fix(cli): ensure that the support bundle command does not panic on zero values (#14392)

We try to write a cute little summary at the end of the bundle, but that could panic if some of the fields of the bundle were nil. Adds a test that essentially ensures nil values in a bundle, and ensures that it can be handled without losing our towels.

Co-authored-by: Danny Kopping <danny@coder.com>

cli/support.go

@@ -184,16 +184,8 @@ func (r *RootCmd) supportBundle() *serpent.Command {
 				_ = os.Remove(outputPath) // best effort
 				return xerrors.Errorf("create support bundle: %w", err)
 			}
-			docsURL := bun.Deployment.Config.Values.DocsURL.String()
-			deployHealthSummary := bun.Deployment.HealthReport.Summarize(docsURL)
-			if len(deployHealthSummary) > 0 {
-				cliui.Warn(inv.Stdout, "Deployment health issues detected:", deployHealthSummary...)
-			}
-			clientNetcheckSummary := bun.Network.Netcheck.Summarize("Client netcheck:", docsURL)
-			if len(clientNetcheckSummary) > 0 {
-				cliui.Warn(inv.Stdout, "Networking issues detected:", deployHealthSummary...)
-			}
 
+			summarizeBundle(inv, bun)
 			bun.CLILogs = cliLogBuf.Bytes()
 
 			if err := writeBundle(bun, zwr); err != nil {
@@ -225,6 +217,40 @@ func (r *RootCmd) supportBundle() *serpent.Command {
 	return cmd
 }
 
+// summarizeBundle makes a best-effort attempt to write a short summary
+// of the support bundle to the user's terminal.
+func summarizeBundle(inv *serpent.Invocation, bun *support.Bundle) {
+	if bun == nil {
+		cliui.Error(inv.Stdout, "No support bundle generated!")
+		return
+	}
+
+	if bun.Deployment.Config == nil {
+		cliui.Error(inv.Stdout, "No deployment configuration available!")
+		return
+	}
+
+	docsURL := bun.Deployment.Config.Values.DocsURL.String()
+	if bun.Deployment.HealthReport == nil {
+		cliui.Error(inv.Stdout, "No deployment health report available!")
+		return
+	}
+	deployHealthSummary := bun.Deployment.HealthReport.Summarize(docsURL)
+	if len(deployHealthSummary) > 0 {
+		cliui.Warn(inv.Stdout, "Deployment health issues detected:", deployHealthSummary...)
+	}
+
+	if bun.Network.Netcheck == nil {
+		cliui.Error(inv.Stdout, "No network troubleshooting information available!")
+		return
+	}
+
+	clientNetcheckSummary := bun.Network.Netcheck.Summarize("Client netcheck:", docsURL)
+	if len(clientNetcheckSummary) > 0 {
+		cliui.Warn(inv.Stdout, "Networking issues detected:", deployHealthSummary...)
+	}
+}
+
 func findAgent(agentName string, haystack []codersdk.WorkspaceResource) (*codersdk.WorkspaceAgent, bool) {
 	for _, res := range haystack {
 		for _, agt := range res.Agents {

cli/support_test.go

@@ -5,6 +5,9 @@ import (
 	"bytes"
 	"encoding/json"
 	"io"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -14,6 +17,7 @@ import (
 	"tailscale.com/ipn/ipnstate"
 
 	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"github.com/coder/coder/v2/agent"
@@ -156,6 +160,53 @@ func TestSupportBundle(t *testing.T) {
 		err := inv.Run()
 		require.ErrorContains(t, err, "failed authorization check")
 	})
+
+	// This ensures that the CLI does not panic when trying to generate a support bundle
+	// against a fake server that returns an empty response for all requests. This essentially
+	// ensures that (almost) all of the support bundle generating code paths get a zero value.
+	t.Run("DontPanic", func(t *testing.T) {
+		t.Parallel()
+
+		for _, code := range []int{
+			http.StatusOK,
+			http.StatusUnauthorized,
+			http.StatusForbidden,
+			http.StatusNotFound,
+			http.StatusInternalServerError,
+		} {
+			t.Run(http.StatusText(code), func(t *testing.T) {
+				t.Parallel()
+				// Start up a fake server
+				srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					t.Logf("received request: %s %s", r.Method, r.URL)
+					switch r.URL.Path {
+					case "/api/v2/authcheck":
+						// Fake auth check
+						resp := codersdk.AuthorizationResponse{
+							"Read DeploymentValues": true,
+						}
+						w.WriteHeader(http.StatusOK)
+						assert.NoError(t, json.NewEncoder(w).Encode(resp))
+					default:
+						// Simply return a blank response for everything else.
+						w.WriteHeader(code)
+					}
+				}))
+				defer srv.Close()
+				u, err := url.Parse(srv.URL)
+				require.NoError(t, err)
+				client := codersdk.New(u)
+
+				d := t.TempDir()
+				path := filepath.Join(d, "bundle.zip")
+
+				inv, root := clitest.New(t, "support", "bundle", "--url-override", srv.URL, "--output-file", path, "--yes")
+				clitest.SetupConfig(t, client, root)
+				err = inv.Run()
+				require.NoError(t, err)
+			})
+		}
+	})
 }
 
 // nolint:revive // It's a control flag, but this is just a test.