Streaming output only happens for -ti flag

[binocarlos]

When I do this using DOCKER_HOST=tcp://127.0.0.1:2375 (i.e. pointing @ powerstrip):

docker run --rm -ti ubuntu echo hello - it outputs hello

But when I do this:

docker run --rm ubuntu echo hello - it outputs nothing

Whereas when I do the same thing without pointing at powerstrip - it outputs hello for both scenarios.

There must be a flag in powerstrip that depends on either -t or -i that enables streaming mode - we need to do this for any attach mode - hope this makes sense.

[lukemarsden]

We've dug into this and the really weird thing is that docker run ubuntu echo hello works (which, I think, relies on the TCP half-close trick here) when powerstrip is run outside a container. When powerstrip is run inside a container, and port 2375 exposed via -p "2375:2375", docker run ubuntu echo hello does not work.

[lukemarsden]

Current hypothesis is that something to do with the Docker iptables NAT rules is interfering with the TCP half-close.

[lukemarsden]

FTR, this is the difference between powerstrip running outside a container (LHS) vs powerstrip running inside a container. This behaviour is the same both with the golang and Twisted versions.

[lukemarsden]

Proposed workaround presently is to make Docker bind to a UNIX socket rather than a port, bypassing the (currently unproven) Docker NAT half-close issues.

[lukemarsden]

Demonstrated working in https://github.com/ClusterHQ/powerstrip/compare/unix-socket