| package opts // import "github.com/docker/docker/opts" | |
| const ( | |
| // TODO Windows. Identify bug in GOLang 1.5.1+ and/or Windows Server 2016 TP5. | |
| // | |
| // 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 | |
| DefaultHTTPHost = "127.0.0.1" | |
| // DefaultHost constant defines the default host string used by docker on Windows | |
| DefaultHost = "npipe://" + DefaultNamedPipe | |
| ) |