vendor/github.com/fsouza/go-dockerclient/external/github.com/docker/docker/opts/opts_windows.go

   1 package opts
   2
   3 // TODO Windows. Identify bug in GOLang 1.5.1 and/or Windows Server 2016 TP4.
   4 // @jhowardmsft, @swernli.
   5 //
   6 // On Windows, this mitigates a problem with the default options of running
   7 // a docker client against a local docker daemon on TP4.
   8 //
   9 // What was found that if the default host is "localhost", even if the client
  10 // (and daemon as this is local) is not physically on a network, and the DNS
  11 // cache is flushed (ipconfig /flushdns), then the client will pause for
  12 // exactly one second when connecting to the daemon for calls. For example
  13 // using docker run windowsservercore cmd, the CLI will send a create followed
  14 // by an attach. You see the delay between the attach finishing and the attach
  15 // being seen by the daemon.
  16 //
  17 // Here's some daemon debug logs with additional debug spew put in. The
  18 // AfterWriteJSON log is the very last thing the daemon does as part of the
  19 // create call. The POST /attach is the second CLI call. Notice the second
  20 // time gap.
  21 //
  22 // time="2015-11-06T13:38:37.259627400-08:00" level=debug msg="After createRootfs"
  23 // time="2015-11-06T13:38:37.263626300-08:00" level=debug msg="After setHostConfig"
  24 // time="2015-11-06T13:38:37.267631200-08:00" level=debug msg="before createContainerPl...."
  25 // time="2015-11-06T13:38:37.271629500-08:00" level=debug msg=ToDiskLocking....
  26 // time="2015-11-06T13:38:37.275643200-08:00" level=debug msg="loggin event...."
  27 // time="2015-11-06T13:38:37.277627600-08:00" level=debug msg="logged event...."
  28 // time="2015-11-06T13:38:37.279631800-08:00" level=debug msg="In defer func"
  29 // time="2015-11-06T13:38:37.282628100-08:00" level=debug msg="After daemon.create"
  30 // time="2015-11-06T13:38:37.286651700-08:00" level=debug msg="return 2"
  31 // time="2015-11-06T13:38:37.289629500-08:00" level=debug msg="Returned from daemon.ContainerCreate"
  32 // time="2015-11-06T13:38:37.311629100-08:00" level=debug msg="After WriteJSON"
  33 // ... 1 second gap here....
  34 // time="2015-11-06T13:38:38.317866200-08:00" level=debug msg="Calling POST /v1.22/containers/984758282b842f779e805664b2c95d563adc9a979c8a3973e68c807843ee4757/attach"
  35 // time="2015-11-06T13:38:38.326882500-08:00" level=info msg="POST /v1.22/containers/984758282b842f779e805664b2c95d563adc9a979c8a3973e68c807843ee4757/attach?stderr=1&stdin=1&stdout=1&stream=1"
  36 //
  37 // We suspect this is either a bug introduced in GOLang 1.5.1, or that a change
  38 // in GOLang 1.5.1 (from 1.4.3) is exposing a bug in Windows TP4. In theory,
  39 // the Windows networking stack is supposed to resolve "localhost" internally,
  40 // without hitting DNS, or even reading the hosts file (which is why localhost
  41 // is commented out in the hosts file on Windows).
  42 //
  43 // We have validated that working around this using the actual IPv4 localhost
  44 // address does not cause the delay.
  45 //
  46 // This does not occur with the docker client built with 1.4.3 on the same
  47 // Windows TP4 build, regardless of whether the daemon is built using 1.5.1
  48 // or 1.4.3. It does not occur on Linux. We also verified we see the same thing
  49 // on a cross-compiled Windows binary (from Linux).
  50 //
  51 // Final note: This is a mitigation, not a 'real' fix. It is still susceptible
  52 // to the delay in TP4 if a user were to do 'docker run -H=tcp://localhost:2375...'
  53 // explicitly.
  54
  55 // DefaultHTTPHost Default HTTP Host used if only port is provided to -H flag e.g. docker daemon -H tcp://:8080
  56 const DefaultHTTPHost = "127.0.0.1"