Shulou(Shulou.com)06/03 Report--

Author: Yi Xian

First of all, we introduce several important concepts that appear in this article:

Function computing (Function Compute): function computing is an event-driven service. Through function calculation, users do not need to manage the operation of the server, but only need to write code and upload. The function calculation prepares the computing resources and runs the user code in an elastic way, while the user only needs to pay according to the resources consumed by the actual code. Function to calculate more information.

ImageMagick:ImageMagick is an open source software suite for viewing, editing bitmap files, and converting image formats. It can read and edit more than 100 image formats. See Wikipedia entry

ImageMagick is a sharp tool for image processing, with the help of ImageMagick, you can easily achieve picture cropping and scaling. Although many languages encapsulate the call library of ImageMagick, it is often not suitable for the software architecture to put the picture processing function and the core business function in the same service. There are two reasons:

On the one hand, image processing depends on external bin, and the compiled two-tier system does not have portability, which brings trouble to packaging and distribution. On the other hand, picture processing often consumes computing resources, and for most business systems, picture processing belongs to marginal business rather than core business, so it is not cost-effective to reserve more computing resources for the whole service. A better choice is to split the image processing business into micro-services and deploy them on resilient underlying services. For this kind of technical requirements, Serverless is very appropriate.

This article focuses on how to quickly deploy a flexible and highly available image processing service on the function computing platform, and then easily customize on this basis.

Quick start

Next, with the help of Tencent App Center calculated by the function, we can quickly deploy the image conversion service.

Open the details page of the function calculation Image Resizer application. If you have not activated the function computing service, you may need to activate the service first. The service is free of charge. In addition, there is a monthly free quota for function calculation, and there is no fee for the trial service.

Scroll to the bottom of the Image Resizer application details page and click the "deploy now" button.

Fill in the application name: my-image-resizer, and then click the "deploy" button.

Copy the URL in HttpTriggerEndpoint.

Open the above URL in the browser, or call it through curl. Note: since the domain name is not bound, the application center will download the image by default instead of opening it directly in the browser.

Curl 'https://xxxxx.cn-shanghai.fc.aliyuncs.com/2016-08-15/proxy/my-image-resizer-ResizeService-5A40B5A8B981/my-image-resizer-ResizeFunction-3E71C57C0094/'-- how output resized.jpg works

This is a single function combined with Http Trigger application. Http Trigger exposes the service in the HTTP GET method, and the client passes three request parameters: url, width, and height. Among them

Url indicates the address of the source picture that needs to be processed width indicates the width of the cropped or scaled picture height represents the width of the cropped picture. When this parameter is missing, the picture is adjusted by zooming.

The architecture of the application is as follows:

After the FC function receives the HTTP request, it performs the following three steps:

Download the picture pointed to by url and use imagemagick to convert the picture and return the picture to the client through http protocol.

Above we passed the function calculation of Tencent App Center quickly online a picture conversion service. The calculation of the function is charged according to the number of calls, so there is no charge for the above services even if they are kept online. And because the function calculation has a free quota every month, there is no cost for daily development calls.

Customized development dependency tools

This project is developed under MacOS, the tools involved are platform-independent, and should also be applicable to Linux and Windows desktop systems. Before starting this example, make sure that the following tools are installed correctly, updated to the latest version, and configured correctly.

DockerFuncraft

The Fun tool relies on docker to simulate the local environment.

For MacOS users, you can use homebrew to install:

Brew cask install dockerbrew tap vangie/formulabrew install fun

For Windows and Linux user installation, please refer to:

Https://github.com/aliyun/fun/blob/master/docs/usage/installation.md

After installation, remember to initialize the configuration by executing fun config first.

Note that if you have already installed funcraft, make sure that the funcraft version is above 3.1.3.

$fun-- version3.1.3 initializes git clone https://github.com/vangie/fc-image-resizercd fc-image-resizer installation depends on npm install local running $fun local startusing template: .fun / build/artifacts/template.ymlHttpTrigger httpTrigger of ResizeService/ResizeFunction was registered url: http://localhost:8000/2016-08-15/proxy/ResizeService/ResizeFunction methods: ['GET'] authType: ANONYMOUSfunction compute app listening on port 8000!

Then use the browser or curl to debug the URL http://localhost:8000/2016-08-15/proxy/ResizeService/ResizeFunction

Deploy fun deploy

In order to get a better development experience, it is recommended to install Aliyun Serverless VSCode Extension

Reference link FuncraftAliyun Serverless VSCode Extension

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