dockertest.Resource.Exec fails with "Unrecognized input header: 100"

[thediveo]

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Ory Network Project

No response

Describe the bug

dockertest.Resource.Exec(..., dockertest.ExecOptions{StdOut: ..., StdErr: ..., TTY: true}) fails with Start exec failed: Unrecognized input header: 100. This happens regardless of whether the corresponding container has been created with or without Tty: true.

Reproducing the bug

By("spinning up a Docker container with stand-alone containerd, courtesy of the KinD k8s sig")
pool := Successful(dockertest.NewPool("unix:///var/run/docker.sock"))
_ = pool.RemoveContainerByName(kindischName)
// The necessary container start arguments come from KinD's Docker node
// provisioner, see:
// https://github.com/kubernetes-sigs/kind/blob/3610f606516ccaa88aa098465d8c13af70937050/pkg/cluster/internal/providers/docker/provision.go#L133
//
// Please note that --privileged already implies switching off AppArmor.
//
// Please note further, that currently some Docker client CLI flags
// don't translate into dockertest-supported options.
//
// docker run -it --rm --name kindisch-...
//   --privileged
//   --cgroupns=private
//   --init=false
//   --volume /dev/mapper:/dev/mapper
//   --device /dev/fuse
//   --tmpfs /tmp
//   --tmpfs /run
//   --volume /var
//   --volume /lib/modules:/lib/modules:ro
//   kindisch-...
providerCntr = Successful(pool.BuildAndRunWithBuildOptions(
    &dockertest.BuildOptions{
	    ContextDir: "./test/kindisch", // sorry, couldn't resist the pun.
	    Dockerfile: "Dockerfile",
	    BuildArgs: []docker.BuildArg{
		    {Name: "KINDEST_BASE_TAG", Value: test.KindestBaseImageTag},
	    },
    },
    &dockertest.RunOptions{
	    Name:       kindischName,
	    Privileged: true,
	    Mounts: []string{
		    "/dev/mapper:/dev/mapper",
		    "/var",
		    "/lib/modules:/lib/modules:ro",
	    },
	    Tty: true,
    }, func(hc *docker.HostConfig) {
	    hc.Init = false
	    hc.Tmpfs = map[string]string{
		    "/tmp": "",
		    "/run": "",
	    }
	    hc.Devices = []docker.Device{
		    {PathOnHost: "/dev/fuse"},
	    }
    }))

func Exec(cntr *dockertest.Resource, args ...string) {
	gi.GinkgoHelper()
	exitCode, err := cntr.Exec(
		append([]string{"ctr"}, args...),
		dockertest.ExecOptions{
			StdOut: gi.GinkgoWriter,
			StdErr: gi.GinkgoWriter,
			TTY:    true,
		},
	)
	g.Expect(err).NotTo(g.HaveOccurred(), "failed: ctr %s", strings.Join(args, " "))
	g.Expect(exitCode).To(g.BeZero(), "ctr command failed with non-zero exit code")
}

Relevant log output

No response

Relevant configuration

No response

Version

v3.10.0

On which operating system are you observing this issue?

Linux

In which environment are you deploying?

Docker

Additional Context

No response

[thediveo]

Never mind bothering with answering this bug issue and even fixing this obvious incompatibility with the Docker API's 100 CONTINUE.

For those stumbling upon the same problem, I've fixed it. I've simply written my own replacment for this module (not a drop-in), using the official Docker Go client, designing a neat function option API that works so much better than anticipated, and large test coverage on top, so I'm now replacing dockertest in company projects as well as my own. Now I have proper diagnosis ouput from builds, container runs, and command execs inside containers whenever a unit test fails. FYI, https://github.com/thediveo/morbyd

The above unit test excerpt now becomes as follows, properly streaming build and container output, without even needing to use a pseudo TTY:

By("spinning up a Docker container with stand-alone containerd, courtesy of the KinD k8s sig")
Expect(sess.BuildImage(ctx, "./_test/kindisch",
	build.WithTag(img.Name),
	build.WithBuildArg("KINDEST_BASE_TAG="+test.KindestBaseImageTag),
	build.WithOutput(timestamper.New(GinkgoWriter)))).
	Error().NotTo(HaveOccurred())
providerCntr = Successful(sess.Run(ctx, img.Name,
	run.WithName(kindischName),
	run.WithAutoRemove(),
	run.WithPrivileged(),
	run.WithSecurityOpt("label=disable"),
	run.WithCgroupnsMode("private"),
	run.WithVolume("/var"),
	run.WithVolume("/dev/mapper:/dev/mapper"),
	run.WithVolume("/lib/modules:/lib/modules:ro"),
	run.WithTmpfs("/tmp"),
	run.WithTmpfs("/run"),
	run.WithDevice("/dev/fuse"),
	run.WithCombinedOutput(timestamper.New(GinkgoWriter))))

Thank you for the fish.