Add layer for Datadog extension

[ramsey]

This PR adds a layer containing the Datadog Agent and ddtrace extension, following the approach @deleugpn describes at https://blog.deleu.dev/datadog-aws-lambda-php/

I have built the layers and tested this with my own serverless application, and it properly sends logging and tracing information to Datadog.

Here's an example serverless.yml configuration for this layer:

service: my-service

custom:
  datadog:
    apiKey: ${env:DD_API_KEY}
    env: ${env:MY_DEPLOYMENT_ENVIRONMENT}
    logLevel: ${env:DD_LOG_LEVEL, 'warn'}
    service: ${self:service}
    version: ${env:MY_VERSION}

plugins:
  - ./vendor/bref/bref
  - ./vendor/bref/extra-php-extensions

provider:
  name: aws
  region: us-east-1
  runtime: provided.al2
  layers:
    - ${bref:layer.php-82}
    - ${bref-extra:datadog-php-82}
  deploymentMethod: direct
  environment:
    DD_API_KEY: ${self:custom.datadog.apiKey}
    DD_ENV: ${self:custom.datadog.env}
    DD_LOG_LEVEL: ${self:custom.datadog.logLevel}
    DD_SERVICE: ${self:custom.datadog.service}
    DD_TRACE_CLI_ENABLED: 1
    DD_VERSION: ${self:custom.datadog.version}

functions:
  sayHello:
    handler: ./src/sayHello.php

This closes #35, when accepted.

[maksym-odanets]

Hey Ramsey, team

Re that article you are referring (https://blog.deleu.dev/datadog-aws-lambda-php/)
We also followed it to integrate DD into Bref Laravel lambda.

After integration, found lots of notices in CloudWatch like:
NOTICE: PHP message: Error loading deferred integration 'DDTrace\Integrations\Predis\PredisIntegration' from DDTrace\Integrations\load_deferred_integration
(*the same is for eloquent, pdo etc)

Right now - discussing that issue with DD support.

I wonder - does anyone have the same notices?

[ramsey]

@wolflingorg, the blog post doesn't mention copying over the integrations, which it sounds like you're trying to use. In order to use those, you need a line like this:

COPY --from=ext /opt/datadog/ /opt/datadog

You also need to make sure your Datadog INI settings are configured to link properly to the integrations code in /opt/datadog, which the default 98-ddtrace.ini file includes.

This is all handled in this pull request. If you'd like to give it a try and report back, that would help a lot. Thanks!

[maksym-odanets]

Hey,

Thanks for sharing an example & comments. You're right, looks like we missed something. After applying what you suggested, all looks good.

Thanks a lot

The only thing I noticed: you installed DD without an "--enable-profiling" flag (and also commented out profiling in the .ini file)... Is there any reason why?

[ramsey]

The only thing I noticed: you installed DD without an "--enable-profiling" flag (and also commented out profiling in the .ini file)... Is there any reason why?

My understanding is that profiling is still in beta. The extension .so file is still available in the layer, so if you want to enable it, you can follow the instructions for Bref to create custom INI configuration and enable it.

[mnapoli]

Hi, to provide some update here: on my end it looks good, but unfortunately we released Bref v2 which impacts the build here. I'm afraid you would have to rebase (you can look at how Dockerfiles look in the repo now to get some examples)

[fbnfgc]

Hi, we are looking forward to use datadog. We're still using bref v1 but we are planning to migrate to v2 in a near future. Are you still working on this @ramsey? Do you need some help?

[ramsey]

I went in a different direction, for now. Soon, I’ll open a new pull request with the changes I made.

[fbnfgc]

Thanks!