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Deployment

部署

This page describes techniques for deploying your Angular application to a remote server.

本章会描述在远程服务器上部署 Angular 应用的工具与技术。

Simplest deployment possible

最简化的部署方式

For the simplest deployment, build for development and copy the output directory to a web server.

最简化的部署方式就是为开发环境构建，并把其输出复制到 Web 服务器上。

  1. Start with the development build

    使用开发环境进行构建

    ng build

  2. Copy everything within the output folder (dist/ by default) to a folder on the server.

    把输出目录（默认为 dist/）下的每个文件都复制到到服务器上的某个目录下。

  3. If you copy the files into a server sub-folder, append the build flag, --base-href and set the <base href> appropriately.

    如果要把文件部署到服务器上的某个子路径下，构建时还要添加 --base-href（基地址）标识，并设置合适的 <base href>。

    For example, if the index.html is on the server at /my/app/index.html, set the base href to <base href="/my/app/"> like this.

    比如，如果 index.html 位于服务器上的 /my/app/index.html 路径下，就要把 base href 设置为 <base href="/my/app/">，就像这样：

    ng build --base-href=/my/app/

    You'll see that the <base href> is set properly in the generated dist/index.html.

    If you copy to the server's root directory, omit this step and leave the <base href> alone.

    Learn more about the role of <base href> below.

    你会看到在生成的 dist/index.html 中 <base href> 已经被设置好了。

    如果复制到服务器的根目录下，就省略这个步骤，并且让 <base href> 保持原样。

    要了解 <base href> 的作用，参见 下面 的内容。

  4. Configure the server to redirect requests for missing files to index.html. Learn more about server-side redirects below.

    配置服务器，使其在找不到文件时把请求重定向到 index.html。要了解服务端重定向的更多知识，参见 下面 的内容。

This is not a production deployment. It's not optimized and it won't be fast for users. It might be good enough for sharing your progress and ideas internally with managers, teammates, and other stakeholders.

这不是生产级部署。它没有优化过，并且对用户来说也不够快。 但是当你向经理、团队成员或其它利益相关者内部分享你的进度和想法时它是足够的。

Optimize for production

为生产环境优化

Although deploying directly from the development environment works, you can generate an optimized build with additional CLI command line flags, starting with --prod.

虽然也可以直接用开发环境的设置进行部署，不过你也可以使用 CLI 命令的其它标志生成一个优化过的构建成果。 先来看 --prod。

Build with --prod

使用 --prod 构建。

ng build --prod

The --prod meta-flag engages the following optimization features.

--prod 元标志包括下列优化特性。

  • Ahead-of-Time (AOT) Compilation: pre-compiles Angular component templates.

    预(AOT)编译：预编译 Angular 组件的模板。

  • Production mode: deploys the production environment which enables production mode.

    生产模式：启用生产模式部署到生产环境。

  • Bundling: concatenates your many application and library files into a few bundles.

    打捆（Bundle）：把这些模块串接成一个单独的捆文件（bundle）。

  • Minification: removes excess whitespace, comments, and optional tokens.

    最小化：移除不必要的空格、注释和可选令牌（Token）。

  • Uglification: rewrites code to use short, cryptic variable and function names.

    混淆：使用短的、无意义的变量名和函数名来重写代码。

  • Dead code elimination: removes unreferenced modules and much unused code.

    消除死代码：移除未引用过的模块和未使用过的代码。

The remaining copy deployment steps are the same as before.

剩下的 拷贝部署步骤 和以前的方式是一样的。

You may further reduce bundle sizes by adding the build-optimizer flag.

你还可以添加 build-optimizer 标志来进一步缩减打包体积。

ng build --prod --build-optimizer

See the CLI Documentation for details about available build options and what they do.

参见 CLI 文档，来了解可用的构建选项及其用途的详细信息。

Enable production mode

启用生产模式

Angular apps run in development mode by default, as you can see by the following message on the browser console:

Angular 应用默认运行在开发模式下，正如在浏览器控制台中看到的如下信息：

Angular is running in the development mode. Call enableProdMode() to enable the production mode.

Switching to production mode can make it run faster by disabling development specific checks such as the dual change detection cycles.

