Consoles, consoles, consoles. #1018
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,5 +1,6 @@ | ||
| vendor/pkg | ||
| /runc | ||
| contrib/cmd/recvtty/recvtty | ||
| Godeps/_workspace/src/github.com/opencontainers/runc | ||
| man/man8 | ||
| release |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,247 @@ | ||
| /* | ||
| * Copyright 2016 SUSE LLC | ||
| * | ||
| * Licensed under the Apache License, Version 2.0 (the "License"); | ||
| * you may not use this file except in compliance with the License. | ||
| * You may obtain a copy of the License at | ||
| * | ||
| * http://www.apache.org/licenses/LICENSE-2.0 | ||
| * | ||
| * Unless required by applicable law or agreed to in writing, software | ||
| * distributed under the License is distributed on an "AS IS" BASIS, | ||
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| * See the License for the specific language governing permissions and | ||
| * limitations under the License. | ||
| */ | ||
|
|
||
| package main | ||
|
|
||
| import ( | ||
| "fmt" | ||
| "io" | ||
| "io/ioutil" | ||
| "net" | ||
| "os" | ||
| "strings" | ||
|
|
||
| "github.com/opencontainers/runc/libcontainer" | ||
| "github.com/opencontainers/runc/libcontainer/utils" | ||
| "github.com/urfave/cli" | ||
| ) | ||
|
|
||
| // version will be populated by the Makefile, read from | ||
| // VERSION file of the source code. | ||
| var version = "" | ||
|
|
||
| // gitCommit will be the hash that the binary was built from | ||
| // and will be populated by the Makefile | ||
| var gitCommit = "" | ||
|
|
||
| const ( | ||
| usage = `Open Container Initiative contrib/cmd/recvtty | ||
|
|
||
| recvtty is a reference implementation of a consumer of runC's --console-socket | ||
| API. It has two main modes of operation: | ||
|
|
||
| * single: Only permit one terminal to be sent to the socket, which is | ||
|
There was a problem hiding this comment. From the code below it looks like single is the default. Should probably say that here. There was a problem hiding this comment.
|
||
| then hooked up to the stdio of the recvtty process. This is useful | ||
| for rudimentary shell management of a container. | ||
|
|
||
| * null: Permit as many terminals to be sent to the socket, but they | ||
| are read to /dev/null. This is used for testing, and imitates the | ||
| old runC API's --console=/dev/pts/ptmx hack which would allow for a | ||
| similar trick. This is probably not what you want to use, unless | ||
| you're doing something like our bats integration tests. | ||
|
|
||
| To use recvtty, just specify a socket path at which you want to receive | ||
| terminals: | ||
|
|
||
| $ recvtty [--mode <single|null>] socket.sock | ||
| ` | ||
| ) | ||
|
|
||
| func bail(err error) { | ||
| fmt.Fprintf(os.Stderr, "[recvtty] fatal error: %v\n", err) | ||
| os.Exit(1) | ||
| } | ||
|
|
||
| func handleSingle(path string) error { | ||
| // Open a socket. | ||
| ln, err := net.Listen("unix", path) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| defer ln.Close() | ||
|
|
||
| // We only accept a single connection, since we can only really have | ||
| // one reader for os.Stdin. Plus this is all a PoC. | ||
| conn, err := ln.Accept() | ||
| if err != nil { | ||
| return err | ||
| } | ||
| defer conn.Close() | ||
|
|
||
| // Close ln, to allow for other instances to take over. | ||
| ln.Close() | ||
|
|
||
| // Get the fd of the connection. | ||
| unixconn, ok := conn.(*net.UnixConn) | ||
| if !ok { | ||
| return fmt.Errorf("failed to cast to unixconn") | ||
| } | ||
|
|
||
| socket, err := unixconn.File() | ||
| if err != nil { | ||
| return err | ||
| } | ||
| defer socket.Close() | ||
|
|
||
| // Get the master file descriptor from runC. | ||
| master, err := utils.RecvFd(socket) | ||
| if err != nil { | ||
| return err | ||
| } | ||
|
|
||
| // Print the file descriptor tag. | ||
| ti, err := libcontainer.GetTerminalInfo(master.Name()) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| fmt.Printf("[recvtty] received masterfd: container '%s'\n", ti.ContainerID) | ||
|
|
||
| // Copy from our stdio to the master fd. | ||
| quitChan := make(chan struct{}) | ||
| go func() { | ||
| io.Copy(os.Stdout, master) | ||
| quitChan <- struct{}{} | ||
| }() | ||
| go func() { | ||
| io.Copy(master, os.Stdin) | ||
| quitChan <- struct{}{} | ||
