From a754a90940f95059a7e754bb97ae86d95a9886b1 Mon Sep 17 00:00:00 2001
From: Brad Warren <bmw@users.noreply.github.com>
Date: Mon, 6 May 2019 16:50:03 -0700
Subject: [PATCH] Fix test_leauto_upgrades.sh on CentOS 6. (#7037)

---
 tests/letstest/scripts/test_leauto_upgrades.sh | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/tests/letstest/scripts/test_leauto_upgrades.sh b/tests/letstest/scripts/test_leauto_upgrades.sh
index d5133ba38..8cc1748ed 100755
--- a/tests/letstest/scripts/test_leauto_upgrades.sh
+++ b/tests/letstest/scripts/test_leauto_upgrades.sh
@@ -15,8 +15,17 @@ if ! command -v git ; then
         exit 1
     fi
 fi
-# 0.33.x is the oldest version of letsencrypt-auto that works on Fedora 29+.
-INITIAL_VERSION="0.33.1"
+# If we're on a RHEL 6 based system, we can be confident Python is already
+# installed because the package manager is written in Python.
+if command -v python && [ $(python -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//') -eq 26 ]; then
+    # 0.20.0 is the latest version of letsencrypt-auto that doesn't install
+    # Python 3 on RHEL 6.
+    INITIAL_VERSION="0.20.0"
+    RUN_PYTHON3_TESTS=1
+else
+    # 0.33.x is the oldest version of letsencrypt-auto that works on Fedora 29+.
+    INITIAL_VERSION="0.33.1"
+fi
 git checkout -f "v$INITIAL_VERSION" letsencrypt-auto
 if ! ./letsencrypt-auto -v --debug --version --no-self-upgrade 2>&1 | tail -n1 | grep "^certbot $INITIAL_VERSION$" ; then
     echo initial installation appeared to fail
@@ -63,8 +72,7 @@ iQIDAQAB
 -----END PUBLIC KEY-----
 "
 
-if [ $(python -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//') -eq 26 ]; then
-    RUN_PYTHON3_TESTS=1
+if [ "$RUN_PYTHON3_TESTS" = 1 ]; then
     if command -v python3; then
         echo "Didn't expect Python 3 to be installed!"
         exit 1