fix: reduce excessive logging when database is unreachable (#17363)

Fixes #17045

---------

Signed-off-by: Danny Kopping <dannykopping@gmail.com>

codersdk/database.go

@@ -0,0 +1,7 @@
+package codersdk
+
+import "golang.org/x/xerrors"
+
+const DatabaseNotReachable = "database not reachable"
+
+var ErrDatabaseNotReachable = xerrors.New(DatabaseNotReachable)

codersdk/workspacesdk/dialer.go

@@ -11,17 +11,19 @@ import (
 	"golang.org/x/xerrors"
 
 	"cdr.dev/slog"
+	"github.com/coder/websocket"
+
 	"github.com/coder/coder/v2/buildinfo"
 	"github.com/coder/coder/v2/codersdk"
 	"github.com/coder/coder/v2/tailnet"
 	"github.com/coder/coder/v2/tailnet/proto"
-	"github.com/coder/websocket"
 )
 
 var permanentErrorStatuses = []int{
-	http.StatusConflict,   // returned if client/agent connections disabled (browser only)
-	http.StatusBadRequest, // returned if API mismatch
-	http.StatusNotFound,   // returned if user doesn't have permission or agent doesn't exist
+	http.StatusConflict,            // returned if client/agent connections disabled (browser only)
+	http.StatusBadRequest,          // returned if API mismatch
+	http.StatusNotFound,            // returned if user doesn't have permission or agent doesn't exist
+	http.StatusInternalServerError, // returned if database is not reachable,
 }
 
 type WebsocketDialer struct {
@@ -89,6 +91,11 @@ func (w *WebsocketDialer) Dial(ctx context.Context, r tailnet.ResumeTokenControl
 						"Ensure your client release version (%s, different than the API version) matches the server release version",
 						buildinfo.Version())
 				}
+
+				if sdkErr.Message == codersdk.DatabaseNotReachable &&
+					sdkErr.StatusCode() == http.StatusInternalServerError {
+					err = xerrors.Errorf("%w: %v", codersdk.ErrDatabaseNotReachable, err)
+				}
 			}
 			w.connected <- err
 			return tailnet.ControlProtocolClients{}, err

codersdk/workspacesdk/workspacesdk_test.go

@@ -1,13 +1,21 @@
 package workspacesdk_test
 
 import (
+	"net/http"
+	"net/http/httptest"
 	"net/url"
 	"testing"
 
 	"github.com/stretchr/testify/require"
 	"tailscale.com/tailcfg"
 
+	"github.com/coder/websocket"
+
+	"github.com/coder/coder/v2/coderd/httpapi"
+	"github.com/coder/coder/v2/codersdk"
 	"github.com/coder/coder/v2/codersdk/agentsdk"
+	"github.com/coder/coder/v2/codersdk/workspacesdk"
+	"github.com/coder/coder/v2/testutil"
 )
 
 func TestWorkspaceRewriteDERPMap(t *testing.T) {
@@ -37,3 +45,30 @@ func TestWorkspaceRewriteDERPMap(t *testing.T) {
 	require.Equal(t, "coconuts.org", node.HostName)
 	require.Equal(t, 44558, node.DERPPort)
 }
+
+func TestWorkspaceDialerFailure(t *testing.T) {
+	t.Parallel()
+
+	// Setup.
+	ctx := testutil.Context(t, testutil.WaitShort)
+	logger := testutil.Logger(t)
+
+	// Given: a mock HTTP server which mimicks an unreachable database when calling the coordination endpoint.
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		httpapi.Write(ctx, w, http.StatusInternalServerError, codersdk.Response{
+			Message: codersdk.DatabaseNotReachable,
+			Detail:  "oops",
+		})
+	}))
+	t.Cleanup(srv.Close)
+
+	u, err := url.Parse(srv.URL)
+	require.NoError(t, err)
+
+	// When: calling the coordination endpoint.
+	dialer := workspacesdk.NewWebsocketDialer(logger, u, &websocket.DialOptions{})
+	_, err = dialer.Dial(ctx, nil)
+
+	// Then: an error indicating a database issue is returned, to conditionalize the behavior of the caller.
+	require.ErrorIs(t, err, codersdk.ErrDatabaseNotReachable)
+}