openshift-diagnostics: package as oc alias

Makes `openshift-diagnostics` a symlink to `oc` (like `kubectl`) so that
it can be packaged inside origin pods to be run from diagnostics.

fixes openshift#18141

hack/lib/constants.sh

@@ -43,7 +43,6 @@ readonly OS_CROSS_COMPILE_TARGETS=(
   cmd/openshift
   cmd/oc
   cmd/oadm
-  cmd/openshift-diagnostics
   cmd/template-service-broker
   vendor/k8s.io/kubernetes/cmd/hyperkube
 )
@@ -75,6 +74,7 @@ readonly OPENSHIFT_BINARY_SYMLINKS=(
 )
 readonly OC_BINARY_COPY=(
   kubectl
+  openshift-diagnostics
 )
 readonly OS_BINARY_RELEASE_CLIENT_WINDOWS=(
   oc.exe

origin.spec

@@ -331,6 +331,7 @@ do
 done
 
 ln -s oc %{buildroot}%{_bindir}/kubectl
+ln -s oc %{buildroot}%{_bindir}/openshift-diagnostics
 
 install -d -m 0755 %{buildroot}%{_sysconfdir}/origin/{master,node}
 
@@ -533,6 +534,7 @@ fi
 %license LICENSE
 %{_bindir}/oc
 %{_bindir}/kubectl
+%{_bindir}/openshift-diagnostics
 %{_bindir}/oadm
 %{_sysconfdir}/bash_completion.d/oc
 %{_mandir}/man1/oc*

pkg/oc/admin/diagnostics/inpod.go

@@ -0,0 +1,26 @@
+package diagnostics
+
+import (
+	"io"
+
+	"github.com/spf13/cobra"
+)
+
+const (
+	DiagnosticsInPodRecommendedName = "openshift-diagnostics"
+)
+
+// NewCmdDiagnosticsInPod defines the base command that is used inside of a pod
+// orchestrated by a regular diagnostic, to report from the in-pod vantage point.
+func NewCmdDiagnosticsInPod(name string, fullName string, out io.Writer) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   name,
+		Short: "Diagnose OpenShift from inside a pod",
+	}
+	cmd.AddCommand(
+		NewCommandPodDiagnostics("diagnostic-pod", out),
+		NewCommandNetworkPodDiagnostics("network-diagnostic-pod", out),
+	)
+
+	return cmd
+}

pkg/oc/cli/cli.go

@@ -312,6 +312,8 @@ func CommandFor(basename string) *cobra.Command {
 	switch basename {
 	case "kubectl":
 		cmd = kubecmd.NewKubectlCommand(kcmdutil.NewFactory(nil), in, out, errout)
+	case diagnostics.DiagnosticsInPodRecommendedName:
+		cmd = diagnostics.NewCmdDiagnosticsInPod(basename, basename, out)
 	default:
 		cmd = NewCommandCLI("oc", "oc", in, out, errout)
 	}