https://cloud.google.com/appengine/docs/standard/go112/runtime
| GAE_APPLICATION | The ID of your App Engine application. This ID is prefixed with 'region code~' such as 'e~' for applications deployed in Europe. |
| GAE_DEPLOYMENT_ID | The ID of the current deployment. |
| GAE_ENV | The App Engine environment. Set to standard. |
| GAE_INSTANCE | The ID of the instance on which your service is currently running. |
| GAE_MEMORY_MB | The amount of memory available to the application process, in MB. |
| GAE_RUNTIME | The runtime specified in your app.yaml file. |
| GAE_SERVICE | The service name specified in your app.yaml file. If no service name is specified, it is set to default. |
| GAE_VERSION | The current version label of your service. |
| GOOGLE_CLOUD_PROJECT | The GCP project ID associated with your application. |
| NODE_ENV | Set to production when your service is deployed. |
| PORT | The port that receives HTTP requests. |
https://cloud.google.com/functions/docs/env-var
| ENTRY_POINT | Reserved: The function to be executed. |
| GCP_PROJECT | Reserved: The current GCP project ID. |
| GCLOUD_PROJECT | Reserved: The current GCP project ID (deprecated). |
| GOOGLE_CLOUD_PROJECT | Reserved: Not set but reserved for internal use. |
| FUNCTION_TRIGGER_TYPE | Reserved: The trigger type of the function. |
| FUNCTION_NAME | Reserved: The name of the function resource. |
| FUNCTION_MEMORY_MB | Reserved: The maximum memory of the function. |
| FUNCTION_TIMEOUT_SEC | Reserved: The execution timeout in seconds. |
| FUNCTION_IDENTITY | Reserved: The current identity (service account) of the function. |
| FUNCTION_REGION | Reserved: The function region (example: us-central1). |
https://cloud.google.com/run/docs/reference/container-contract#env-vars
| PORT | The port your HTTP server should listen on. 8080 |
| K_SERVICE | The name of the Cloud Run service being run. hello-world |
| K_REVISION | The name of the Cloud Run revision being run. hello-world.1 |
| K_CONFIGURATION | The name of the Cloud Run configuration that created the revision. hello-world |
https://docs.aws.amazon.com/lambda/latest/dg/lambda-environment-variables.html
| _HANDLER | The handler location configured on the function. |
| AWS_REGION | The AWS region where the Lambda function is executed. |
| AWS_EXECUTION_ENV | The runtime identifier, prefixed by AWS_Lambda_. For example, AWS_Lambda_java8. |
| AWS_LAMBDA_FUNCTION_NAME | The name of the function. |
| AWS_LAMBDA_FUNCTION_MEMORY_SIZE | The amount of memory available to the function in MB. |
| AWS_LAMBDA_FUNCTION_VERSION | The version of the function being executed. |
| AWS_LAMBDA_LOG_GROUP_NAME, AWS_LAMBDA_LOG_STREAM_NAME | The name of the Amazon CloudWatch Logs group and stream for the function. |
| AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN | Access keys obtained from the function's execution role. |
| TZ | The environment's timezone (UTC). The execution environment uses NTP to synchronize the system clock. |
| LAMBDA_TASK_ROOT | The path to your Lambda function code. |
| LAMBDA_RUNTIME_DIR | The path to runtime libraries. |
| AWS_LAMBDA_RUNTIME_API | Yes |