package opts // import "github.com/docker/docker/opts"

 // TODO Windows. Identify bug in GOLang 1.5.1+ and/or Windows Server 2016 TP5.

 // @jhowardmsft, @swernli.
 //
 // On Windows, this mitigates a problem with the default options of running

 // a docker client against a local docker daemon on TP5.

 //
 // What was found that if the default host is "localhost", even if the client
 // (and daemon as this is local) is not physically on a network, and the DNS
 // cache is flushed (ipconfig /flushdns), then the client will pause for
 // exactly one second when connecting to the daemon for calls. For example
 // using docker run windowsservercore cmd, the CLI will send a create followed
 // by an attach. You see the delay between the attach finishing and the attach
 // being seen by the daemon.
 //
 // Here's some daemon debug logs with additional debug spew put in. The
 // AfterWriteJSON log is the very last thing the daemon does as part of the
 // create call. The POST /attach is the second CLI call. Notice the second
 // time gap.
 //
 // time="2015-11-06T13:38:37.259627400-08:00" level=debug msg="After createRootfs"
 // time="2015-11-06T13:38:37.263626300-08:00" level=debug msg="After setHostConfig"
 // time="2015-11-06T13:38:37.267631200-08:00" level=debug msg="before createContainerPl...."

 // time="2015-11-06T13:38:37.271629500-08:00" level=debug msg=ToDiskLocking....

 // time="2015-11-06T13:38:37.275643200-08:00" level=debug msg="loggin event...."
 // time="2015-11-06T13:38:37.277627600-08:00" level=debug msg="logged event...."
 // time="2015-11-06T13:38:37.279631800-08:00" level=debug msg="In defer func"
 // time="2015-11-06T13:38:37.282628100-08:00" level=debug msg="After daemon.create"
 // time="2015-11-06T13:38:37.286651700-08:00" level=debug msg="return 2"
 // time="2015-11-06T13:38:37.289629500-08:00" level=debug msg="Returned from daemon.ContainerCreate"
 // time="2015-11-06T13:38:37.311629100-08:00" level=debug msg="After WriteJSON"
 // ... 1 second gap here....
 // time="2015-11-06T13:38:38.317866200-08:00" level=debug msg="Calling POST /v1.22/containers/984758282b842f779e805664b2c95d563adc9a979c8a3973e68c807843ee4757/attach"
 // 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"
 //
 // We suspect this is either a bug introduced in GOLang 1.5.1, or that a change

 // in GOLang 1.5.1 (from 1.4.3) is exposing a bug in Windows. In theory,

 // the Windows networking stack is supposed to resolve "localhost" internally,
 // without hitting DNS, or even reading the hosts file (which is why localhost
 // is commented out in the hosts file on Windows).
 //
 // We have validated that working around this using the actual IPv4 localhost
 // address does not cause the delay.
 //
 // This does not occur with the docker client built with 1.4.3 on the same

 // Windows build, regardless of whether the daemon is built using 1.5.1

 // or 1.4.3. It does not occur on Linux. We also verified we see the same thing
 // on a cross-compiled Windows binary (from Linux).
 //
 // Final note: This is a mitigation, not a 'real' fix. It is still susceptible

 // to the delay if a user were to do 'docker run -H=tcp://localhost:2375...'

 // explicitly.
 

 // DefaultHTTPHost Default HTTP Host used if only port is provided to -H flag e.g. dockerd -H tcp://:8080

 const DefaultHTTPHost = "127.0.0.1"