github/kubernetes
1
0
Fork 0
mirror of https://github.com/k3s-io/kubernetes.git synced 2025-08-03 01:06:27 +00:00
Code Issues Projects Releases Wiki Activity

Always return exec command output

Browse Source 
Always return exec command output, even if the command invocation returns nonzero. This applies to
exec probes and kubelet RunInContainer calls.
This commit is contained in:
Andy Goldstein 2016-08-16 21:41:26 -04:00
parent 7b762fb34b
commit c3fe759fec
4 changed files with 151 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
pkg/kubelet/kubelet.go
View File

@ -2880,11 +2880,10 @@ func (kl *Kubelet) RunInContainer(podFullName string, podUID types.UID, containe
var buffer bytes.Buffer
output := ioutils.WriteCloserWrapper(&buffer)
err = kl.runner.ExecInContainer(container.ID, cmd, nil, output, output, false, nil)
if err != nil {
return nil, err
}
return buffer.Bytes(), nil
// Even if err is non-nil, there still may be output (e.g. the exec wrote to stdout or stderr but
// the command returned a nonzero exit code). Therefore, always return the output along with the
// error.
return buffer.Bytes(), err
}
// ExecInContainer executes a command in a container, connecting the supplied

76
pkg/kubelet/kubelet_test.go
View File

@ -18,6 +18,7 @@ package kubelet
import (
"bytes"
"errors"
"fmt"
"io"
"io/ioutil"
@ -975,6 +976,7 @@ func TestMakeVolumeMounts(t *testing.T) {
}
type fakeContainerCommandRunner struct {
// what was passed in
Cmd []string
ID kubecontainer.ContainerID
PodID types.UID
@ -985,15 +987,25 @@ type fakeContainerCommandRunner struct {
TTY bool
Port uint16
Stream io.ReadWriteCloser
// what to return
StdoutData string
StderrData string
}
func (f *fakeContainerCommandRunner) ExecInContainer(id kubecontainer.ContainerID, cmd []string, in io.Reader, out, err io.WriteCloser, tty bool, resize <-chan term.Size) error {
// record params
f.Cmd = cmd
f.ID = id
f.Stdin = in
f.Stdout = out
f.Stderr = err
f.TTY = tty
// Copy stdout/stderr data
fmt.Fprint(out, f.StdoutData)
fmt.Fprint(out, f.StderrData)
return f.E
}
@ -1027,35 +1039,45 @@ func TestRunInContainerNoSuchPod(t *testing.T) {
}
func TestRunInContainer(t *testing.T) {
testKubelet := newTestKubelet(t, false /* controllerAttachDetachEnabled */)
kubelet := testKubelet.kubelet
fakeRuntime := testKubelet.fakeRuntime
fakeCommandRunner := fakeContainerCommandRunner{}
kubelet.runner = &fakeCommandRunner
for _, testError := range []error{nil, errors.New("foo")} {
testKubelet := newTestKubelet(t, false /* controllerAttachDetachEnabled */)
kubelet := testKubelet.kubelet
fakeRuntime := testKubelet.fakeRuntime
fakeCommandRunner := fakeContainerCommandRunner{
E: testError,
StdoutData: "foo",
StderrData: "bar",
}
kubelet.runner = &fakeCommandRunner
containerID := kubecontainer.ContainerID{Type: "test", ID: "abc1234"}
fakeRuntime.PodList = []*containertest.FakePod{
{Pod: &kubecontainer.Pod{
ID: "12345678",
Name: "podFoo",
Namespace: "nsFoo",
Containers: []*kubecontainer.Container{
{Name: "containerFoo",
ID: containerID,
containerID := kubecontainer.ContainerID{Type: "test", ID: "abc1234"}
fakeRuntime.PodList = []*containertest.FakePod{
{Pod: &kubecontainer.Pod{
ID: "12345678",
Name: "podFoo",
Namespace: "nsFoo",
Containers: []*kubecontainer.Container{
{Name: "containerFoo",
ID: containerID,
},
},
},
}},
}
cmd := []string{"ls"}
_, err := kubelet.RunInContainer("podFoo_nsFoo", "", "containerFoo", cmd)
if fakeCommandRunner.ID != containerID {
t.Errorf("unexpected Name: %s", fakeCommandRunner.ID)
}
if !reflect.DeepEqual(fakeCommandRunner.Cmd, cmd) {
t.Errorf("unexpected command: %s", fakeCommandRunner.Cmd)
}
if err != nil {
t.Errorf("unexpected error: %v", err)
}},
}
cmd := []string{"ls"}
actualOutput, err := kubelet.RunInContainer("podFoo_nsFoo", "", "containerFoo", cmd)
if fakeCommandRunner.ID != containerID {
t.Errorf("(testError=%v) unexpected Name: %s", testError, fakeCommandRunner.ID)
}
if !reflect.DeepEqual(fakeCommandRunner.Cmd, cmd) {
t.Errorf("(testError=%v) unexpected command: %s", testError, fakeCommandRunner.Cmd)
}
// this isn't 100% foolproof as a bug in a real ContainerCommandRunner where it fails to copy to stdout/stderr wouldn't be caught by this test
if "foobar" != string(actualOutput) {
t.Errorf("(testError=%v) unexpected output %q", testError, actualOutput)
}
if e, a := fmt.Sprintf("%v", testError), fmt.Sprintf("%v", err); e != a {
t.Errorf("(testError=%v) error: expected %s, got %s", testError, e, a)
}
}
}

