No NgModule metadata found for 'AppModule' Error in Angular 5 server-side rendering with --env.prod - asp.net

Question

I'm trying to upgrade an ASP.NET Core + Angular 4 SPA project from .NET Core 2.0.0/Angular4 to .NET Core 2.0.3/Angular5. I managed to get everything working properly except for the server-side rendering in a production environment, i/e when I publish the app:
An unhandled exception has occurred: No NgModule metadata found for 'AppModule'.
Error: No NgModule metadata found for 'AppModule'.
The issue only happens when both of these two conditions are met:
Webpack builds the packages using the --env.prod switch
The Index.cshtml view file contains the asp-prerender-module parameter, just like in the following example:
<app asp-prerender-module="ClientApp/dist/main-server">Loading...</app>
If I remove the switch and/or the parameter, the problem disappears (together with SSR).
There's a bunch of other info I can give:
It's not something related to IIS, it happens at Kestrel-level.
It's not related to the web server machine because I can even reproduce it with locally by manually launching Webpack with the --end.prod switch right before a Debug or Release run.
It doesn't seem to have anything to do with the source code, as I can reproduce it even with a single-component sample app with very basic AppModule files and trivial code.
The project was running perfectly fine with .NET Core 2.0.0 and Angular 4.3.x.
The only major thing I changed in the webpack.config.js file is replacing the AotPlugin with the new, Angular5-specific AngularCompilerPlugin provided by the #ngtools/webpack package: I think that might as well be the cause, as the --env.prod switch makes use of that AOT compiler instead of the JIT one. That, or something related to the .NET SpaServices package - maybe not on-par with the new Angular5 and/or the new AoT compiler?
Sadly, I can't revert to the former AotPlugin because it throws errors as well - which is perfectly understandable, as it's not meant to be used with Angular5.
Software Versions
.NET Core 2.0.3
Angular 5.0.2
#ngtools/webpack 1.8.2 (also tried with 1.8.1 - same outcome)
WebPack 2.6.1 (also tried with 2.5.6 - same outcome)
webpack.config.js
const path = require('path');
const webpack = require('webpack');
const merge = require('webpack-merge');
const AotPlugin = require('#ngtools/webpack').AngularCompilerPlugin;
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;
module.exports = (env) => {
// Configuration in common to both client-side and server-side bundles
const isDevBuild = !(env && env.prod);
const sharedConfig = {
stats: { modules: false },
context: __dirname,
resolve: { extensions: [ '.js', '.ts' ] },
output: {
filename: '[name].js',
publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
},
module: {
rules: [
{ test: /(?:\.ngfactory\.js|\.ngstyle\.js|\.ts)$/, include: /ClientApp/, use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader'] : '#ngtools/webpack' },
{ test: /\.html$/, use: 'html-loader?minimize=false' },
{ test: /\.css$/, use: [ 'to-string-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize' ] },
{ test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' }
]
},
plugins: [new CheckerPlugin()]
};
// Configuration for client-side bundle suitable for running in browsers
const clientBundleOutputDir = './wwwroot/dist';
const clientBundleConfig = merge(sharedConfig, {
entry: { 'main-client': './ClientApp/boot.browser.ts' },
output: { path: path.join(__dirname, clientBundleOutputDir) },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./wwwroot/dist/vendor-manifest.json')
})
].concat(isDevBuild ? [
// Plugins that apply in development builds only
new webpack.SourceMapDevToolPlugin({
filename: '[file].map', // Remove this line if you prefer inline source maps
moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
})
] : [
// Plugins that apply in production builds only
new webpack.optimize.UglifyJsPlugin(),
new AotPlugin({
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.module.browser#AppModule'),
exclude: ['./**/*.server.ts']
})
])
});
// Configuration for server-side (prerendering) bundle suitable for running in Node
const serverBundleConfig = merge(sharedConfig, {
resolve: { mainFields: ['main'] },
entry: { 'main-server': './ClientApp/boot.server.ts' },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./ClientApp/dist/vendor-manifest.json'),
sourceType: 'commonjs2',
name: './vendor'
})
].concat(isDevBuild ? [] : [
// Plugins that apply in production builds only
new AotPlugin({
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.module.server#AppModule'),
exclude: ['./**/*.browser.ts']
})
]),
output: {
libraryTarget: 'commonjs',
path: path.join(__dirname, './ClientApp/dist')
},
target: 'node',
devtool: 'inline-source-map'
});
return [clientBundleConfig, serverBundleConfig];
};

