Developing and Reusing Application Template

Last updated: 2021-03-29 15:51:15

    Overview

    Serverless Framework provides multiple basic resource components, which you can mix and use to quickly create and deploy resources in the cloud. This document describes how to use existing components to build your own multi-component serverless application template.

    Prerequisites

    You have installed Serverless Framework on at least the following versions:

    $ serverless –v
    Framework Core: 2.16.1
    Plugin: 4.3.0
    SDK: 2.3.2
    Components: 3.4.3
    

    Component Configuration Documentation

    Directions

    This document uses deploying a framework project based on Layer and Egg as an example to describe how to import multiple components into your project and quickly complete the deployment. The steps are as follows:

    Step 1. Create a project

    Create a project app-demo and enter this directory:

    $ mkdir app-demo && cd app-demo
    

    Step 2. Build an Egg project

    1. In the app-demo directory, create a src folder and create an Egg project in it:

      $ mkdir src && cd src
      $ npm init egg --type=simple
      $ npm i
      
    2. In the src directory, write the configuration file serverless.yml:

      $ touch serverless.yml
      

      A sample .yml file for the Egg component is provided below. For more information on all configuration items, please see Egg.js Component Configuration.

    # serverless.yml
    app: app-demo # Application name. The `app`, `stage`, and `org` parameters must be the same for each component under the same application
    stage: dev
    component: egg 
    name:  app-demo-egg # Name of the created instance, which is required
    
    inputs:
      src:   
        src: ./    # Project path for upload
        exclude:   # Exclude the `node_modules` and `.env` file
          - .env
          - node_modules
      region: ap-guangzhou
      functionName: eggDemo  # Function configuration
      runtime: Nodejs10.15
      apigatewayConf:
        protocols:           # API Gateway trigger configuration. A gateway will be created by default
          - http
          - https
        environment: release
    

    Note:

    • The app, stage, and org parameters must be the same for the resources created by each component under the same project.
    • The Egg component essentially creates an API Gateway trigger + SCF resource. Here, you can select different components according to your actual development needs, and the configuration methods are similar. For more information, please see Component Configuration Documentation.

    Step 3. Create a layer

    Go back to the root directory of app-demo, create a layer folder, and create a layer configuration file serverless.yml in it:

    $ cd ..
    $ mkdir layer && cd layer
    $ touch serverless.yml
    

    serverless.yml can be configured according to the following template (for more information on the configuration, please see Layer Component Configuration):

    # serverless.yml
    app: app-demo # Application name. The `app`, `stage`, and `org` parameters must be the same for each component under the same application
    stage: dev
    component: layer 
    name:  app-demo-layer # Name of the created instance, which is required
    
    inputs:
      region: ap-guangzhou
      src: 
        src: ../src/node_modules # Path of the project you want to upload to the layer. `node_modules` is used as an example here
        targetDir: /node_modules # File compression directory after upload
      runtimes:
        - Nodejs10.15
    

    Note:

    • The app, stage, and org parameters must be the same for the resources created by each component under the same project.
    • The Layer component also supports importing projects from COS buckets. For more information, please see Layer Component Configuration. When entering the bucket parameter, be sure not to include -${appid}, as the component will add it automatically.

    Step 4. Organize the resource relationship

    In the same application, you can organize the creation order of resources according to their dependency relationship. Taking this project as an example, you need to create a layer first and then use the layer in the Egg.js project; therefore, you should ensure that the resource creation order is * layer > Egg.js application*. The specific steps are as follows:

    Modify the .yml configuration file of the Egg.js project, configure the layer configuration according to the following syntax, and import the deployment output of the Layer component as the deployment input of the Egg.js project to ensure that the Layer component is created before the Egg.js project:

    $ cd ../src
    

    In serverless.yml, add layer configuration in the inputs section:

    inputs:
      src:   
        src: ./    
        exclude:  
          - .env
          - node_modules
      region: ap-guangzhou
      functionName: eggDemo  
      runtime: Nodejs10.15
      layers:   # Add the layer configuration
        - name: ${output:${stage}:${app}:app-demo-layer.name} # Layer name
          version: ${output:${stage}:${app}:app-demo-layer.version} # Version
      apigatewayConf:
        protocols:        
          - http
          - https
        environment: release
    

    For the variable import format, please see Variable Import Description.

    At this point, the serverless application has been built, and the project directory structure is as follows:

       ./app-demo
       ├── layer
       │   └── serverless.yml # Layer configuration file
       ├── src
       │   ├── serverless.yml # Egg component configuration file
       │   ├── node_modules # Project dependency file
       │   ├── ...
       │   └── app # Project routing file
       └── .env # Environment variable file
    

    Step 5. Deploy the application

    In the project root directory, run sls deploy to complete layer creation and use the output of the Layer component as the input of the Egg.js component to cloudify the Egg.js framework.

