diff --git a/commands.go b/commands.go index 936b23fea2..7f8f9eec0b 100644 --- a/commands.go +++ b/commands.go @@ -1311,6 +1311,18 @@ func (cli *DockerCli) CmdRun(args ...string) error { return nil } + var containerIDFile *os.File + if len(hostConfig.ContainerIDFile) > 0 { + if _, err := ioutil.ReadFile(hostConfig.ContainerIDFile); err == nil { + return fmt.Errorf("cid file found, make sure the other container isn't running or delete %s", hostConfig.ContainerIDFile) + } + containerIDFile, err = os.Create(hostConfig.ContainerIDFile) + if err != nil { + return fmt.Errorf("failed to create the container ID file: %s", err) + } + defer containerIDFile.Close() + } + //create the container body, statusCode, err := cli.call("POST", "/containers/create", config) //if image not found try to pull it @@ -1341,6 +1353,11 @@ func (cli *DockerCli) CmdRun(args ...string) error { for _, warning := range runResult.Warnings { fmt.Fprintf(cli.err, "WARNING: %s\n", warning) } + if len(hostConfig.ContainerIDFile) > 0 { + if _, err = containerIDFile.WriteString(runResult.ID); err != nil { + return fmt.Errorf("failed to write the container ID to the file: %s", err) + } + } //start the container if _, _, err = cli.call("POST", "/containers/"+runResult.ID+"/start", hostConfig); err != nil { diff --git a/container.go b/container.go index 95c5ba0f72..4443ad52a3 100644 --- a/container.go +++ b/container.go @@ -80,7 +80,8 @@ type Config struct { } type HostConfig struct { - Binds []string + Binds []string + ContainerIDFile string } type BindMap struct { @@ -103,6 +104,7 @@ func ParseRun(args []string, capabilities *Capabilities) (*Config, *HostConfig, flStdin := cmd.Bool("i", false, "Keep stdin open even if not attached") flTty := cmd.Bool("t", false, "Allocate a pseudo-tty") flMemory := cmd.Int64("m", 0, "Memory limit (in bytes)") + flContainerIDFile := cmd.String("cidfile", "", "Write the container ID to the file") if capabilities != nil && *flMemory > 0 && !capabilities.MemoryLimit { //fmt.Fprintf(stdout, "WARNING: Your kernel does not support memory limit capabilities. Limitation discarded.\n") @@ -190,7 +192,8 @@ func ParseRun(args []string, capabilities *Capabilities) (*Config, *HostConfig, Entrypoint: entrypoint, } hostConfig := &HostConfig{ - Binds: binds, + Binds: binds, + ContainerIDFile: *flContainerIDFile, } if capabilities != nil && *flMemory > 0 && !capabilities.SwapLimit { diff --git a/docs/sources/commandline/command/run.rst b/docs/sources/commandline/command/run.rst index 1a14a9b616..19efd85821 100644 --- a/docs/sources/commandline/command/run.rst +++ b/docs/sources/commandline/command/run.rst @@ -14,6 +14,7 @@ -a=map[]: Attach to stdin, stdout or stderr. -c=0: CPU shares (relative weight) + -cidfile="": Write the container ID to the file -d=false: Detached mode: leave the container running in the background -e=[]: Set environment variables -h="": Container host name @@ -26,3 +27,13 @@ -v=[]: Create a bind mount with: [host-dir]:[container-dir]:[rw|ro]. If "host-dir" is missing, then docker creates a new volume. -volumes-from="": Mount all volumes from the given container. -entrypoint="": Overwrite the default entrypoint set by the image. + + +Examples +-------- + +.. code-block:: bash + + docker run -cidfile /tmp/docker_test.cid ubuntu echo "test" + +| This will create a container and print "test" to the console. The cidfile flag makes docker attempt to create a new file and write the container ID to it. If the file exists already, docker will return an error. Docker will close this file when docker run exits.