Answer 1

The #ngtool/webpack configuration for Angular 5 is somewhat different form Angular 2/4. So, I've changed the webpack.config.js as following,
const path = require('path');
const webpack = require('webpack');
const merge = require('webpack-merge');
const AngularCompilerPlugin = require('#ngtools/webpack').AngularCompilerPlugin;
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;
module.exports = (env) => {
// Configuration in common to both client-side and server-side bundles
const isDevBuild = !(env && env.prod);
const sharedConfig = {
stats: { modules: false },
context: __dirname,
resolve: { extensions: [ '.js', '.ts' ] },
output: {
filename: '[name].js',
publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
},
module: {
rules: [
{ test: /\.ts$/, include: /ClientApp/, use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader'] : '#ngtools/webpack' },
{ test: /\.html$/, use: 'html-loader?minimize=false' },
{ test: /\.css$/, use: [ 'to-string-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize' ] },
{ test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' },
{
test: /(?:\.ngfactory\.js|\.ngstyle\.js)$/,
loader: '#ngtools/webpack',
options: {
tsConfigPath: '/tsconfig.json',
}
}
]
},
plugins: [new CheckerPlugin()]
};
// Configuration for client-side bundle suitable for running in browsers
const clientBundleOutputDir = './wwwroot/dist';
const clientBundleConfig = merge(sharedConfig, {
entry: { 'main-client': './ClientApp/boot.browser.ts' },
output: { path: path.join(__dirname, clientBundleOutputDir) },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./wwwroot/dist/vendor-manifest.json')
})
].concat(isDevBuild ? [
// Plugins that apply in development builds only
new webpack.SourceMapDevToolPlugin({
filename: '[file].map', // Remove this line if you prefer inline source maps
moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
})
] : [
// Plugins that apply in production builds only
new webpack.optimize.UglifyJsPlugin(),
new AngularCompilerPlugin({
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.module.browser#AppModule'),
exclude: ['./**/*.server.ts']
})
])
});
// Configuration for server-side (prerendering) bundle suitable for running in Node
const serverBundleConfig = merge(sharedConfig, {
resolve: { mainFields: ['main'] },
entry: { 'main-server': './ClientApp/boot.server.ts' },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./ClientApp/dist/vendor-manifest.json'),
sourceType: 'commonjs2',
name: './vendor'
})
].concat(isDevBuild ? [] : [
// Plugins that apply in production builds only
new AngularCompilerPlugin({
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.module.server#AppModule'),
exclude: ['./**/*.browser.ts']
})
]),
output: {
libraryTarget: 'commonjs',
path: path.join(__dirname, './ClientApp/dist')
},
target: 'node',
devtool: 'inline-source-map'
});
return [clientBundleConfig, serverBundleConfig];
};
And here is my package.json file,
{
"dependencies": {
"#angular/animations": "^5.0.2",
"#angular/cdk": "^5.0.0-rc0",
"#angular/cli": "^1.6.0-beta.2",
"#angular/common": "^5.0.2",
"#angular/compiler": "^5.0.2",
"#angular/compiler-cli": "^5.0.2",
"#angular/core": "^5.0.2",
"#angular/forms": "^5.0.2",
"#angular/http": "^5.0.2",
"#angular/material": "^5.0.0-rc0",
"#angular/platform-browser": "^5.0.2",
"#angular/platform-browser-dynamic": "^5.0.2",
"#angular/platform-server": "^5.0.2",
"#angular/router": "^5.0.2",
"#ngtools/webpack": "^1.8.3",
"#types/webpack-env": "^1.13.2",
"angular2-template-loader": "0.6.2",
"aspnet-prerendering": "^3.0.1",
"aspnet-webpack": "^2.0.1",
"awesome-typescript-loader": "^3.4.0",
"bootstrap": "3.3.7",
"css": "2.2.1",
"css-loader": "^0.28.7",
"es6-shim": "0.35.3",
"event-source-polyfill": "0.0.12",
"expose-loader": "0.7.4",
"extract-text-webpack-plugin": "^3.0.2",
"file-loader": "^1.1.5",
"html-loader": "^0.5.1",
"isomorphic-fetch": "2.2.1",
"jquery": "3.2.1",
"json-loader": "^0.5.7",
"preboot": "^5.1.7",
"raw-loader": "0.5.1",
"reflect-metadata": "0.1.10",
"request": "^2.83.0",
"rxjs": "^5.5.2",
"style-loader": "^0.19.0",
"to-string-loader": "1.1.5",
"typescript": "^2.6.1",
"url-loader": "^0.6.2",
"webpack": "^3.8.1",
"webpack-hot-middleware": "^2.20.0",
"webpack-merge": "^4.1.1",
"zone.js": "^0.8.18"
},
"devDependencies": {
"#types/chai": "^4.0.5",
"#types/jasmine": "^2.8.2",
"#types/node": "^8.0.53",
"chai": "^4.1.2",
"jasmine-core": "2.8.0",
"karma": "1.7.1",
"karma-chai": "0.1.0",
"karma-chrome-launcher": "2.2.0",
"karma-cli": "1.0.1",
"karma-jasmine": "1.1.0",
"karma-webpack": "2.0.6"
},
"name": "aspnetcoreangularspa",
"private": true,
"scripts": {
"test": "karma start ClientApp/test/karma.conf.js"
},
"version": "0.0.0"
}
If you still having problems running the solution, please have a look at this repository for a working solution.
Hope it helps :)

