feat: handle template build error

internal/apierror/api_error.go

@@ -0,0 +1,17 @@
+package apierror
+
+import "fmt"
+
+type APIError struct {
+	StatusCode int    `json:"-"`
+	Code       string `json:"code"`
+	Message    string `json:"error"`
+}
+
+func New(status int, code, message string) *APIError {
+	return &APIError{status, code, message}
+}
+
+func (err *APIError) Error() string {
+	return fmt.Sprintf("%s: %s", err.Code, err.Message)
+}

internal/template/errors.go

@@ -0,0 +1,9 @@
+package template
+
+type errBadTemplate struct {
+	message string
+}
+
+func (err *errBadTemplate) Error() string {
+	return err.message
+}

internal/template/http_handlers.go

@@ -7,6 +7,7 @@ import (
 	"github.com/labstack/echo/v4"
 	"io"
 	"net/http"
+	"tesseract/internal/apierror"
 	"tesseract/internal/service"
 )
 
@@ -136,6 +137,10 @@ func buildTemplate(c echo.Context, body postTemplateRequestBody) error {
 		buildArgs: body.BuildArgs,
 	})
 	if err != nil {
+		var errBadTemplate *errBadTemplate
+		if errors.As(err, &errBadTemplate) {
+			return apierror.New(http.StatusBadRequest, "BAD_TEMPLATE", errBadTemplate.message)
+		}
 		return err
 	}
 

internal/template/template_manager.go

@@ -11,8 +11,10 @@ import (
 	"fmt"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
+	"github.com/docker/docker/errdefs"
 	"github.com/google/uuid"
 	"github.com/uptrace/bun"
+	"strings"
 	"time"
 )
 
@@ -252,6 +254,14 @@ func (mgr *templateManager) buildTemplate(ctx context.Context, template *templat
 		BuildArgs: opts.buildArgs,
 	})
 	if err != nil {
+		if errdefs.IsInvalidParameter(err) {
+			return nil, &errBadTemplate{
+				// the docker sdk returns an error message that looks like:
+				// "Error response from daemon: dockerfile parse error on line 1: unknown instruction: FR (did you mean FROM?)"
+				// we don't want the "error response..." part because it is meaningless
+				message: strings.Replace(err.Error(), "Error response from daemon: ", "", 1),
+			}
+		}
 		return nil, err
 	}
 

main.go

@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"tesseract/internal/apierror"
 	"tesseract/internal/migration"
 	"tesseract/internal/service"
 	"tesseract/internal/template"
@@ -86,10 +87,20 @@ func main() {
 				c.Logger().Error(err)
 				_ = c.NoContent(http.StatusInternalServerError)
 			}
-		} else {
+			return
-			c.Logger().Error(err)
-			_ = c.NoContent(http.StatusInternalServerError)
 		}
+
+		var apiErr *apierror.APIError
+		if errors.As(err, &apiErr) {
+			if err = c.JSON(apiErr.StatusCode, apiErr); err != nil {
+				c.Logger().Error(err)
+				_ = c.NoContent(http.StatusInternalServerError)
+			}
+			return
+		}
+
+		c.Logger().Error(err)
+		_ = c.NoContent(http.StatusInternalServerError)
 	}
 
 	apiServer.Logger.Fatal(apiServer.Start(":8080"))

web/src/api.ts

@@ -1,5 +1,12 @@
 import { promiseOrThrow } from "./lib/errors";
 
+interface ApiErrorResponse {
+	code: string;
+	error: string;
+}
+
+const API_ERROR_BAD_TEMPLATE = "BAD_TEMPLATE";
+
 enum ApiError {
 	NotFound = "NOT_FOUND",
 	BadRequest = "BAD_REQUEST",
@@ -16,10 +23,9 @@ async function fetchApi(
 		() => ApiError.Network,
 	);
 	if (res.status !== 200) {
-		console.log(res.status);
 		switch (res.status) {
-			case 401:
+			case 400:
-				throw ApiError.BadRequest;
+				throw await res.json();
 			case 404:
 				throw ApiError.NotFound;
 			default:
@@ -29,4 +35,15 @@ async function fetchApi(
 	return res;
 }
 
