Revert vendor directory to support old golang (GOPATH mode)

gomodule is still in progress to migrate for now, hence multus
team decide to keep vendor directory to support build without
gomodule.
This commit is contained in:
Tomofumi Hayashi
2019-06-14 12:43:43 +09:00
committed by Tomofumi Hayashi
parent de1c1c78e9
commit ac21a96804
1620 changed files with 650833 additions and 1 deletions

201
vendor/github.com/containernetworking/plugins/LICENSE generated vendored Normal file
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### Namespaces, Threads, and Go
On Linux each OS thread can have a different network namespace. Go's thread scheduling model switches goroutines between OS threads based on OS thread load and whether the goroutine would block other goroutines. This can result in a goroutine switching network namespaces without notice and lead to errors in your code.
### Namespace Switching
Switching namespaces with the `ns.Set()` method is not recommended without additional strategies to prevent unexpected namespace changes when your goroutines switch OS threads.
Go provides the `runtime.LockOSThread()` function to ensure a specific goroutine executes on its current OS thread and prevents any other goroutine from running in that thread until the locked one exits. Careful usage of `LockOSThread()` and goroutines can provide good control over which network namespace a given goroutine executes in.
For example, you cannot rely on the `ns.Set()` namespace being the current namespace after the `Set()` call unless you do two things. First, the goroutine calling `Set()` must have previously called `LockOSThread()`. Second, you must ensure `runtime.UnlockOSThread()` is not called somewhere in-between. You also cannot rely on the initial network namespace remaining the current network namespace if any other code in your program switches namespaces, unless you have already called `LockOSThread()` in that goroutine. Note that `LockOSThread()` prevents the Go scheduler from optimally scheduling goroutines for best performance, so `LockOSThread()` should only be used in small, isolated goroutines that release the lock quickly.
### Do() The Recommended Thing
The `ns.Do()` method provides **partial** control over network namespaces for you by implementing these strategies. All code dependent on a particular network namespace (including the root namespace) should be wrapped in the `ns.Do()` method to ensure the correct namespace is selected for the duration of your code. For example:
```go
err = targetNs.Do(func(hostNs ns.NetNS) error {
dummy := &netlink.Dummy{
LinkAttrs: netlink.LinkAttrs{
Name: "dummy0",
},
}
return netlink.LinkAdd(dummy)
})
```
Note this requirement to wrap every network call is very onerous - any libraries you call might call out to network services such as DNS, and all such calls need to be protected after you call `ns.Do()`. All goroutines spawned from within the `ns.Do` will not inherit the new namespace. The CNI plugins all exit very soon after calling `ns.Do()` which helps to minimize the problem.
When a new thread is spawned in Linux, it inherits the namespace of its parent. In versions of go **prior to 1.10**, if the runtime spawns a new OS thread, it picks the parent randomly. If the chosen parent thread has been moved to a new namespace (even temporarily), the new OS thread will be permanently "stuck in the wrong namespace", and goroutines will non-deterministically switch namespaces as they are rescheduled.
In short, **there was no safe way to change network namespaces, even temporarily, from within a long-lived, multithreaded Go process**. If you wish to do this, you must use go 1.10 or greater.
### Creating network namespaces
Earlier versions of this library managed namespace creation, but as CNI does not actually utilize this feature (and it was essentially unmaintained), it was removed. If you're writing a container runtime, you should implement namespace management yourself. However, there are some gotchas when doing so, especially around handling `/var/run/netns`. A reasonably correct reference implementation, borrowed from `rkt`, can be found in `pkg/testutils/netns_linux.go` if you're in need of a source of inspiration.
### Further Reading
- https://github.com/golang/go/wiki/LockOSThread
- http://morsmachine.dk/go-scheduler
- https://github.com/containernetworking/cni/issues/262
- https://golang.org/pkg/runtime/
- https://www.weave.works/blog/linux-namespaces-and-go-don-t-mix