| }() | ||
|
|
||
| // Only close the master fd once we've stopped copying. | ||
| <-quitChan | ||
| master.Close() | ||
| return nil | ||
| } | ||
|
|
||
| func handleNull(path string) error { | ||
| // Open a socket. | ||
| ln, err := net.Listen("unix", path) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| defer ln.Close() | ||
|
|
||
| // As opposed to handleSingle we accept as many connections as we get, but | ||
| // we don't interact with Stdin at all (and we copy stdout to /dev/null). | ||
| for { | ||
| conn, err := ln.Accept() | ||
| if err != nil { | ||
| return err | ||
| } | ||
| go func(conn net.Conn) { | ||
| // Don't leave references lying around. | ||
| defer conn.Close() | ||
|
|
||
| // Get the fd of the connection. | ||
| unixconn, ok := conn.(*net.UnixConn) | ||
| if !ok { | ||
| return | ||
| } | ||
|
|
||
| socket, err := unixconn.File() | ||
| if err != nil { | ||
| return | ||
| } | ||
| defer socket.Close() | ||
|
|
||
| // Get the master file descriptor from runC. | ||
| master, err := utils.RecvFd(socket) | ||
| if err != nil { | ||
| return | ||
| } | ||
|
|
||
| // Print the file descriptor tag. | ||
| ti, err := libcontainer.GetTerminalInfo(master.Name()) | ||
| if err != nil { | ||
| bail(err) | ||
| } | ||
| fmt.Printf("[recvtty] received masterfd: container '%s'\n", ti.ContainerID) | ||
|
|
||
| // Just do a dumb copy to /dev/null. | ||
| devnull, err := os.OpenFile("/dev/null", os.O_RDWR, 0) | ||
| if err != nil { | ||
| // TODO: Handle this nicely. | ||
| return | ||
| } | ||
|
|
||
| io.Copy(devnull, master) | ||
| devnull.Close() | ||
| }(conn) | ||
| } | ||
| } | ||
|
|
||
| func main() { | ||
| app := cli.NewApp() | ||
| app.Name = "recvtty" | ||
| app.Usage = usage | ||
|
|
||
| // Set version to be the same as runC. | ||
| var v []string | ||
| if version != "" { | ||
| v = append(v, version) | ||
| } | ||
| if gitCommit != "" { | ||
| v = append(v, fmt.Sprintf("commit: %s", gitCommit)) | ||
| } | ||
| app.Version = strings.Join(v, "\n") | ||
|
|
||
| // Set the flags. | ||
| app.Flags = []cli.Flag{ | ||
| cli.StringFlag{ | ||
| Name: "mode, m", | ||
| Value: "single", | ||
|
There was a problem hiding this comment. Given null is closer to the prior use cases for runc, is making "single" the best default choice here, or just a limitation given the above mentioned stdin limitation for this mockup client? There was a problem hiding this comment. Just because we used a |
||
| Usage: "Mode of operation (single or null)", | ||
| }, | ||
| cli.StringFlag{ | ||
| Name: "pid-file", | ||
| Value: "", | ||
| Usage: "Path to write daemon process ID to", | ||
| }, | ||
| } | ||
|
|
||
| app.Action = func(ctx *cli.Context) error { | ||
| args := ctx.Args() | ||
| if len(args) != 1 { | ||
| return fmt.Errorf("need to specify a single socket path") | ||
| } | ||
| path := ctx.Args()[0] | ||
|
|
||
| pidPath := ctx.String("pid-file") | ||
| if pidPath != "" { | ||
| pid := fmt.Sprintf("%d\n", os.Getpid()) | ||
| if err := ioutil.WriteFile(pidPath, []byte(pid), 0644); err != nil { | ||
| return err | ||
| } | ||
| } | ||
|
|
||
| switch ctx.String("mode") { | ||
| case "single": | ||
| if err := handleSingle(path); err != nil { | ||
| return err | ||
| } | ||
| case "null": | ||
| if err := handleNull(path); err != nil { | ||
| return err | ||
| } | ||
| default: | ||
| return fmt.Errorf("need to select a valid mode: %s", ctx.String("mode")) | ||
| } | ||
| return nil | ||
| } | ||
| if err := app.Run(os.Args); err != nil { | ||
| bail(err) | ||
| } | ||
| } | ||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
its ok to output recvtty in current directory instead of contrib here i think.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I thought so too, but @hqhq mentioned that it isn't really an "official" binary so I'm on the fence about it.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
i think as long as we dont install it explicitly its ok, but im not sure either
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I was concerned that it might cause confusion that runc depends on this recvtty if we build it under root.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I'm just going to leave it as-is, since it feels marginally safer tucked away so nobody ships it as a serious component of runC. :P