1. docker
  2. Commit 6a5393636e358173e17275d3bd64218f6157f01d
Browse code

opts: unify host-options, and use consts

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Sebastiaan van Stijn authored on 2020/11/01 00:44:21
Showing 4 changed files
opts/hosts_unix.go
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 package opts // import "github.com/docker/docker/opts"
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-import "fmt"
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+const (
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+	// DefaultHTTPHost Default HTTP Host used if only port is provided to -H flag e.g. dockerd -H tcp://:8080
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+	DefaultHTTPHost = "localhost"
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-// DefaultHost constant defines the default host string used by docker on other hosts than Windows
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-var DefaultHost = fmt.Sprintf("unix://%s", DefaultUnixSocket)
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+	// DefaultHost constant defines the default host string used by docker on other hosts than Windows
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+	DefaultHost = "unix://" + DefaultUnixSocket
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+)
opts/hosts_windows.go
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@@ -1,4 +1,60 @@
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 package opts // import "github.com/docker/docker/opts"
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-// DefaultHost constant defines the default host string used by docker on Windows
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-var DefaultHost = "npipe://" + DefaultNamedPipe
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+const (
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+	// TODO Windows. Identify bug in GOLang 1.5.1+ and/or Windows Server 2016 TP5.
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+	//
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+	// On Windows, this mitigates a problem with the default options of running
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+	// a docker client against a local docker daemon on TP5.
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+	//
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+	// What was found that if the default host is "localhost", even if the client
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+	// (and daemon as this is local) is not physically on a network, and the DNS
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+	// cache is flushed (ipconfig /flushdns), then the client will pause for
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+	// exactly one second when connecting to the daemon for calls. For example
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+	// using docker run windowsservercore cmd, the CLI will send a create followed
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+	// by an attach. You see the delay between the attach finishing and the attach
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+	// being seen by the daemon.
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+	//
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+	// Here's some daemon debug logs with additional debug spew put in. The
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+	// AfterWriteJSON log is the very last thing the daemon does as part of the
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+	// create call. The POST /attach is the second CLI call. Notice the second
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+	// time gap.
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+	//
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+	// time="2015-11-06T13:38:37.259627400-08:00" level=debug msg="After createRootfs"
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+	// time="2015-11-06T13:38:37.263626300-08:00" level=debug msg="After setHostConfig"
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+	// time="2015-11-06T13:38:37.267631200-08:00" level=debug msg="before createContainerPl...."
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+	// time="2015-11-06T13:38:37.271629500-08:00" level=debug msg=ToDiskLocking....
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+	// time="2015-11-06T13:38:37.275643200-08:00" level=debug msg="loggin event...."
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+	// time="2015-11-06T13:38:37.277627600-08:00" level=debug msg="logged event...."
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+	// time="2015-11-06T13:38:37.279631800-08:00" level=debug msg="In defer func"
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+	// time="2015-11-06T13:38:37.282628100-08:00" level=debug msg="After daemon.create"
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+	// time="2015-11-06T13:38:37.286651700-08:00" level=debug msg="return 2"
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+	// time="2015-11-06T13:38:37.289629500-08:00" level=debug msg="Returned from daemon.ContainerCreate"
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+	// time="2015-11-06T13:38:37.311629100-08:00" level=debug msg="After WriteJSON"
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+	// ... 1 second gap here....
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+	// time="2015-11-06T13:38:38.317866200-08:00" level=debug msg="Calling POST /v1.22/containers/984758282b842f779e805664b2c95d563adc9a979c8a3973e68c807843ee4757/attach"
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+	// 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"
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+	//
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+	// We suspect this is either a bug introduced in GOLang 1.5.1, or that a change
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+	// in GOLang 1.5.1 (from 1.4.3) is exposing a bug in Windows. In theory,
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+	// the Windows networking stack is supposed to resolve "localhost" internally,
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+	// without hitting DNS, or even reading the hosts file (which is why localhost
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+	// is commented out in the hosts file on Windows).
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+	//
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+	// We have validated that working around this using the actual IPv4 localhost
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+	// address does not cause the delay.
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+	//
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+	// This does not occur with the docker client built with 1.4.3 on the same
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+	// Windows build, regardless of whether the daemon is built using 1.5.1
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+	// or 1.4.3. It does not occur on Linux. We also verified we see the same thing
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+	// on a cross-compiled Windows binary (from Linux).