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// Copyright 2015-2017 CNI authors
//
// 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 ns
import (
"fmt"
"os"
"runtime"
"sync"
"syscall"
"golang.org/x/sys/unix"
)
// Returns an object representing the current OS thread's network namespace
func GetCurrentNS() (NetNS, error) {
return GetNS(getCurrentThreadNetNSPath())
}
func getCurrentThreadNetNSPath() string {
// /proc/self/ns/net returns the namespace of the main thread, not
// of whatever thread this goroutine is running on. Make sure we
// use the thread's net namespace since the thread is switching around
return fmt.Sprintf("/proc/%d/task/%d/ns/net", os.Getpid(), unix.Gettid())
}
func (ns *netNS) Close() error {
if err := ns.errorIfClosed(); err != nil {
return err
}
if err := ns.file.Close(); err != nil {
return fmt.Errorf("Failed to close %q: %v", ns.file.Name(), err)
}
ns.closed = true
return nil
}
func (ns *netNS) Set() error {
if err := ns.errorIfClosed(); err != nil {
return err
}
if err := unix.Setns(int(ns.Fd()), unix.CLONE_NEWNET); err != nil {
return fmt.Errorf("Error switching to ns %v: %v", ns.file.Name(), err)
}
return nil
}
type NetNS interface {
// Executes the passed closure in this object's network namespace,
// attempting to restore the original namespace before returning.
// However, since 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(). Also, no code called
// from Do() should call runtime.UnlockOSThread(), or the risk
// of executing code in an incorrect namespace will be greater. See
// https://github.com/golang/go/wiki/LockOSThread for further details.
Do(toRun func(NetNS) error) error
// Sets the current network namespace to this object's network namespace.
// Note that since Go's thread scheduling is highly variable, callers
// cannot guarantee the requested namespace will be the current namespace
// after this function is called; to ensure this wrap operations that
// require the namespace with Do() instead.
Set() error
// Returns the filesystem path representing this object's network namespace
Path() string
// Returns a file descriptor representing this object's network namespace
Fd() uintptr
// Cleans up this instance of the network namespace; if this instance
// is the last user the namespace will be destroyed
Close() error
}
type netNS struct {
file *os.File
closed bool
}
// netNS implements the NetNS interface
var _ NetNS = &netNS{}
const (
// https://github.com/torvalds/linux/blob/master/include/uapi/linux/magic.h
NSFS_MAGIC = 0x6e736673
PROCFS_MAGIC = 0x9fa0
)
type NSPathNotExistErr struct{ msg string }
func (e NSPathNotExistErr) Error() string { return e.msg }
type NSPathNotNSErr struct{ msg string }
func (e NSPathNotNSErr) Error() string { return e.msg }
func IsNSorErr(nspath string) error {
stat := syscall.Statfs_t{}
if err := syscall.Statfs(nspath, &stat); err != nil {
if os.IsNotExist(err) {
err = NSPathNotExistErr{msg: fmt.Sprintf("failed to Statfs %q: %v", nspath, err)}
} else {
err = fmt.Errorf("failed to Statfs %q: %v", nspath, err)
}
return err
}
switch stat.Type {
case PROCFS_MAGIC, NSFS_MAGIC:
return nil
default:
return NSPathNotNSErr{msg: fmt.Sprintf("unknown FS magic on %q: %x", nspath, stat.Type)}
}
}
// Returns an object representing the namespace referred to by @path
func GetNS(nspath string) (NetNS, error) {
err := IsNSorErr(nspath)
if err != nil {
return nil, err
}
fd, err := os.Open(nspath)
if err != nil {
return nil, err
}
return &netNS{file: fd}, nil
}
func (ns *netNS) Path() string {
return ns.file.Name()
}
func (ns *netNS) Fd() uintptr {
return ns.file.Fd()
}
func (ns *netNS) errorIfClosed() error {
if ns.closed {
return fmt.Errorf("%q has already been closed", ns.file.Name())
}
return nil
}
func (ns *netNS) Do(toRun func(NetNS) error) error {
if err := ns.errorIfClosed(); err != nil {
return err
}
containedCall := func(hostNS NetNS) error {
threadNS, err := GetCurrentNS()
if err != nil {
return fmt.Errorf("failed to open current netns: %v", err)
}
defer threadNS.Close()
// switch to target namespace
if err = ns.Set(); err != nil {
return fmt.Errorf("error switching to ns %v: %v", ns.file.Name(), err)
}
defer threadNS.Set() // switch back
return toRun(hostNS)
}
// save a handle to current network namespace
hostNS, err := GetCurrentNS()
if err != nil {
return fmt.Errorf("Failed to open current namespace: %v", err)
}
defer hostNS.Close()
var wg sync.WaitGroup
wg.Add(1)
var innerError error
go func() {
defer wg.Done()
runtime.LockOSThread()
innerError = containedCall(hostNS)
}()
wg.Wait()
return innerError
}
// WithNetNSPath executes the passed closure under the given network
// namespace, restoring the original namespace afterwards.
func WithNetNSPath(nspath string, toRun func(NetNS) error) error {
ns, err := GetNS(nspath)
if err != nil {
return err
}
defer ns.Close()
return ns.Do(toRun)
}

