Hijack is incompatible with use of CloseNotifier

[raphink]

This is caused by https://github.com/docker/docker/issues/12845

package main

import (
  "fmt"
  "io/ioutil"

  "github.com/docker/engine-api/client"
  "github.com/docker/engine-api/types"
  "golang.org/x/net/context"
)

// Some basic nginx container running
const ContainerID string = "ce5d8b318ca0"

func main() {
  c, _ := client.NewClient("unix:///var/run/docker.sock", "", nil, nil)

  body, _ := c.ContainerLogs(context.Background(), ContainerID, types.ContainerLogsOptions{
    ShowStdout: true,
    ShowStderr: true,
  })

  defer body.Close()

  // This line causes ContainerExecStart to fail with
  // Error response from daemon: http: Hijack is incompatible with use of CloseNotifier
  _, _ = ioutil.ReadAll(body)

  exec, _ := c.ContainerExecCreate(context.Background(), ContainerID, types.ExecConfig{
    Cmd: []string{"date"},
  })

  err := c.ContainerExecStart(context.Background(), exec.ID, types.ExecStartCheck{})
  fmt.Println(err)
}

$ go run engine-api-bug.go 
Error response from daemon: http: Hijack is incompatible with use of CloseNotifier

How can I fix this with engine-api?

[cpuguy83]

This is likely from connection re-use, which is automatic from the http package.

In the client transport we'll either need to set DisableKeepAlives or maybe in ContainerExecStart we can make sure to set Close in the request?

[raphink]

This should work. Currently, I have to create a new Docker client for the ContainerExecStart.

[cpuguy83]

This could probably be considered a golang bug. We should not have to manually manage this when the http package knows we've hijacked the connection.

[LK4D4]

I belive fix for this was on go1.6 https://github.com/golang/go/commit/99fb19194c03c618c0d8faa87b91ba419ae28ee3

[cpuguy83]

It would seem so. @raphink any chance you can test with go 1.6?

[raphink]

I get this bug with all versions of go, including tip. I think it's the docker engine that needs to be rebuilt with the new version of go.

[thaJeztah]

@cpuguy83 @LK4D4 saw that someone reported this issue on 1.12-rc3 (which uses go 1.6); https://github.com/docker/docker/issues/12845#issuecomment-230592427