Koa application migration

Midway Serverless provides a general application migration scheme, which can publish the original application to the function platform without modifying the code as much as possible. with this solution, you can migrate the original koa application to the function platform for hosting as quickly and simply as possible, and enjoy the elastic bonus of the cloud native era.

Add function configuration

Add the f.yml file to the root directory of the code.

service: my-koa-demo

provider:
  name: aliyun ## cloud platform, aliyun,tencent, etc

deployType: koa ## Deployed Application Type

package:
  exclude:
    -package-lock.json ## Ignore package-lock.json files

custom:
  customDomain:
    domainName: auto ## automatically generates domain name

info

Sometimes package-lock.json files will cause the deployment package to be too large (enter dev dependencies).

Code modification

• 1. The default app needs to be exported
• 2. The current file name of the project file must be app.js.
• 3. index.js is a reserved file. Do not include this file in the project.

// app.js

const Koa = require('koa');
const Router = require('koa-router');
const app = new Koa();

// * * * * *

// Comment on the original listening
// app.listen(3000);

// Export the default app
module.exports = app;

If there is asynchronous initialization, such as connecting to a database, we provide asynchronous support.

// app.js

const Koa = require('koa');
const Router = require('koa-router');
const app = new Koa();

// * * * * *

// Comment on the original listening
// app.listen(3000);

// Export the default app
module.exports = async () => {
  // do some async method, like db connect
  return app;
};

Static resources

If you want to build a copied directory in the root directory of the project, such as the public directory of static files, configure the package.include field in f.yml.

service: my-koa-demo

provider:
  name: aliyun ## cloud platform, aliyun,tencent, etc

deployType:
  type: koa               ## Deployed Application Type
  version: 3.0.0

package:
  include:
    -public ## will be automatically packaged when written here.
  exclude:
    -package-lock.json ## Ignore package-lock.json files

Deployment

In the package.json configuration Scripts script and dev dependency @midwayjs/cli, execute npm run deploy.

{
  "devDependencies": {
    "@midwayjs/cli": "^1.2.36"
    ...
  },
  "scripts": {
    "deploy": "midway-bin deploy ",
    ...
  }
}

Or use a different npm package to accelerate.

{
  "scripts": {
    "deploy": "midway-bin deploy --npm=cnpm ",
    ...
  }
}

You can also execute commands separately.

$ npx midway-bin deploy                                     ## deploy by npm
$ npx midway-bin deploy --npm=cnpm ## deploy by cnpm

Default

Aliyun

By default, it is published as an http trigger. If you need an API gateway, you can modify and configure the functions structure according to the format of f.yml. At the same time, you need to configure routes on the platform.

Tencent cloud

By default, it is published as an API gateway trigger and the gateway route is automatically configured.

Modify the deployed function name

You can use the name field.

service: my-demo 

provider:
  name: aliyun ## cloud platform, aliyun,tencent, etc

deployType:
  type: koa
  version: 3.0.0
  Name: app_idx ## function name