rfc(decision): Environment Variable conventions

README.md

@@ -60,6 +60,7 @@ This repository contains RFCs and DACIs. Lost?
 - [0116-sentry-semantic-conventions](text/0116-sentry-semantic-conventions.md): Sentry Semantic Conventions
 - [0118-mobile-transactions-and-spans](text/0118-mobile-transactions-and-spans.md): Transactions and Spans for Mobile Platforms
 - [0119-rust-in-sentry](text/0119-rust-in-sentry.md): Make it easier to use Rust code from Sentry/Python.
+- [0121-draft-environment-variable-conventions](text/0121-draft-environment-variable-conventions.md): Environment Variable conventions
 - [0123-metrics-correlation](text/0123-metrics-correlation.md): This RFC addresses the high level metrics to span correlation system
 - [0126-sdk-spans-aggregator](text/0126-sdk-spans-aggregator.md): SDK Spans Aggregator
 - [0129-video-replay-envelope](text/0129-video-replay-envelope.md): Video-based replay envelope format

text/0121-draft-environment-variable-conventions.md

@@ -0,0 +1,46 @@
+- Start Date: 2023-11-07
+- RFC Type: decision
+- RFC PR: https://github.com/getsentry/rfcs/pull/121
+- RFC Status: draft
+
+# Summary
+
+We already expose certain environment variables that are consumed by SDKs, such as `SENTRY_DSN` and `SENTRY_RELEASE`.
+To further ease usage, we should expose more options as such.
+This RFC aims to find a set of conventions mainly aimed for server-side SDKs.
+
+# Motivation
+
+Changing the SDK configuration most often requires a re-deployment of the application. This can be cumbersome for small changes,
+such as updating the `traces_sample_rate`. Given the rise in populairty of server-less or containerized deployments, where
+most configuration hails from envrionment variables, we should strive to make this workflow less cumbersome for our users.
+
+# Background
+
+The Laravel SDK exposes the majority of its configuration as environment variables, making it a breeze to update the configuration of the SDK easily.
+For a complete list of exposed variables, see https://github.com/getsentry/sentry-laravel/blob/9624a88c9cd9a50c22443fcdf3a0f77634b11210/config/sentry.php
+
+# Options Considered
+
+A first list of environment variables that all server sides SDKs should support could look like:
+
+- `SENTRY_DSN`
+- `SENTRY_RELEASE`
+- `SENTRY_ENVIRONMENT`
+- `SENTRY_SAMPLE_RATE`
+- `SENTRY_TRACES_SAMPLE_RATE`
+- `SENTRY_PROFILES_SAMPLE_RATE`
+- `SENTRY_DEBUG`
+
+Further additions could include but are not limited to:
+
+- `SENTRY_TAGS_<tag-key>` - An environment variable of `SENTRY_TAGS_foo = "bar"` would result in a tag of `foo: bar` being attached to all events.
+
+or SDK/framework-specific options, such as to control integrations or features
+
+- `SENTRY_BREADCRUMBS_LOGS_ENABLED`
+- `SENTRY_TRACE_MISSING_ROUTES_ENABLED`
+
+# Drawbacks
+
+TBD