From 31933c93691dd3bb63cc4fd1665ed91543374e19 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Tue, 19 Apr 2022 13:28:00 -0400
Subject: [PATCH] doc: update readme to list env vars

---
 README.md | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/README.md b/README.md
index 6dc91437..11d3a00e 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,21 @@ let foo x =
   (* … *)
 ``` 
 
+## Configuration
+
+The library is configurable via `Opentelemetry.Config`, via the standard
+opentelemetry env variables, or with some custom environment variables.
+
+- `OTEL_EXPORTER_OTLP_ENDPOINT` sets the http endpoint to send signals to
+- `OTEL_OCAML_DEBUG=1` to print some debug messages from the opentelemetry library ide
+- `OTEL_RESOURCE_ATTRIBUTES` sets a comma separated list of custom resource attributes
+
+## Collector opentelemetry-client-ocurl
+
+This is a synchronous collector that uses the http+protobuf format
+to send signals (metrics, traces) to some other collector (eg. `otelcol`
+or the datadog agent).
+
 ## License
 
 MIT