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// Copyright 2016 CNI authors
//
// 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 testutils
import "errors"
// BadReader is an io.Reader which always errors
type BadReader struct {
Error error
}
func (r *BadReader) Read(buffer []byte) (int, error) {
if r.Error != nil {
return 0, r.Error
}
return 0, errors.New("banana")
}
func (r *BadReader) Close() error {
return nil
}

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// Copyright 2016 CNI authors
//
// 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 testutils
import (
"io/ioutil"
"os"
"github.com/containernetworking/cni/pkg/skel"
"github.com/containernetworking/cni/pkg/types"
"github.com/containernetworking/cni/pkg/version"
)
func envCleanup() {
os.Unsetenv("CNI_COMMAND")
os.Unsetenv("CNI_PATH")
os.Unsetenv("CNI_NETNS")
os.Unsetenv("CNI_IFNAME")
os.Unsetenv("CNI_CONTAINERID")
}
func CmdAdd(cniNetns, cniContainerID, cniIfname string, conf []byte, f func() error) (types.Result, []byte, error) {
os.Setenv("CNI_COMMAND", "ADD")
os.Setenv("CNI_PATH", os.Getenv("PATH"))
os.Setenv("CNI_NETNS", cniNetns)
os.Setenv("CNI_IFNAME", cniIfname)
os.Setenv("CNI_CONTAINERID", cniContainerID)
defer envCleanup()
// Redirect stdout to capture plugin result
oldStdout := os.Stdout
r, w, err := os.Pipe()
if err != nil {
return nil, nil, err
}
os.Stdout = w
err = f()
w.Close()
var out []byte
if err == nil {
out, err = ioutil.ReadAll(r)
}
os.Stdout = oldStdout
// Return errors after restoring stdout so Ginkgo will correctly
// emit verbose error information on stdout
if err != nil {
return nil, nil, err
}
// Plugin must return result in same version as specified in netconf
versionDecoder := &version.ConfigDecoder{}
confVersion, err := versionDecoder.Decode(conf)
if err != nil {
return nil, nil, err
}
result, err := version.NewResult(confVersion, out)
if err != nil {
return nil, nil, err
}
return result, out, nil
}
func CmdAddWithArgs(args *skel.CmdArgs, f func() error) (types.Result, []byte, error) {
return CmdAdd(args.Netns, args.ContainerID, args.IfName, args.StdinData, f)
}
func CmdCheck(cniNetns, cniContainerID, cniIfname string, conf []byte, f func() error) error {
os.Setenv("CNI_COMMAND", "CHECK")
os.Setenv("CNI_PATH", os.Getenv("PATH"))
os.Setenv("CNI_NETNS", cniNetns)
os.Setenv("CNI_IFNAME", cniIfname)
os.Setenv("CNI_CONTAINERID", cniContainerID)
defer envCleanup()
return f()
}
func CmdCheckWithArgs(args *skel.CmdArgs, f func() error) error {
return CmdCheck(args.Netns, args.ContainerID, args.IfName, args.StdinData, f)
}
func CmdDel(cniNetns, cniContainerID, cniIfname string, f func() error) error {
os.Setenv("CNI_COMMAND", "DEL")
os.Setenv("CNI_PATH", os.Getenv("PATH"))
os.Setenv("CNI_NETNS", cniNetns)
os.Setenv("CNI_IFNAME", cniIfname)
os.Setenv("CNI_CONTAINERID", cniContainerID)
defer envCleanup()
return f()
}
func CmdDelWithArgs(args *skel.CmdArgs, f func() error) error {
return CmdDel(args.Netns, args.ContainerID, args.IfName, f)
}