-export { ApiError, fetchApi };
+function isApiErrorResponse(error: unknown): error is ApiErrorResponse {
+	return (
+		error !== null &&
+		error !== undefined &&
+		typeof error === "object" &&
+		"code" in error &&
+		"error" in error
+	);
+}
+
+export { API_ERROR_BAD_TEMPLATE, ApiError, fetchApi, isApiErrorResponse };
+export type { ApiErrorResponse };

web/src/templates/api.ts

@@ -144,6 +144,10 @@ async function buildTemplate({
 			Accept: "text/event-stream",
 		},
 	});
+	if (res.status !== 200) {
+		const errBody = await res.json();
+		throw errBody;
+	}
 	const stream = res.body?.pipeThrough(new TextDecoderStream()).getReader();
 	if (stream) {
 		while (true) {

web/src/templates/template-editor-store.tsx

@@ -2,6 +2,7 @@ import { createStore, useStore } from "zustand";
 import type { Template } from "./types";
 import { createContext, useContext } from "react";
 import { buildTemplate } from "./api";
+import { isApiErrorResponse, type ApiErrorResponse } from "@/api";
 
 interface TemplateEditorState {
 	template: Template;
@@ -9,6 +10,7 @@ interface TemplateEditorState {
 	isBuildInProgress: boolean;
 	isBuildOutputVisible: boolean;
 	buildOutput: string;
+	buildError: ApiErrorResponse | null;
 
 	startBuild: ({
 		imageTag,
@@ -34,6 +36,7 @@ function createTemplateEditorStore({
 		isBuildInProgress: false,
 		isBuildOutputVisible: false,
 		buildOutput: "",
+		buildError: null,
 
 		startBuild: async ({ imageTag, buildArgs }) => {
 			const state = get();
@@ -42,6 +45,7 @@ function createTemplateEditorStore({
 				isBuildInProgress: true,
 				isBuildOutputVisible: true,
 				buildOutput: "",
+				buildError: null,
 			});
 
 			try {
@@ -51,8 +55,12 @@ function createTemplateEditorStore({
 					templateName: state.template.name,
 					onBuildOutput: state.addBuildOutputChunk,
 				});
-			} catch {
+			} catch (error) {
-				// TODO: handle build error
+				console.error(error);
+				if (isApiErrorResponse(error)) {
+					console.log("askdjskdjk");
+					set({ buildError: error });
+				}
 			} finally {
 				set({ isBuildInProgress: false });
 			}

web/src/templates/template-editor.tsx

@@ -1,4 +1,4 @@
-import { ApiError } from "@/api";
+import { API_ERROR_BAD_TEMPLATE, ApiError } from "@/api";
 import { CodeMirrorEditor } from "@/components/codemirror-editor";
 import { Button } from "@/components/ui/button.tsx";
 import { Dialog, DialogTrigger } from "@/components/ui/dialog";
@@ -35,7 +35,7 @@ import {
 } from "./template-editor-store";
 import type { Template } from "./types";
 import { useToast } from "@/hooks/use-toast";
-import { ToastAction } from "@/components/ui/toast";
+import { Toaster } from "@/components/ui/toaster";
 
 function TemplateEditor() {
 	const { templateName, _splat } = templateEditorRoute.useParams();
@@ -122,6 +122,8 @@ function _TemplateEditor({
 						<TemplateBuildOutputPanel />
 					</main>
 				</div>
+				<Toaster />
+				<BuildErrorToast />
 			</SidebarProvider>
 		</TemplateEditorStoreContext.Provider>
 	);
@@ -332,4 +334,33 @@ function BuildOutput() {
 	);
 }
 
+function BuildErrorToast() {
+	const buildError = useTemplateEditorStore((state) => state.buildError);
+	const { toast } = useToast();
+
+	useEffect(() => {
+		if (!buildError) return;
+
+		switch (buildError.code) {
+			case API_ERROR_BAD_TEMPLATE:
+				toast({
+					variant: "destructive",
+					title: "Invalid template",
+					description: buildError.error,
+				});
+				break;
+
+			default:
+				toast({
+					variant: "destructive",
+					title: "Unexpected error",
+					description: buildError.error,
+				});
+				break;
+		}
+	}, [buildError, toast]);
+
+	return false;
+}
+
 export { TemplateEditor };