Configure custom layers for a function - Function Compute

Use the Function Compute console

Before you start

Procedure

When you configure a layer for a function, one version of the layer is bound to the function based on your business requirements if the layer has multiple versions.

Log on to the Function Compute console. In the left-side navigation pane, click Services & Functions.
In the top navigation bar, select a region. On the Services page, click the desired service.
On the Functions page, find the desired function and click Configure in the Actions column.
In the Layers section, click + Add Layer and select Add Custom Layer from the drop-down list. Select options from the Custom Layer and Layer Version drop-down lists, and then click Save.

Note

A function can be configured with a maximum of five layers, including custom layers and official public layers.
When multiple layers are configured for a function, the content of these layers is merged and stored in the /opt directory in reverse order. If layers contain files with the same name, the files in the first configured layer overwrites the files with the same names in the later configured layer.

Use Serverless Devs

Prerequisites

Procedure

Run the following command to query the custom layers in the specified region:
```
s cli fc layer list --custom --region cn-hangzhou
```
After the execution, the custom layer list is returned. Obtain and record the value of arn of the desired layer.

Note In the returned custom layer information, the value of the arn field is about to be deprecated. We recommend that you use the value of the arnV2 field as the ARN of the custom layer.
```
-
  layerName:         java11_fc_auto_created
  arn:               ec284ee1c033fa7fc68ffcd44c******#java11_fc_auto_created#1
  arnV2:             acs:fc:cn-hangzhou:164901546557****:layers/java11_fc_auto_created/versions/1
  version:           1
  acl:               0
  description:
  compatibleRuntime:
    - custom
```
The following items describe the code snippets in the sample code:
- layerName: the name of the layer.
- version: the version of the layer.
- arn: the original ARN of the layer. The original ARN can be used only in custom layers.
- arnV2: the new ARN of the layer. The new ARN can be used in custom layers and official public layers.
- acl: the permissions of the layer. The digit 0 specifies that the layer is private and the digit 1 specifies that the layer is public. By default, the official public layers are public. The custom layers can be set to private or public.
- description: the description of the layer.
- compatibleRuntime: specifies the list of compatible runtime environments.

Create the s.yaml file in any directory and enter the obtained layer arn.

Example:

edition: 1.0.0          # The version of the YAML specification. The version complies with the semantic versioning specification.
name: fcDeployApp       #  The name of the project.
access: "default"  #  The alias of the key.

services:
  fc-deploy-test: # The name of the service.
    component: fc  # The name of the component.
    props: #  The attribute value of the component.
      region: cn-hangzhou
      service:
        name: fctest
        description: 'test'
        internetAccess: true
      function:
        name: emoji # The name of the function.
        description: this is a emoji
        runtime: java11
        codeUri: ./
        handler: index.handler
        memorySize: 128
        timeout: 6
        layers:    # The layers bound to the function. The values are the ARNs of the layers.
          - acs:fc:cn-hangzhou:164901546557****:layers/java11_fc_auto_created/versions/1

Run the following command in the directory in which the s.yaml file is stored to deploy the function and configure the layers for the function:
```
s deploy
```

Additional information

You can also use API operations or SDKs to manage and configure layers. You can configure layers by calling the following API operations:

You can use OpenAPI Explorer to call API operations and use SDKs.