Answer 2

As others suggested, the temporary solution is to remove the SSR (Server Side Rendering). That means opening the Home/Index.cshtml file and change
<app asp-prerender-module="ClientApp/dist/main-server">Loading...</app>
to
<app>Loading...</app>

Answer 3

I found your Issue while searching for a solution to my problem described here:
https://github.com/aspnet/JavaScriptServices/issues/1388
So i tried your webpack-config and also tried to run the app from the repository, but when i do "dotnet publish" and then run the app i get this error:
Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[0]
An unhandled exception has occurred: No NgModule metadata found for 'AppModule'.
Error: No NgModule metadata found for 'AppModule'.
at NgModuleResolver.module.exports.NgModuleResolver.resolve

Answer 4

solution from mak0t0san working for me and ssr still working (angular 5.2.0),
update ngtoolwebpack to 1.10.2
typescript 2.6.2
and change webpack.config.js with that
const path = require('path');
const webpack = require('webpack');
const { DllReferencePlugin, SourceMapDevToolPlugin} = require('webpack');
const merge = require('webpack-merge');
const {AngularCompilerPlugin, PLATFORM} = require('#ngtools/webpack');
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
module.exports = (env) => {
// Configuration in common to both client-side and server-side bundles
const isDevBuild = !(env && env.prod);
const sharedConfig = {
stats: {modules: false},
context: __dirname,
resolve: {extensions: ['.js', '.ts']},
output: {
filename: '[name].js',
chunkFilename:'[id].chunk.js',
publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
},
module: {
rules: [
{test: /\.html$/, use: 'html-loader?minimize=false'},
{test: /\.css$/, use: ['to-string-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize']},
{test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000'},
{
test: /\.(scss)$/,
use: [{
loader: 'style-loader', // inject CSS to page
}, {
loader: 'css-loader', // translates CSS into CommonJS modules
}, {
loader: 'postcss-loader', // Run post css actions
options: {
plugins: function () { // post css plugins, can be exported to postcss.config.js
return [
require('precss'),
require('autoprefixer')
];
}
}
}, {
loader: 'sass-loader' // compiles Sass to CSS
}]
}
]
},
plugins: [new CheckerPlugin()]
};
// Configuration for client-side bundle suitable for running in browsers
const clientBundleOutputDir = './wwwroot/dist';
const clientBundleConfig = merge(sharedConfig, {
module:{
rules:[
{
test: /\.ts$/,
use: ['#ngtools/webpack']
},
]
},
entry: {'main-client': './ClientApp/boot.browser.ts'},
output: {path: path.join(__dirname, clientBundleOutputDir)},
plugins: [
new DllReferencePlugin({
context: __dirname,
manifest: require('./wwwroot/dist/vendor-manifest.json')
}),
new AngularCompilerPlugin({
"mainPath": path.join(__dirname, 'ClientApp/boot.browser.ts'),
platform: PLATFORM.Browser,
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.browser.module#AppModule'),
sourceMap: true
})
].concat(isDevBuild ? [
// Plugins that apply in development builds only
new SourceMapDevToolPlugin({
filename: '[file].map', // Remove this line if you prefer inline source maps
moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
})
] : [
// Plugins that apply in production builds only
new UglifyJsPlugin({
sourceMap: true
})
])
});
// Configuration for server-side (prerendering) bundle suitable for running in Node
const serverBundleConfig = merge(sharedConfig, {
module:{
rules:[
{ test: /\.ts$/, use: ['awesome-typescript-loader?silent=true', 'angular2-template-loader', 'angular2-router-loader'] },
]
},
resolve: { mainFields: ['main'] },
entry: { 'main-server': './ClientApp/boot.server.ts' },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./ClientApp/dist/vendor-manifest.json'),
sourceType: 'commonjs2',
name: './vendor'
})
],
output: {
libraryTarget: 'commonjs',
path: path.join(__dirname, './ClientApp/dist')
},
target: 'node',
devtool: 'inline-source-map'
});
return [clientBundleConfig, serverBundleConfig];
};

Answer 5

As written at the #MMiebach's link:
Angular 5 includes breaking changes (versus Angular 4) meaning that the code for server-side rendering has to be very different.
Luckily, Microsoft released their new SPA project template for Angular 5. It can be installed with
dotnet new --install Microsoft.DotNet.Web.Spa.ProjectTemplates::2.0.0
After that command dotnet new angular will use the 5th Angular instead of 4th.
By default, server-side rendering is not turned on, but there are instructions how to do it in Docs by MS.