切换到生产模式可以通过禁用开发环境下特有的检查（比如双重变更检测周期）来让应用运行得更快。

Building for production (or appending the --environment=prod flag) enables production mode Look at the CLI-generated main.ts to see how this works.

为生产环境构建（或添加 --environment=prod 标志）可以启用生产模式。 查看 CLI 自动生成的 main.ts 文件来了解它的工作原理。

Lazy loading

惰性加载

You can dramatically reduce launch time by only loading the application modules that absolutely must be present when the app starts.

通过只加载应用启动时必须展示的那些应用模块，你可以显著缩减启动时间。

Configure the Angular Router to defer loading of all other modules (and their associated code), either by waiting until the app has launched or by lazy loading them on demand.

配置 Angular 路由器可以延迟加载所有其它模块（以及与它们相关的代码），无论是等应用启动， 还是在需要时才惰性加载。

Don't eagerly import something from a lazy loaded module

不要立即导入惰性加载模块中的任何东西

It's a common mistake. You've arranged to lazy load a module. But you unintentionally import it, with a JavaScript import statement, in a file that's eagerly loaded when the app starts, a file such as the root AppModule. If you do that, the module will be loaded immediately.

这是一种常犯的错误。 你本打算惰性加载一个模块，但可能无意中在根模块 AppModule 文件中使用一个 JavaScript 的 import 语句导入了它。 这样一来，该模块就被立即加载了。

The bundling configuration must take lazy loading into consideration. Because lazy loaded modules aren't imported in JavaScript (as just noted), bundlers exclude them by default. Bundlers don't know about the router configuration and won't create separate bundles for lazy loaded modules. You have to create these bundles manually.

关于打包（bundle）方式的配置必须考虑到惰性加载问题。 因为惰性加载模块不能在 JavaScript 中导入（就像刚才说明的），打包器应该默认排除它们。 打包器不知道路由器的配置，并且不会为延迟加载模块创建单独的包。 你不得不手动创建这些包。

The CLI runs the Angular Ahead-of-Time Webpack Plugin which automatically recognizes lazy loaded NgModules and creates separate bundles for them.

CLI 会运行 Angular AOT 编译 Webpack 插件，它会自动识别出那些需要惰性加载的 NgModule，并为它们创建单独的文件包。

Measure performance

性能测量

You can make better decisions about what to optimize and how when you have a clear and accurate understanding of what's making the application slow. The cause may not be what you think it is. You can waste a lot of time and money optimizing something that has no tangible benefit or even makes the app slower. You should measure the app's actual behavior when running in the environments that are important to you.

如果你能对“是什么导致了应用变慢”的问题有一个清晰、准确的理解，那就可以对优化什么、如何优化做出更好地决策了。 真正的原因可能并不是你所想的那样。 你可能花费大量的时间和金钱去优化一些东西，但它却无法产生可感知的效果甚至让应用变得更慢。 你应该在那些最重要的环境中实际运行，来度量应用的实际行为。

The Chrome DevTools Network Performance page is a good place to start learning about measuring performance.

Chrome 开发工具的网络性能页是开始学习度量性能的好地方。

The WebPageTest tool is another good choice that can also help verify that your deployment was successful.

WebPageTest工具是另一个不错的选择，它能帮你验证你的部署是否成功了。

Inspect the bundles

深入探查文件包（bundle）

The source-map-explorer tool is a great way to inspect the generated JavaScript bundles after a production build.

source-map-explorer 是在生产环境构建中深入探查所生成的文件包的好工具。

Install source-map-explorer:

安装 source-map-explorer：

npm install source-map-explorer --save-dev

Build your app for production including the source maps

构建带源码映射的生产版本

ng build --prod --source-map

List the generated bundles in the dist/ folder.

列出 dist/ 文件夹中生成的文件包。

ls dist/*.bundle.js

Run the explorer to generate a graphical representation of one of the bundles. The following example displays the graph for the main bundle.

运行这个源码映射浏览器，以生成文件包之一的图形化表示。 下面的例子中就是 main 这个文件包的图形。

node_modules/.bin/source-map-explorer dist/main.*.bundle.js

The source-map-explorer analyzes the source map generated with the bundle and draws a map of all dependencies, showing exactly which classes are included in the bundle.

source-map-explorer 分析了文件包生成的源码映射信息，并画出了所有这些依赖的地图，准确的展示了这个包中包含了哪些类。

Here's the output for the main bundle of the QuickStart.

