere]

LGTM. @jterry75 I must have missed that the namespaces weren't what they were intended to be when I tested the update to TTRPC.

[kevpar]

I noticed the issue when looking at a trace for a different issue, and saw failed publishEvent spans. Note that a bunch of the events appeared to already have namespace in the context due to using a context passed through from containerd, but any publishing from a background goroutine tended to use context.Background(). We should probably add a test that does container operations and ensures it sees the expected events delivered.