[autotest] Add lucifer setup docs

BUG=None
TEST=None

Change-Id: I9499d6971f3b8b614e9b54662c8c3f94a55c3691
Reviewed-on: https://chromium-review.googlesource.com/1023039
Commit-Ready: Allen Li <ayatane@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Allen Li <ayatane@chromium.org>
diff --git a/README.md b/README.md
index 34b6cd7..392f98b 100644
--- a/README.md
+++ b/README.md
@@ -64,3 +64,7 @@
 
 You need to run `utils/build_externals.py` to set up the dependencies
 for pre-upload hook tests.
+
+## Setting up Lucifer
+
+[Setting up Lucifer](docs/lucifer-setup.md)
diff --git a/docs/lucifer-setup.md b/docs/lucifer-setup.md
new file mode 100644
index 0000000..6dfaede
--- /dev/null
+++ b/docs/lucifer-setup.md
@@ -0,0 +1,18 @@
+# Setting up Lucifer
+
+Install [depot_tools].
+
+[depot_tools]: https://commondatastorage.googleapis.com/chrome-infra-docs/flat/depot_tools/docs/html/depot_tools_tutorial.html#_setting_up
+
+Get the Lucifer binaries:
+
+    binary_dir=~/lucifer
+    mkdir -p "$binary_dir"
+    cipd install -root "$binary_dir" chromiumos/infra/lucifer prod
+
+Add the path to `shadow_config.ini`:
+
+    cat <<EOF >>/usr/local/autotest/shadow_config.ini
+    [LUCIFER]
+    binaries_path: $binary_dir/usr/bin
+    EOF