下面是《快速起步》一章生成的 main 文件包的输出。

quickstart sourcemap explorer

The base tag

base 标签

The HTML <base href="/..."/> specifies a base path for resolving relative URLs to assets such as images, scripts, and style sheets. For example, given the <base href="/my/app/">, the browser resolves a URL such as some/place/foo.jpg into a server request for my/app/some/place/foo.jpg. During navigation, the Angular router uses the base href as the base path to component, template, and module files.

HTML 中的<base href="/..."/>用于指定一个解析相对路径的基地址，如图片、脚本和样式表。 比如，指定 <base href="/my/app/"> 时，浏览器就会把 some/place/foo.jpg 这样的 URL 解析成到 my/app/some/place/foo.jpg 的服务端请求。 在浏览期间，Angular 路由器会使用base href作为组件、模板和模块文件的基地址。

See also the APP_BASE_HREF alternative.

参见另一种备选方案APP_BASE_HREF。

In development, you typically start the server in the folder that holds index.html. That's the root folder and you'd add <base href="/"> near the top of index.html because / is the root of the app.

在开发期间，你通常会在 index.html 所在的目录中启动服务器。这个目录就是根目录，因为 / 就是本应用的根，所以你要在 index.html 的顶部添加 <base href="/">。

But on the shared or production server, you might serve the app from a subfolder. For example, when the URL to load the app is something like http://www.mysite.com/my/app/, the subfolder is my/app/ and you should add <base href="/my/app/"> to the server version of the index.html.

但是在共享服务器或生产服务器上，你可能得从子目录下启动服务器。 比如，当加载本应用的 URL 是 http://www.mysite.com/my/app/ 时，子目录就是 my/app/，而你就要在服务器版的 index.html 中添加 <base href="/my/app/">。

When the base tag is mis-configured, the app fails to load and the browser console displays 404 - Not Found errors for the missing files. Look at where it tried to find those files and adjust the base tag appropriately.

当没有配置 base 标签时，加载应用就会失败，浏览器的控制台中会为这些缺失的文件显示一些 404 - Not Found 错误。 看看浏览器试图从哪里找这些文件，然后调整出合适的 base 标签。

build vs. serve

构建与服务

You'll probably prefer ng build for deployments.

你会更喜欢用 ng build 进行部署。

The ng build command is intended for building the app and deploying the build artifacts elsewhere. The ng serve command is intended for fast, local, iterative development.

ng build 命令的设计意图是构建该应用，并且把构建成果部署到别处。 而ng serve 命令的设计意图是快速进行本地的迭代式开发。

Both ng build and ng serve clear the output folder before they build the project. The ng build command writes generated build artifacts to the output folder. The ng serve command does not. It serves build artifacts from memory instead for a faster development experience.

在开始构建项目之前，ng build 和 ng serve 都会清空输出文件夹。 ng build 命令会把生成的构建成果写入输出文件夹中，但 ng serve 命令并不会如此。 它会用内存中的构建成果提供服务，以获得更快速的开发体验。

The output folder is dist/ by default. To output to a different folder, change the outputPath in angular.json.

默认的输出文件夹是 dist/。 要输出到其它文件夹中，请修改 angular.json 中的 outputPath。

The ng serve command builds, watches, and serves the application from a local CLI development server.

ng serve 命令会构建、监听并使用本地的 CLI 开发服务器作为服务器。

The ng build command generates output files just once and does not serve them. The ng build --watch command will regenerate output files when source files change. This --watch flag is useful if you're building during development and are automatically re-deploying changes to another server.

ng build 命令只会生成一次这些输出文件，而不会用它们提供服务。 ng build --watch 命令会在源码变化的时候重新生成输出文件。 当你在开发期间需要不断构建并自动把修改后的版本发布到另一台服务器的时候，这个 --watch 标志会很有用。

See the CLI build topic for more details and options.

参见 CLI 中的 build 主题以了解详情以及其它选项。

Server configuration

服务端配置

This section covers changes you may have make to the server or to files deployed to the server.

