test: Ensure that BTF type information is available

BTF types are required for CO-RE eBPF programs. Check if the kernel was compiled
with CONFIG_DEBUG_INFO_BTF and created the /sys/kernel/btf/vmlinux file.

Author: blu3r4y

test/integration/iso_test.go

@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"os/exec"
 	"runtime"
+	"strings"
 	"testing"
 
 	"k8s.io/minikube/pkg/minikube/vmpath"
@@ -99,4 +100,17 @@ func TestISOImage(t *testing.T) {
 			})
 		}
 	})
+
+	t.Run("eBPFSupport", func(t *testing.T) {
+		// Ensure that BTF type information is available (https://github.com/kubernetes/minikube/issues/21788)
+		btfFile := "/sys/kernel/btf/vmlinux"
+		rr, err := Run(t, exec.CommandContext(ctx, Target(), "-p", profile, "ssh", fmt.Sprintf("test -f %s && echo 'OK' || echo 'NOT FOUND'", btfFile)))
+		if err != nil {
+			t.Errorf("failed to verify existence of %q file: args %q: %v", btfFile, rr.Command(), err)
+		}
+
+		if !strings.Contains(rr.Stdout.String(), "OK") {
+			t.Errorf("expected file %q to exist, but it does not. BTF types are required for CO-RE eBPF programs; set CONFIG_DEBUG_INFO_BTF in kernel configuration.", btfFile)
+		}
+	})
 }