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// Copyright 2018 CNI authors
//
// 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 testutils
import (
"crypto/rand"
"fmt"
"os"
"path"
"runtime"
"strings"
"sync"
"github.com/containernetworking/plugins/pkg/ns"
"golang.org/x/sys/unix"
)
const nsRunDir = "/var/run/netns"
// Creates a new persistent (bind-mounted) network namespace and returns an object
// representing that namespace, without switching to it.
func NewNS() (ns.NetNS, error) {
b := make([]byte, 16)
_, err := rand.Reader.Read(b)
if err != nil {
return nil, fmt.Errorf("failed to generate random netns name: %v", err)
}
// Create the directory for mounting network namespaces
// This needs to be a shared mountpoint in case it is mounted in to
// other namespaces (containers)
err = os.MkdirAll(nsRunDir, 0755)
if err != nil {
return nil, err
}
// Remount the namespace directory shared. This will fail if it is not
// already a mountpoint, so bind-mount it on to itself to "upgrade" it
// to a mountpoint.
err = unix.Mount("", nsRunDir, "none", unix.MS_SHARED|unix.MS_REC, "")
if err != nil {
if err != unix.EINVAL {
return nil, fmt.Errorf("mount --make-rshared %s failed: %q", nsRunDir, err)
}
// Recursively remount /var/run/netns on itself. The recursive flag is
// so that any existing netns bindmounts are carried over.
err = unix.Mount(nsRunDir, nsRunDir, "none", unix.MS_BIND|unix.MS_REC, "")
if err != nil {
return nil, fmt.Errorf("mount --rbind %s %s failed: %q", nsRunDir, nsRunDir, err)
}
// Now we can make it shared
err = unix.Mount("", nsRunDir, "none", unix.MS_SHARED|unix.MS_REC, "")
if err != nil {
return nil, fmt.Errorf("mount --make-rshared %s failed: %q", nsRunDir, err)
}
}
nsName := fmt.Sprintf("cnitest-%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:])
// create an empty file at the mount point
nsPath := path.Join(nsRunDir, nsName)
mountPointFd, err := os.Create(nsPath)
if err != nil {
return nil, err
}
mountPointFd.Close()
// Ensure the mount point is cleaned up on errors; if the namespace
// was successfully mounted this will have no effect because the file
// is in-use
defer os.RemoveAll(nsPath)
var wg sync.WaitGroup
wg.Add(1)
// do namespace work in a dedicated goroutine, so that we can safely
// Lock/Unlock OSThread without upsetting the lock/unlock state of
// the caller of this function
go (func() {
defer wg.Done()
runtime.LockOSThread()
// Don't unlock. By not unlocking, golang will kill the OS thread when the
// goroutine is done (for go1.10+)
var origNS ns.NetNS
origNS, err = ns.GetNS(getCurrentThreadNetNSPath())
if err != nil {
return
}
defer origNS.Close()
// create a new netns on the current thread
err = unix.Unshare(unix.CLONE_NEWNET)
if err != nil {
return
}
// Put this thread back to the orig ns, since it might get reused (pre go1.10)
defer origNS.Set()
// bind mount the netns from the current thread (from /proc) onto the
// mount point. This causes the namespace to persist, even when there
// are no threads in the ns.
err = unix.Mount(getCurrentThreadNetNSPath(), nsPath, "none", unix.MS_BIND, "")
if err != nil {
err = fmt.Errorf("failed to bind mount ns at %s: %v", nsPath, err)
}
})()
wg.Wait()
if err != nil {
return nil, fmt.Errorf("failed to create namespace: %v", err)
}
return ns.GetNS(nsPath)
}
// UnmountNS unmounts the NS held by the netns object
func UnmountNS(ns ns.NetNS) error {
nsPath := ns.Path()
// Only unmount if it's been bind-mounted (don't touch namespaces in /proc...)
if strings.HasPrefix(nsPath, nsRunDir) {
if err := unix.Unmount(nsPath, 0); err != nil {
return fmt.Errorf("failed to unmount NS: at %s: %v", nsPath, err)
}
if err := os.Remove(nsPath); err != nil {
return fmt.Errorf("failed to remove ns path %s: %v", nsPath, err)
}
}
return nil
}
// getCurrentThreadNetNSPath copied from pkg/ns
func getCurrentThreadNetNSPath() string {
// /proc/self/ns/net returns the namespace of the main thread, not
// of whatever thread this goroutine is running on. Make sure we
// use the thread's net namespace since the thread is switching around
return fmt.Sprintf("/proc/%d/task/%d/ns/net", os.Getpid(), unix.Gettid())
}

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@@ -0,0 +1,55 @@
// Copyright 2017 CNI authors
//
// 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 testutils
import (
"bytes"
"fmt"
"os/exec"
"strconv"
"syscall"
)
// Ping shells out to the `ping` command. Returns nil if successful.
func Ping(saddr, daddr string, isV6 bool, timeoutSec int) error {
args := []string{
"-c", "1",
"-W", strconv.Itoa(timeoutSec),
"-I", saddr,
daddr,
}
bin := "ping"
if isV6 {
bin = "ping6"
}
cmd := exec.Command(bin, args...)
var stderr bytes.Buffer
cmd.Stderr = &stderr
if err := cmd.Run(); err != nil {
switch e := err.(type) {
case *exec.ExitError:
return fmt.Errorf("%v exit status %d: %s",
args, e.Sys().(syscall.WaitStatus).ExitStatus(),
stderr.String())
default:
return err
}
}
return nil
}