This document describes how to use a layer in the Serverless console.
Instructions
Files in the layer are all under the /opt/ directory, which can be accessed through their absolute paths in the function code. In addition, the built-in environment variables of each runtime also include layer paths, so files can be uploaded according to such paths, and then they can be imported through their relative paths in the code.
For the environment variables in Python, Java, and Node.js, see the table below:
The following takes importing the cos-nodejs-sdk-v5 dependency from node_modules in a layer in the code in the Node.js runtime environment as an example:
1. Upload node_modules to generate a layer as instructed in Creating layer. The local function directory structure is as shown below:
2. Package and upload the local function code as instructed in Deploying Function. During the packaging, run the following command to exclude the node_modules folder:
4. You can import files at the layer in the function after completing the steps above.
'use strict'
varCOS=require('cos-nodejs-sdk-v5')
Note:
As the NODE_PATH environment variable already includes the /opt/node_modules path, there is no need to specify the absolute path of the dependency. SCF will load the file according to the path specified in the environment variable during execution.
If the file path in the layer and the path included in the environment variable are different, you need to use the absolute path when importing the file.
Python
The following takes importing the cos-python-sdk-v5 dependency from a layer in the code in the Python runtime environment as an example:
1. Upload cos-python-sdk-v5 to generate a layer as instructed in Creating layer.
2. Package and upload the local function code as instructed in Deploying Function. Files that have already been uploaded to the layer don't need to be uploaded again together with the function code.
4. You can import files at the layer in the function after completing the steps above.
# -*- coding: utf8 -*-
import cos-python-sdk-v5
Note:
As the PYTHONPATH environment variable already includes the /opt path, there is no need to specify the absolute path of the dependency. SCF will load the file according to the path specified in the environment variable during execution.
If the file path in the layer and the path included in the environment variable are different, you need to use the absolute path when importing the file.
Sample
Using layer and testing function
1.
Go to
scf_layer_demo and select Clone or download > Download ZIP to download the demo and decompress it.
