Description

Running PHP inside Lambda layers using stackery php-lambda-layer

Key Aspects

• Leverage Lambda Layers for the PHP custom runtime
• Set the Lambda handler as index.php
• Use AWS Serverless Application Model (SAM) to package and deploy your HTTP application
• Use an external API definition tool, such as Swagger, to scaffold client and server contracts. This shortens development time by generating client side and server side communication components, thus allowing you to write only the functionallity not the communication mechanisms. See Swagger Codegen

Files

file	description
src/index.php	Main file handler
src/json-response.php	Sets JSON header and encodes response data object
src/php.ini	Includes json.so to encode json response
template.yaml	SAM CloudFormation template which includes PHP Lambda Layer

Included Extensions

The following extensions are built into the layer:

PHP 7.3 Layer:

bz2.so
calendar.so
ctype.so
curl.so
dom.so
exif.so
fileinfo.so
ftp.so
gettext.so
iconv.so
json.so
mbstring.so
mysqli.so
mysqlnd.so
pdo_mysql.so
pdo_pgsql.so
pdo.so
pdo_sqlite.so
pgsql.so
phar.so
posix.so
shmop.so
simplexml.so
sockets.so
sqlite3.so
sysvmsg.so
sysvsem.so
sysvshm.so
tokenizer.so
wddx.so
xmlreader.so
xml.so
xmlwriter.so
xsl.so

Using AWS SAM (Serverless Application Model)

Create a basic SAM application:

$ mkdir app
$ cd app

Create a template.yaml file with the following SAM infrastructure:

AWSTemplateFormatVersion: 2010-09-09
Description: My PHP Application
Transform: AWS::Serverless-2016-10-31
Resources:
  phpserver:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: !Sub ${AWS::StackName}-phpserver
      Description: PHP Webserver
      CodeUri: src
      Runtime: provided
      Handler: index.php
      MemorySize: 3008
      Timeout: 30
      Tracing: Active
      AutoPublishAlias: live
      DeploymentPreference:
        Type: Linear10PercentEvery10Minutes
      Layers:
        - !Sub arn:aws:lambda:${AWS::Region}:887080169480:layer:php73:3
      Events:
        api:
          Type: Api
          Properties:
            Path: /{proxy+}
            Method: ANY

Last create index.php in the src directory

<?
include 'json-response.php';

// get the JSON request and serialize it
$data = json_decode(file_get_contents('php://input'), true);

// create response object
$response = [ 'context' => 'custom-runtime-example', 'age' => $data ];

// return response
send_json_response($response);
?>

Deplying

Run the following commands:

$ sam package \
    --template-file template.yaml \
    --output-template-file serverless-output.yaml \
    --s3-bucket <your SAM deployment bucket created above>

# Deploying directly using SAM. Recommendation is to use a CI/CD like AWS CodePipeline
$ sam deploy \
    --template-file serverless-output.yaml \
    --stack-name my-first-serverless-php-service \
    --capabilities CAPABILITY_IAM

Packaging using AWS CodeBuild

Use the following in your buildspec.yaml

version: 0.2

phases:
  install:
    runtime-versions:
       python: 3.7
    commands:
      - pip install cfn-lint
  build:
    commands:
      - cfn-lint -t template.yaml
      - aws cloudformation package --template-file template.yaml --s3-bucket ${PACKAGE_BUCKET} --output-template-file packaged-template.yaml
artifacts:
  files:
    - packaged-template.yaml

Deploying using CodeDeploy

Copy and modify the template.yaml from https://github.com/awslabs/aws-sam-codepipeline-cd/blob/master/sam/app/template.yaml

Additional Resources

• AWS Lambda Custom Runtime for PHP: A Practical Example
• Using AWS Lambda Layers for PHP
• Bref Lambda Layers
• Safe Lambda deployments