11
pkg/kubelet/prober/prober.go
View File

@ -223,6 +223,8 @@ func formatURL(scheme string, host string, port int, path string) *url.URL {
}
type execInContainer struct {
// run executes a command in a container. Combined stdout and stderr output is always returned. An
// error is returned if one occurred.
run func() ([]byte, error)
}
@ -231,11 +233,10 @@ func (p *prober) newExecInContainer(container api.Container, containerID kubecon
var buffer bytes.Buffer
output := ioutils.WriteCloserWrapper(&buffer)
err := p.runner.ExecInContainer(containerID, cmd, nil, output, output, false, nil)
if err != nil {
return nil, err
}
return buffer.Bytes(), nil
// Even if err is non-nil, there still may be output (e.g. the exec wrote to stdout or stderr but
// the command returned a nonzero exit code). Therefore, always return the output along with the
// error.
return buffer.Bytes(), err
}}
}

92
pkg/kubelet/prober/prober_test.go
View File

@ -19,6 +19,7 @@ package prober
import (
"errors"
"fmt"
"io"
"net/http"
"reflect"
"testing"
@ -29,6 +30,7 @@ import (
"k8s.io/kubernetes/pkg/kubelet/prober/results"
"k8s.io/kubernetes/pkg/probe"
"k8s.io/kubernetes/pkg/util/intstr"
"k8s.io/kubernetes/pkg/util/term"
)
func TestFormatURL(t *testing.T) {
@ -276,3 +278,93 @@ func TestProbe(t *testing.T) {
}
}
}
type fakeContainerCommandRunner struct {
// what to return
stdoutData string
stderrData string
err error
// actual values when invoked
containerID kubecontainer.ContainerID
cmd []string
stdin io.Reader
tty bool
resize <-chan term.Size
}
var _ kubecontainer.ContainerCommandRunner = &fakeContainerCommandRunner{}
func (f *fakeContainerCommandRunner) ExecInContainer(containerID kubecontainer.ContainerID, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error {
// record invoked values
f.containerID = containerID
f.cmd = cmd
f.stdin = stdin
f.tty = tty
f.resize = resize
fmt.Fprint(stdout, f.stdoutData)
fmt.Fprint(stdout, f.stderrData)
return f.err
}
func (f *fakeContainerCommandRunner) PortForward(pod *kubecontainer.Pod, port uint16, stream io.ReadWriteCloser) error {
panic("not implemented")
}
func TestNewExecInContainer(t *testing.T) {
tests := []struct {
name string
err error
}{
{
name: "no error",
err: nil,
},
{
name: "error - make sure we get output",
err: errors.New("bad"),
},
}
for _, test := range tests {
runner := &fakeContainerCommandRunner{
stdoutData: "foo",
stderrData: "bar",
err: test.err,
}
prober := &prober{
runner: runner,
}
container := api.Container{}
containerID := kubecontainer.ContainerID{Type: "docker", ID: "containerID"}
cmd := []string{"/foo", "bar"}
exec := prober.newExecInContainer(container, containerID, cmd)
actualOutput, err := exec.CombinedOutput()
if e, a := containerID, runner.containerID; e != a {
t.Errorf("%s: container id: expected %v, got %v", test.name, e, a)
}
if e, a := cmd, runner.cmd; !reflect.DeepEqual(e, a) {
t.Errorf("%s: cmd: expected %v, got %v", test.name, e, a)
}
if runner.stdin != nil {
t.Errorf("%s: stdin: expected nil, got %v", test.name, runner.stdin)
}
if runner.tty {
t.Errorf("%s: tty: expected false", test.name)
}
if runner.resize != nil {
t.Errorf("%s: resize chan: expected nil, got %v", test.name, runner.resize)
}
// this isn't 100% foolproof as a bug in a real ContainerCommandRunner where it fails to copy to stdout/stderr wouldn't be caught by this test
if e, a := "foobar", string(actualOutput); e != a {
t.Errorf("%s: output: expected %q, got %q", test.name, e, a)
}
if e, a := fmt.Sprintf("%v", test.err), fmt.Sprintf("%v", err); e != a {
t.Errorf("%s: error: expected %s, got %s", test.name, e, a)
}
}
}