Fix: vela show panic for component markdown format

Signed-off-by: qiaozp <qiaozhongpei.qzp@alibaba-inc.com>

e2e/commonContext.go

@@ -186,4 +186,14 @@ var (
 			})
 		})
 	}
+
+	ShowCapabilityReferenceMarkdown = func(context string, capabilityName string) bool {
+		return ginkgo.Context(context, func() {
+			ginkgo.It("should show capability reference in markdown", func() {
+				cli := fmt.Sprintf("vela show %s --format=markdown", capabilityName)
+				_, err := Exec(cli)
+				gomega.Expect(err).Should(gomega.BeNil())
+			})
+		})
+	}
 )

e2e/trait/trait_test.go

@@ -28,6 +28,7 @@ var _ = ginkgo.Describe("Trait", func() {
 
 var _ = ginkgo.Describe("Test vela show", func() {
 	e2e.ShowCapabilityReference("show ingress", "ingress")
+	e2e.ShowCapabilityReferenceMarkdown("show ingress markdown", "ingress")
 
 	env := "namespace-xxxfwrr23erfm"
 	e2e.EnvInitWithNamespaceOptionContext("env init", env, env)

e2e/workload/workload_test.go

@@ -37,6 +37,7 @@ var _ = Describe("Workload", func() {
 
 var _ = Describe("Test vela show", func() {
 	e2e.ShowCapabilityReference("show webservice", "webservice")
+	e2e.ShowCapabilityReferenceMarkdown("show webservice markdown", "webservice")
 
 	env := "namespace-xxxfwrr23erfm"
 	e2e.EnvInitWithNamespaceOptionContext("env init", env, env)

references/cli/show.go

@@ -186,6 +186,10 @@ func startReferenceDocsSite(ctx context.Context, ns string, c common.Args, ioStr
 	if err != nil {
 		return err
 	}
+	ref.DiscoveryMapper, err = c.GetDiscoveryMapper()
+	if err != nil {
+		return err
+	}
 	if err := ref.CreateMarkdown(ctx, capabilities, docsPath, true, pd); err != nil {
 		return err
 	}
@@ -454,6 +458,10 @@ func ShowReferenceMarkdown(ctx context.Context, c common.Args, ioStreams cmdutil
 		return err
 	}
 	ref.ParseReference = paserRef
+	ref.DiscoveryMapper, err = c.GetDiscoveryMapper()
+	if err != nil {
+		return err
+	}
 	if err := ref.GenerateReferenceDocs(ctx, c, outputPath); err != nil {
 		return errors.Wrap(err, "failed to generate reference docs")
 	}