这一节涵盖了你可能对服务器或准备部署到服务器的文件要做的那些修改。

Routed apps must fallback to index.html

带路由的应用必须以 index.html 作为后备页面

Angular apps are perfect candidates for serving with a simple static HTML server. You don't need a server-side engine to dynamically compose application pages because Angular does that on the client-side.

Angular 应用很适合用简单的静态 HTML 服务器提供服务。 你不需要服务端引擎来动态合成应用页面，因为 Angular 会在客户端完成这件事。

If the app uses the Angular router, you must configure the server to return the application's host page (index.html) when asked for a file that it does not have.

如果该应用使用 Angular 路由器，你就必须配置服务器，让它对不存在的文件返回应用的宿主页(index.html)。

A routed application should support "deep links". A deep link is a URL that specifies a path to a component inside the app. For example, http://www.mysite.com/heroes/42 is a deep link to the hero detail page that displays the hero with id: 42.

带路由的应用应该支持“深链接”。 所谓深链接就是指一个 URL，它用于指定到应用内某个组件的路径。 比如，http://www.mysite.com/heroes/42 就是一个到英雄详情页面的深链接，用于显示 id: 42 的英雄。

There is no issue when the user navigates to that URL from within a running client. The Angular router interprets the URL and routes to that page and hero.

当用户从运行中的客户端应用导航到这个 URL 时，这没问题。 Angular 路由器会拦截这个 URL，并且把它路由到正确的页面。

But clicking a link in an email, entering it in the browser address bar, or merely refreshing the browser while on the hero detail page — all of these actions are handled by the browser itself, outside the running application. The browser makes a direct request to the server for that URL, bypassing the router.

但是，当从邮件中点击链接或在浏览器地址栏中输入它或仅仅在英雄详情页刷新下浏览器时，所有这些操作都是由浏览器本身处理的，在应用的控制范围之外。 浏览器会直接向服务器请求那个 URL，路由器没机会插手。

A static server routinely returns index.html when it receives a request for http://www.mysite.com/. But it rejects http://www.mysite.com/heroes/42 and returns a 404 - Not Found error unless it is configured to return index.html instead.

静态服务器会在收到对 http://www.mysite.com/ 的请求时返回 index.html，但是会拒绝对 http://www.mysite.com/heroes/42 的请求， 并返回一个 404 - Not Found 错误，除非，它被配置成了返回 index.html。

Fallback configuration examples

后备页面配置范例

There is no single configuration that works for every server. The following sections describe configurations for some of the most popular servers. The list is by no means exhaustive, but should provide you with a good starting point.

没有一种配置可以适用于所有服务器。 后面这些部分会描述对常见服务器的配置方式。 这个列表虽然不够详尽，但可以为你提供一个良好的起点。

Development servers

开发服务器

  • Lite-Server: the default dev server installed with the Quickstart repo is pre-configured to fallback to index.html.

    Lite-Server是"快速上手"仓库中安装的默认开发服务器，它被预先配置为回退到 index.html。

  • Webpack-Dev-Server: setup the historyApiFallback entry in the dev server options as follows:

    Webpack-Dev-Server在开发服务器的配置中设置了 historyApiFallback，代码如下：

    historyApiFallback: { disableDotRule: true, htmlAcceptHeaders: ['text/html', 'application/xhtml+xml'] }

Production servers

生产服务器

Requesting services from a different server (CORS)

请求来自另一个服务器的服务（CORS）

Angular developers may encounter a cross-origin resource sharing error when making a service request (typically a data service request) to a server other than the application's own host server. Browsers forbid such requests unless the server permits them explicitly.

Angular 开发者在向与该应用的宿主服务器不同域的服务器发起请求时，可能会遇到一种跨域资源共享（CORS）错误。 浏览器会阻止该请求，除非得到那台服务器的明确许可。

There isn't anything the client application can do about these errors. The server must be configured to accept the application's requests. Read about how to enable CORS for specific servers at enable-cors.org.

客户端应用对这种错误无能为力。 服务器必须配置成可以接受来自该应用的请求。 要了解如何对特定的服务器开启 CORS，参见enable-cors.org。