-
Notifications
You must be signed in to change notification settings - Fork 81
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
coordinator: ensure detect gateway and ip conflict in pod's netns
The coordinator plugin uses errgroup to concurrently check the reachability of gateways and whether IP addresses conflict.However, when launching goroutines in [netns.Do]("github.com/containernetworking/plugins/pkg/ns"), the Go runtime cannot guarantee that the code will be executed in the specified network namespace. Therefore, we modified the Go method of errgroup: manually switch to the target network namespace when launching a goroutine and return to the original network namespace after execution.- Loading branch information
Showing
339 changed files
with
1,287 additions
and
2,604 deletions.
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
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
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 +1,10 @@ | ||
| # errgroup | ||
|
|
||
| ## Background | ||
|
|
||
| This file originates from "golang.org/x/sync/errgroup". The coordinator plugin uses errgroup to concurrently check the reachability of gateways and whether IP addresses conflict. | ||
| However, when launching goroutines in [netns.Do]("github.com/containernetworking/plugins/pkg/ns"), the Go runtime cannot guarantee that the code will be executed in the specified | ||
| network namespace. Therefore, we modified the `Go()` method of errgroup: manually switch to the target network namespace when launching a goroutine and return to the original network | ||
| namespace after execution. | ||
|
|
||
| Please see `errgroup.go` to find more details. |
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 +1,111 @@ | ||
| // Copyright 2023 Authors of spidernet-io | ||
| // SPDX-License-Identifier: Apache-2.0 | ||
|
|
||
| // Copyright 2016 The Go Authors. All rights reserved. | ||
| // Use of this source code is governed by a BSD-style | ||
| // license that can be found in the LICENSE file. | ||
|
|
||
| // Package errgroup provides synchronization, error propagation, and Context | ||
| // cancellation for groups of goroutines working on subtasks of a common task. | ||
|
|
||
| package errgroup | ||
|
|
||
| import ( | ||
| "fmt" | ||
| "runtime" | ||
| "sync" | ||
|
|
||
| "github.com/containernetworking/plugins/pkg/ns" | ||
| ) | ||
|
|
||
| type token struct{} | ||
|
|
||
| // A Group is a collection of goroutines working on subtasks that are part of | ||
| // the same overall task. | ||
| // | ||
| // A zero Group is valid, has no limit on the number of active goroutines, | ||
| // and does not cancel on error. | ||
| type Group struct { | ||
| cancel func(error) | ||
|
|
||
| wg sync.WaitGroup | ||
|
|
||
| sem chan token | ||
|
|
||
| errOnce sync.Once | ||
| err error | ||
| } | ||
|
|
||
| func (g *Group) done() { | ||
| if g.sem != nil { | ||
| <-g.sem | ||
| } | ||
| g.wg.Done() | ||
| } | ||
|
|
||
| // Wait blocks until all function calls from the Go method have returned, then | ||
| // returns the first non-nil error (if any) from them. | ||
| func (g *Group) Wait() error { | ||
| g.wg.Wait() | ||
| if g.cancel != nil { | ||
| g.cancel(g.err) | ||
| } | ||
| return g.err | ||
| } | ||
|
|
||
| // Go calls the given function in a new goroutine. | ||
| // It blocks until the new goroutine can be added without the number of | ||
| // active goroutines in the group exceeding the configured limit. | ||
| // | ||
| // The first call to return a non-nil error cancels the group's context, if the | ||
| // group was created by calling WithContext. The error will be returned by Wait. | ||
| // | ||
| // UPDATED: golang each OS thread can have a different | ||
| // network namespace, and Go's thread scheduling is highly | ||
| // variable, callers cannot guarantee any specific namespace | ||
| // is set unless operations that require that namespace are | ||
| // wrapped with Do(). | ||
| // see https://github.com/golang/go/wiki/LockOSThread and | ||
| // https://www.weave.works/blog/linux-namespaces-golang-followup | ||
| // to more details. | ||
| func (g *Group) Go(srcNs, targetNs ns.NetNS, f func() error) { | ||
| if g.sem != nil { | ||
| g.sem <- token{} | ||
| } | ||
|
|
||
| g.wg.Add(1) | ||
| go func() { | ||
| defer g.done() | ||
| runtime.LockOSThread() | ||
|
|
||
| // switch to pod's netns | ||
| if err := targetNs.Set(); err != nil { | ||
| g.errOnce.Do(func() { | ||
| g.err = fmt.Errorf("failed to switch to pod's netns: %v", err) | ||
| if g.cancel != nil { | ||
| g.cancel(g.err) | ||
| } | ||
| }) | ||
| } | ||
|
|
||
| defer func() { | ||
| err := srcNs.Set() // switch back | ||
| if err == nil { | ||
| // Unlock the current thread only when we successfully switched back | ||
| // to the original namespace; otherwise leave the thread locked which | ||
| // will force the runtime to scrap the current thread, that is maybe | ||
| // not as optimal but at least always safe to do. | ||
| runtime.UnlockOSThread() | ||
| } | ||
| }() | ||
|
|
||
| if err := f(); err != nil { | ||
| g.errOnce.Do(func() { | ||
| g.err = err | ||
| if g.cancel != nil { | ||
| g.cancel(g.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
Oops, something went wrong.