From f8efdb749428a00985ce6f09b630c753c5c92004 Mon Sep 17 00:00:00 2001
From: Jamie Magee <jamagee@microsoft.com>
Date: Thu, 24 Mar 2022 15:07:01 -0700
Subject: [PATCH] docs: document environment variables

Closes #80
---
 docs/detectors/go.md          |  7 +++++++
 docs/detectors/pip.md         |  5 +++++
 docs/environment-variables.md | 15 +++++++++++++++
 3 files changed, 27 insertions(+)
 create mode 100644 docs/environment-variables.md

diff --git a/docs/detectors/go.md b/docs/detectors/go.md
index 6f48d9b70..b47111819 100644
--- a/docs/detectors/go.md
+++ b/docs/detectors/go.md
@@ -36,3 +36,10 @@ Go detection will fallback if no Go v1.11+ is present.
 
 Due to the nature of `go.sum` containing references for all dependencies, including historical, no-longer-needed dependencies; the fallback strategy can result in over detection.
 Executing `go mod tidy` before detection via fallback is encouraged.
+
+## Environment Variables
+
+If the environment variable `EnableGoCliScan` is set, to any value, the Go detector uses [`go mod graph`][1] to discover Go dependencies.
+If the environment variable is not present, we fall back to parsing `go.mod` and `go.sum` ourselves.
+
+[1]: https://go.dev/ref/mod#go-mod-graph
diff --git a/docs/detectors/pip.md b/docs/detectors/pip.md
index 0bb4f3e25..4a7d24da3 100644
--- a/docs/detectors/pip.md
+++ b/docs/detectors/pip.md
@@ -35,3 +35,8 @@ Pip detection will not run if `python` is unavailable.
 If no `bdist_wheel` or `bdist_egg` are available for a given component, dependencies will not be fetched.
 
 If no internet connection or a component cannot be found in Pypi, said component and its dependencies will be skipped.
+
+## Environment Variables
+
+The environment variable `PyPiMaxCacheEntries` is used to control the size of the in-memory LRU cache that caches responses from PyPi.
+The default value is 128.
diff --git a/docs/environment-variables.md b/docs/environment-variables.md
new file mode 100644
index 000000000..6ce77ec03
--- /dev/null
+++ b/docs/environment-variables.md
@@ -0,0 +1,15 @@
+# Environment Variables
+
+Environment variables are sometimes used to control experimental features or advanced options
+
+## `EnableGoCliScan`
+
+If the environment variable `EnableGoCliScan` is set, to any value, the Go detector uses [`go mod graph`][1] to discover Go dependencies.
+If the environment variable is not set, we fall back to parsing `go.mod` and `go.sum` ourselves.
+
+## `PyPiMaxCacheEntries`
+
+The environment variable `PyPiMaxCacheEntries` is used to control the size of the in-memory LRU cache that caches responses from PyPi.
+The default value is 128.
+
+[1]: https://go.dev/ref/mod#go-mod-graph