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+	//
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+	// Final note: This is a mitigation, not a 'real' fix. It is still susceptible
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+	// to the delay if a user were to do 'docker run -H=tcp://localhost:2375...'
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+	// explicitly.
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+
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+	// DefaultHTTPHost Default HTTP Host used if only port is provided to -H flag e.g. dockerd -H tcp://:8080
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+	DefaultHTTPHost = "127.0.0.1"
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+
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+	// DefaultHost constant defines the default host string used by docker on Windows
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+	DefaultHost = "npipe://" + DefaultNamedPipe
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+)
opts/opts_unix.go
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-// +build !windows
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-
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-package opts // import "github.com/docker/docker/opts"
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-
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-// DefaultHTTPHost Default HTTP Host used if only port is provided to -H flag e.g. dockerd -H tcp://:8080
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-const DefaultHTTPHost = "localhost"
opts/opts_windows.go
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deleted file mode 100644
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@@ -1,55 +0,0 @@
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-package opts // import "github.com/docker/docker/opts"
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-
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-// TODO Windows. Identify bug in GOLang 1.5.1+ and/or Windows Server 2016 TP5.
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-//
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-// On Windows, this mitigates a problem with the default options of running
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-// a docker client against a local docker daemon on TP5.
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-//
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-// What was found that if the default host is "localhost", even if the client
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-// (and daemon as this is local) is not physically on a network, and the DNS
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-// cache is flushed (ipconfig /flushdns), then the client will pause for
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-// exactly one second when connecting to the daemon for calls. For example
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-// using docker run windowsservercore cmd, the CLI will send a create followed
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-// by an attach. You see the delay between the attach finishing and the attach
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-// being seen by the daemon.
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-//
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-// Here's some daemon debug logs with additional debug spew put in. The
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-// AfterWriteJSON log is the very last thing the daemon does as part of the
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-// create call. The POST /attach is the second CLI call. Notice the second
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-// time gap.
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-//
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-// time="2015-11-06T13:38:37.259627400-08:00" level=debug msg="After createRootfs"
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-// time="2015-11-06T13:38:37.263626300-08:00" level=debug msg="After setHostConfig"
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-// time="2015-11-06T13:38:37.267631200-08:00" level=debug msg="before createContainerPl...."
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-// time="2015-11-06T13:38:37.271629500-08:00" level=debug msg=ToDiskLocking....
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-// time="2015-11-06T13:38:37.275643200-08:00" level=debug msg="loggin event...."
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-// time="2015-11-06T13:38:37.277627600-08:00" level=debug msg="logged event...."
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-// time="2015-11-06T13:38:37.279631800-08:00" level=debug msg="In defer func"
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-// time="2015-11-06T13:38:37.282628100-08:00" level=debug msg="After daemon.create"
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-// time="2015-11-06T13:38:37.286651700-08:00" level=debug msg="return 2"
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-// time="2015-11-06T13:38:37.289629500-08:00" level=debug msg="Returned from daemon.ContainerCreate"
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-// time="2015-11-06T13:38:37.311629100-08:00" level=debug msg="After WriteJSON"
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-// ... 1 second gap here....
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-// time="2015-11-06T13:38:38.317866200-08:00" level=debug msg="Calling POST /v1.22/containers/984758282b842f779e805664b2c95d563adc9a979c8a3973e68c807843ee4757/attach"
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-// 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"
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-//
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-// We suspect this is either a bug introduced in GOLang 1.5.1, or that a change
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-// in GOLang 1.5.1 (from 1.4.3) is exposing a bug in Windows. In theory,
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-// the Windows networking stack is supposed to resolve "localhost" internally,
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-// without hitting DNS, or even reading the hosts file (which is why localhost
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-// is commented out in the hosts file on Windows).
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-//
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-// We have validated that working around this using the actual IPv4 localhost
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-// address does not cause the delay.
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-//
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-// This does not occur with the docker client built with 1.4.3 on the same
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-// Windows build, regardless of whether the daemon is built using 1.5.1
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-// or 1.4.3. It does not occur on Linux. We also verified we see the same thing
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-// on a cross-compiled Windows binary (from Linux).
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-//
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-// Final note: This is a mitigation, not a 'real' fix. It is still susceptible
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-// to the delay if a user were to do 'docker run -H=tcp://localhost:2375...'
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-// explicitly.
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-
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-// DefaultHTTPHost Default HTTP Host used if only port is provided to -H flag e.g. dockerd -H tcp://:8080
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-const DefaultHTTPHost = "127.0.0.1"