github.com/ssdev-go/moby@v17.12.1-ce-rc2+incompatible/opts/opts_windows.go (about)

     1  package opts
     2  
     3  // TODO Windows. Identify bug in GOLang 1.5.1+ and/or Windows Server 2016 TP5.
     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 TP5.
     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. 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 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 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. dockerd -H tcp://:8080
    56  const DefaultHTTPHost = "127.0.0.1"