     $ sls deploy
    
    serverless ⚡framework
    
    app-demo-layer: 
      region:        ap-guangzhou
      name:          layer_component_xxx
      bucket:        sls-layer-ap-guangzhou-code
      object:        layer_component_xxx.zip
      description:   Layer created by serverless component
      runtimes: 
        - Nodejs10.15
      version:       3
      vendorMessage: null
    
    app-demo-egg: 
      region:        ap-guangzhou
      scf: 
        functionName: eggDemo
        runtime:      Nodejs10.15
        namespace:    default
        lastVersion:  $LATEST
        traffic:      1
      apigw: 
        serviceId:   service-xxxx
        subDomain:   service-xxx.gz.apigw.tencentcs.com
        environment: release
        url:         https://service-xxx.gz.apigw.tencentcs.com/release/
      vendorMessage: null
    
    76s › app-demo › "deploy" ran for 2 apps successfully.
    

    You can click the URL output by apigw to access the created application, run sls info to view the status of the deployed instance, or run sls remove to quickly remove the application.

    Step 6. Publish the application template

    After the serverless project template is built, Serverless Framework allows you to publish it in the Serverless Registry for use by your team and others.

    1. Create a configuration file

    In the root directory, create a serverless.template.yml file, and the project directory structure is as follows:

    ./app-demo
    ├── layer
    │   └── serverless.yml # Layer configuration file
    ├── src
    │   ├── serverless.yml # Egg component configuration file
    │   ├── node_modules # Project dependency file
    │   ├── ...
    │   └── app # Project routing file
    ├── .env # Environment variable file
    └── serverless.template.yml # Template project description file
    

    2. Configure and publish the project template file

     # serverless.template.yml
    name: app-demo # Project template name, which must be unique
    displayName: Egg.js project template created based on layer # Name of the project template displayed in the console
    author: Tencent Cloud, Inc. # Author name
    org: Tencent Cloud, Inc. # Organization name, which is optional
    type: template # Project type, which can be either `template` or `component`. It is `template` here
    description: Deploy an egg application with layer. # Describe your project template
    description-i18n:
      zh-cn: Egg.js project template created based on layer # Description
    keywords: tencent, serverless, eggjs, layer # Keywords
    repo:  # Source code repo, which is usually your GitHub repo
    readme:  # Detailed description file, which is usually your GitHub repo README file
    license: MIT # Copyright notice
    src: # Describe the files in the project to be published as a template
      src: ./ # Specify a relative directory, the files under which will be published as a template
      exclude: # Describe the files in the specified directory to be excluded
        # The following files are usually excluded
        # 1. Files containing `secrets`
        # 2. Files managed by `.git` git source code
        # 3. Third-party dependencies such as `node_modules`
        - .env
        - '**/node_modules'
        - '**/package-lock.json'
    

    After the serverless.template.yml file is configured, you can use the sls publish command to publish the project to the Registry as a template.

    $ sls publish
    
    serverless ⚡registry
    Publishing "app-demo@0.0.0"...
    
    Serverless › Successfully published app-demo
    

    3. Reuse the template

    After your template is published, others can quickly download it and reuse the project by running the sls init command.

    $ sls init app-demo --name example
    $ cd example
    $ npm install
    

    Variable Import Description

    serverless.yml supports multiple ways to import variables:

    • Import basic Serverless parameters
      In the inputs field, you can directly import basic Serverless parameter configuration information through the ${org} and ${app} syntax.

    • Import environment variables
      In serverless.yml, you can directly import the environment variable configuration (including the environment variable configuration in the .env file and variable parameters manually configured in the environment) through the ${env} syntax.

      For example, you can import the environment variable REGION through ${env:REGION}.

    • Import the output results of other components
      If you want to import the output information of other component instances into the current component configuration file, you can configure it by using the following syntax:
      ${output:[app]:[stage]:[instance name].[output]}

    Sample .yml file:

    app: demo
    component: scf
    name: rest-api
    stage: dev
    
    inputs:
      name: ${stage}-${app}-${name} # The final name is "acme-prod-ecommerce-rest-api"
      region: ${env:REGION} # `REGION=` information specified in the environment variable
      vpcName: ${output:prod:my-app:vpc.name} # Get the output information of other components
      vpcName: ${output:${stage}:${app}:vpc.name} # The above methods can also be used in combination