Fail integration test early when a plugin load fails

Avoid running tests when a plugin fails to load and return the init
error from the plugin. This prevents the test failing later with an
unhelpful error and attempting to find the actual error in the daemon
logs.

Signed-off-by: Derek McGowan <derek@mcg.dev>

integration/client/daemon.go

@@ -23,10 +23,13 @@ import (
 	"io"
 	"os/exec"
 	"runtime"
+	"strings"
 	"sync"
 	"syscall"
 	"time"
 
+	"github.com/containerd/plugin"
+
 	. "github.com/containerd/containerd/v2/client"
 )
 
@@ -79,6 +82,21 @@ func (d *daemon) waitForStart(ctx context.Context) (*Client, error) {
 				}
 				continue
 			}
+			resp, perr := client.IntrospectionService().Plugins(ctx)
+			if perr != nil {
+				return nil, fmt.Errorf("failed to get plugin list: %w", perr)
+			}
+			var loadErr error
+			for _, p := range resp.Plugins {
+				if p.InitErr != nil && !strings.Contains(p.InitErr.Message, plugin.ErrSkipPlugin.Error()) {
+					pluginErr := fmt.Errorf("failed to load %s.%s: %s", p.Type, p.ID, p.InitErr.Message)
+					loadErr = errors.Join(loadErr, pluginErr)
+				}
+			}
+			if loadErr != nil {
+				return nil, loadErr
+			}
+
 			return client, err
 		case <-ctx.Done():
 			return nil, fmt.Errorf("context deadline exceeded: %w", err)