From e11b1988bd7e1d474db024a1a9a44940b95a3f4b Mon Sep 17 00:00:00 2001
From: Matthew Holt <mholt@users.noreply.github.com>
Date: Thu, 16 Jul 2020 16:07:50 -0600
Subject: [PATCH] readme: Add env var docs

---
 README.md | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/README.md b/README.md
index ad54f7d..7294959 100644
--- a/README.md
+++ b/README.md
@@ -109,6 +109,14 @@ Versions can be anything compatible with `go get`.
 
 
 
+## Environment variables
+
+Because the subcommands and flags are constrained to benefit rapid plugin prototyping, xcaddy does read some environment variables to take cues for its behavior and/or configuration when there is no room for flags.
+
+- `CADDY_VERSION` sets the version of Caddy to build.
+- `XCADDY_RACE_DETECTOR=1` enables the Go race detector in the build.
+- `XCADDY_SKIP_CLEANUP=1` causes xcaddy to leave build artifacts on disk after exiting.
+
 
 ---