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Diffstat (limited to 'vendor/k8s.io/utils/exec/exec.go')
-rw-r--r-- | vendor/k8s.io/utils/exec/exec.go | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/vendor/k8s.io/utils/exec/exec.go b/vendor/k8s.io/utils/exec/exec.go new file mode 100644 index 000000000..3b23eceb1 --- /dev/null +++ b/vendor/k8s.io/utils/exec/exec.go @@ -0,0 +1,202 @@ +/* +Copyright 2017 The Kubernetes 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 exec + +import ( + "io" + osexec "os/exec" + "syscall" + "time" +) + +// ErrExecutableNotFound is returned if the executable is not found. +var ErrExecutableNotFound = osexec.ErrNotFound + +// Interface is an interface that presents a subset of the os/exec API. Use this +// when you want to inject fakeable/mockable exec behavior. +type Interface interface { + // Command returns a Cmd instance which can be used to run a single command. + // This follows the pattern of package os/exec. + Command(cmd string, args ...string) Cmd + + // LookPath wraps os/exec.LookPath + LookPath(file string) (string, error) +} + +// Cmd is an interface that presents an API that is very similar to Cmd from os/exec. +// As more functionality is needed, this can grow. Since Cmd is a struct, we will have +// to replace fields with get/set method pairs. +type Cmd interface { + // Run runs the command to the completion. + Run() error + // CombinedOutput runs the command and returns its combined standard output + // and standard error. This follows the pattern of package os/exec. + CombinedOutput() ([]byte, error) + // Output runs the command and returns standard output, but not standard err + Output() ([]byte, error) + SetDir(dir string) + SetStdin(in io.Reader) + SetStdout(out io.Writer) + SetStderr(out io.Writer) + // Stops the command by sending SIGTERM. It is not guaranteed the + // process will stop before this function returns. If the process is not + // responding, an internal timer function will send a SIGKILL to force + // terminate after 10 seconds. + Stop() +} + +// ExitError is an interface that presents an API similar to os.ProcessState, which is +// what ExitError from os/exec is. This is designed to make testing a bit easier and +// probably loses some of the cross-platform properties of the underlying library. +type ExitError interface { + String() string + Error() string + Exited() bool + ExitStatus() int +} + +// Implements Interface in terms of really exec()ing. +type executor struct{} + +// New returns a new Interface which will os/exec to run commands. +func New() Interface { + return &executor{} +} + +// Command is part of the Interface interface. +func (executor *executor) Command(cmd string, args ...string) Cmd { + return (*cmdWrapper)(osexec.Command(cmd, args...)) +} + +// LookPath is part of the Interface interface +func (executor *executor) LookPath(file string) (string, error) { + return osexec.LookPath(file) +} + +// Wraps exec.Cmd so we can capture errors. +type cmdWrapper osexec.Cmd + +var _ Cmd = &cmdWrapper{} + +func (cmd *cmdWrapper) SetDir(dir string) { + cmd.Dir = dir +} + +func (cmd *cmdWrapper) SetStdin(in io.Reader) { + cmd.Stdin = in +} + +func (cmd *cmdWrapper) SetStdout(out io.Writer) { + cmd.Stdout = out +} + +func (cmd *cmdWrapper) SetStderr(out io.Writer) { + cmd.Stderr = out +} + +// Run is part of the Cmd interface. +func (cmd *cmdWrapper) Run() error { + return (*osexec.Cmd)(cmd).Run() +} + +// CombinedOutput is part of the Cmd interface. +func (cmd *cmdWrapper) CombinedOutput() ([]byte, error) { + out, err := (*osexec.Cmd)(cmd).CombinedOutput() + if err != nil { + return out, handleError(err) + } + return out, nil +} + +func (cmd *cmdWrapper) Output() ([]byte, error) { + out, err := (*osexec.Cmd)(cmd).Output() + if err != nil { + return out, handleError(err) + } + return out, nil +} + +// Stop is part of the Cmd interface. +func (cmd *cmdWrapper) Stop() { + c := (*osexec.Cmd)(cmd) + if c.ProcessState.Exited() { + return + } + c.Process.Signal(syscall.SIGTERM) + time.AfterFunc(10*time.Second, func() { + if c.ProcessState.Exited() { + return + } + c.Process.Signal(syscall.SIGKILL) + }) +} + +func handleError(err error) error { + if ee, ok := err.(*osexec.ExitError); ok { + // Force a compile fail if exitErrorWrapper can't convert to ExitError. + var x ExitError = &ExitErrorWrapper{ee} + return x + } + if ee, ok := err.(*osexec.Error); ok { + if ee.Err == osexec.ErrNotFound { + return ErrExecutableNotFound + } + } + return err +} + +// ExitErrorWrapper is an implementation of ExitError in terms of os/exec ExitError. +// Note: standard exec.ExitError is type *os.ProcessState, which already implements Exited(). +type ExitErrorWrapper struct { + *osexec.ExitError +} + +var _ ExitError = ExitErrorWrapper{} + +// ExitStatus is part of the ExitError interface. +func (eew ExitErrorWrapper) ExitStatus() int { + ws, ok := eew.Sys().(syscall.WaitStatus) + if !ok { + panic("can't call ExitStatus() on a non-WaitStatus exitErrorWrapper") + } + return ws.ExitStatus() +} + +// CodeExitError is an implementation of ExitError consisting of an error object +// and an exit code (the upper bits of os.exec.ExitStatus). +type CodeExitError struct { + Err error + Code int +} + +var _ ExitError = CodeExitError{} + +func (e CodeExitError) Error() string { + return e.Err.Error() +} + +func (e CodeExitError) String() string { + return e.Err.Error() +} + +func (e CodeExitError) Exited() bool { + return true +} + +func (e CodeExitError) ExitStatus() int { + return e.Code +} |