Add a timeout of 1s to the 'podman version' command

This command is called at dependency injection time to initialize a (nil-able) Podman client,
even if users won't use Podman at all.
As discussed, this command is supposed to be
quite fast to return, hence this timeout of 1 second.

Initially, we were using cmd.Output to get the command output,
but as reported in [1], cmd.Output does not respect the context timeout.
This explains the workaround of reading from both stdout and stderr pipes,
*and* relying on cmd.Wait() to close those pipes properly when the program exits
(either as expected or when the timeout is reached).

[1] golang/go#57129

Co-authored-by: Philippe Martin <[email protected]>

Author: rm3l

pkg/podman/interface.go

@@ -1,6 +1,8 @@
 package podman
 
 import (
+	"context"
+
 	corev1 "k8s.io/api/core/v1"
 
 	"github.com/redhat-developer/odo/pkg/api"
@@ -36,5 +38,5 @@ type Client interface {
 
 	ListAllComponents() ([]api.ComponentAbstract, error)
 
-	Version() (SystemVersionReport, error)
+	Version(ctx context.Context) (SystemVersionReport, error)
 }

pkg/podman/mock.go

@@ -33,7 +33,7 @@ func NewPodmanCli(ctx context.Context) (*PodmanCli, error) {
 		containerRunGlobalExtraArgs: envcontext.GetEnvConfig(ctx).OdoContainerBackendGlobalArgs,
 		containerRunExtraArgs:       envcontext.GetEnvConfig(ctx).OdoContainerRunArgs,
 	}
-	version, err := cli.Version()
+	version, err := cli.Version(ctx)
 	if err != nil {
 		return nil, err
 	}

pkg/podman/podman.go

@@ -1,9 +1,13 @@
 package podman
 
 import (
+	"bytes"
+	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"os/exec"
+	"time"
 
 	"k8s.io/klog"
 )
@@ -23,20 +27,78 @@ type SystemVersionReport struct {
 	Client *Version `json:",omitempty"`
 }
 
-func (o *PodmanCli) Version() (SystemVersionReport, error) {
-	cmd := exec.Command(o.podmanCmd, "version", "--format", "json")
+// Version returns the version of the Podman client.
+func (o *PodmanCli) Version(ctx context.Context) (SystemVersionReport, error) {
+	// Because Version is used at the very beginning of odo, when resolving and injecting dependencies (for commands that might require the Podman client),
+	// it is expected to return in a timely manny (hence this timeout of 1 second).
+	// This is to avoid situations like the one described in https://github.com/redhat-developer/odo/issues/6575
+	// (where a podman that takes too long to respond affects the "odo dev" command, even if the user did not intend to use the Podman platform).
+	ctxWithTimeout, cancel := context.WithTimeout(ctx, 1*time.Second)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctxWithTimeout, o.podmanCmd, "version", "--format", "json")
 	klog.V(3).Infof("executing %v", cmd.Args)
-	out, err := cmd.Output()
+
+	// Because cmd.Output() does not respect the context timeout (see https://github.com/golang/go/issues/57129),
+	// we are reading from the connected pipes instead.
+	stdoutPipe, err := cmd.StdoutPipe()
 	if err != nil {
-		if exiterr, ok := err.(*exec.ExitError); ok {
-			err = fmt.Errorf("%s: %s", err, string(exiterr.Stderr))
-		}
 		return SystemVersionReport{}, err
 	}
-	var result SystemVersionReport
-	err = json.Unmarshal(out, &result)
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		return SystemVersionReport{}, err
+	}
+
+	err = cmd.Start()
 	if err != nil {
 		return SystemVersionReport{}, err
 	}
+
+	var result SystemVersionReport
+	go func() {
+		// Reading from the pipe is a blocking call, hence this goroutine.
+		// The goroutine will exit after the pipe is closed or the command exits;
+		// these will be triggered by cmd.Wait() either after the timeout expires or the command finished.
+		err = json.NewDecoder(stdoutPipe).Decode(&result)
+		if err != nil {
+			klog.V(3).Infof("unable to decode output: %v", err)
+		}
+	}()
+
+	var stderr string
+	go func() {
+		var buf bytes.Buffer
+		_, rErr := buf.ReadFrom(stderrPipe)
+		if rErr != nil {
+			klog.V(7).Infof("unable to read from stderr pipe: %v", rErr)
+		}
+		stderr = buf.String()
+	}()
+
+	// Wait will block until the timeout expires or the command exits. It will then close all resources associated with cmd,
+	// including the stdout and stderr pipes above, which will in turn terminate the goroutines spawned above.
+	wErr := cmd.Wait()
+	if wErr != nil {
+		ctxErr := ctxWithTimeout.Err()
+		if ctxErr != nil {
+			msg := "error"
+			if errors.Is(ctxErr, context.DeadlineExceeded) {
+				msg = "timeout"
+			}
+			wErr = fmt.Errorf("%s while waiting for Podman version: %s: %w", msg, ctxErr, wErr)
+		}
+		if exitErr, ok := wErr.(*exec.ExitError); ok {
+			wErr = fmt.Errorf("%s: %s", wErr, string(exitErr.Stderr))
+		}
+		if err != nil {
+			wErr = fmt.Errorf("%s: (%w)", wErr, err)
+		}
+		if stderr != "" {
+			wErr = fmt.Errorf("%w: %s", wErr, stderr)
+		}
+		return SystemVersionReport{}, fmt.Errorf("%v. Please check the output of the following command: %v", wErr, cmd.Args)
+	}
+
 	return result, nil
 }

pkg/podman/version.go

@@ -150,7 +150,7 @@ func setPlatformCluster(ctx context.Context, client kclient.ClientInterface) {
 
 func setPlatformPodman(ctx context.Context, client podman.Client) {
 	setContextProperty(ctx, Platform, "podman")
-	version, err := client.Version()
+	version, err := client.Version(ctx)
 	if err != nil {
 		klog.V(3).Info(fmt.Errorf("unable to get podman version: %w", err))
 		return