From d87c905c0601918093ffa50d1536cb5704a95190 Mon Sep 17 00:00:00 2001
From: Brad Warren <bmw@users.noreply.github.com>
Date: Tue, 5 Nov 2019 17:11:23 -0800
Subject: [PATCH] Add back Python 3.4 support (#7510) (#7511)

* Revert "Deprecation warnings for Python 3.4 (#7378)"

This reverts commit 6fcdfb0e5006be85500fad67a5a67b47befedb2a.

* Revert "Migrate certbot-auto users on CentOS 6 to Python 3.6 (#7268)"

This reverts commit e19b2e04c75b6df4e3f8a455700aa95fca79bcc3.

* add changelog entry

* keep mona in authors

(cherry picked from commit 9b848b1d65783000a13ef3f94ac5fe0e8c3879e7)
---
 .travis.yml                                   |   3 -
 CHANGELOG.md                                  |   9 +
 acme/acme/__init__.py                         |   7 -
 certbot/main.py                               |   4 -
 ...{Dockerfile.redhat6 => Dockerfile.centos6} |  21 +-
 letsencrypt-auto-source/letsencrypt-auto      | 212 +++++-------------
 .../letsencrypt-auto.template                 | 106 +++------
 .../pieces/bootstrappers/rpm_common_base.sh   |  24 +-
 .../pieces/bootstrappers/rpm_python3.sh       |   7 +
 .../bootstrappers/rpm_python3_legacy.sh       |  75 -------
 .../tests/centos6_tests.sh                    | 147 ++++--------
 .../tests/oraclelinux6_tests.sh               |  85 -------
 .../letstest/scripts/test_leauto_upgrades.sh  |   2 -
 tests/letstest/scripts/test_sdists.sh         |  13 --
 tox.ini                                       |  12 +-
 15 files changed, 177 insertions(+), 550 deletions(-)
 rename letsencrypt-auto-source/{Dockerfile.redhat6 => Dockerfile.centos6} (50%)
 delete mode 100644 letsencrypt-auto-source/pieces/bootstrappers/rpm_python3_legacy.sh
 delete mode 100644 letsencrypt-auto-source/tests/oraclelinux6_tests.sh

diff --git a/.travis.yml b/.travis.yml
index a1172f086..22391c84f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -234,9 +234,6 @@ matrix:
     - sudo: required
       env: TOXENV=le_auto_centos6
       services: docker
-    - sudo: required
-      env: TOXENV=le_auto_oraclelinux6
-      services: docker
       <<: *extended-test-suite
     - sudo: required
       env: TOXENV=docker_dev
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a0b6eaaa9..6c18de0d7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,15 @@
 
 Certbot adheres to [Semantic Versioning](https://semver.org/).
 
+## 0.40.1 - master
+
+### Changed
+
+* Added back support for Python 3.4 to Certbot components and certbot-auto due
+  to a bug when requiring Python 2.7 or 3.5+ on RHEL 6 based systems.
+
+More details about these changes can be found on our GitHub repo.
+
 ## 0.40.0 - 2019-11-05
 
 ### Added
diff --git a/acme/acme/__init__.py b/acme/acme/__init__.py
index e68ebd765..7439712b0 100644
--- a/acme/acme/__init__.py
+++ b/acme/acme/__init__.py
@@ -48,10 +48,3 @@ class _TLSSNI01DeprecationModule(object):
 
     def __dir__(self):  # pragma: no cover
         return ['_module'] + dir(self._module)
-
-if sys.version_info[:2] == (3, 4):
-    warnings.warn(
-            "Python 3.4 support will be dropped in the next release of "
-            "acme. Please upgrade your Python version.",
-            PendingDeprecationWarning,
-    ) # pragma: no cover
diff --git a/certbot/main.py b/certbot/main.py
index 30d0f1d94..fc91aca5f 100644
--- a/certbot/main.py
+++ b/certbot/main.py
@@ -1368,10 +1368,6 @@ def main(cli_args=None):
         if config.func != plugins_cmd:
             raise
 
-    if sys.version_info[:2] == (3, 4):
-        logger.warning("Python 3.4 support will be dropped in the next release "
-                    "of Certbot - please upgrade your Python version.")
-
     set_displayer(config)
 
     # Reporter
diff --git a/letsencrypt-auto-source/Dockerfile.redhat6 b/letsencrypt-auto-source/Dockerfile.centos6
similarity index 50%
rename from letsencrypt-auto-source/Dockerfile.redhat6
rename to letsencrypt-auto-source/Dockerfile.centos6
index d5cdc0458..09aa52dcd 100644
--- a/letsencrypt-auto-source/Dockerfile.redhat6
+++ b/letsencrypt-auto-source/Dockerfile.centos6
@@ -1,13 +1,9 @@
 # For running tests, build a docker image with a passwordless sudo and a trust
 # store we can manipulate.
 
-ARG REDHAT_DIST_FLAVOR
-FROM ${REDHAT_DIST_FLAVOR}:6
+FROM centos:6
 
-ARG REDHAT_DIST_FLAVOR
-
-RUN curl -O https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm \
- && rpm -ivh epel-release-latest-6.noarch.rpm
+RUN yum install -y epel-release
 
 # Install pip and sudo:
 RUN yum install -y python-pip sudo
@@ -31,18 +27,11 @@ RUN mkdir -p /home/lea/certbot
 COPY ./tests/certs/ca/my-root-ca.crt.pem /usr/local/share/ca-certificates/
 RUN update-ca-trust
 
-# Copy current letsencrypt-auto:
+# Copy code:
 COPY . /home/lea/certbot/letsencrypt-auto-source
 
-# Fetch previous letsencrypt-auto that was installing python 3.4
-RUN curl https://raw.githubusercontent.com/certbot/certbot/v0.38.0/letsencrypt-auto-source/letsencrypt-auto \
-    -o /home/lea/certbot/letsencrypt-auto-source/letsencrypt-auto_py_34 \
- && chmod +x /home/lea/certbot/letsencrypt-auto-source/letsencrypt-auto_py_34
-
-RUN cp /home/lea/certbot/letsencrypt-auto-source/tests/${REDHAT_DIST_FLAVOR}6_tests.sh /home/lea/certbot/letsencrypt-auto-source/tests/redhat6_tests.sh \
- && chmod +x /home/lea/certbot/letsencrypt-auto-source/tests/redhat6_tests.sh
-
 USER lea
 WORKDIR /home/lea
 
-CMD ["sudo", "certbot/letsencrypt-auto-source/tests/redhat6_tests.sh"]
+RUN sudo chmod +x certbot/letsencrypt-auto-source/tests/centos6_tests.sh
+CMD sudo certbot/letsencrypt-auto-source/tests/centos6_tests.sh
diff --git a/letsencrypt-auto-source/letsencrypt-auto b/letsencrypt-auto-source/letsencrypt-auto
index 5df7f5f30..b2ab0e5dd 100755
--- a/letsencrypt-auto-source/letsencrypt-auto
+++ b/letsencrypt-auto-source/letsencrypt-auto
@@ -256,28 +256,20 @@ DeprecationBootstrap() {
   fi
 }
 
-MIN_PYTHON_2_VERSION="2.7"
-MIN_PYVER2=$(echo "$MIN_PYTHON_2_VERSION" | sed 's/\.//')
-MIN_PYTHON_3_VERSION="3.5"
-MIN_PYVER3=$(echo "$MIN_PYTHON_3_VERSION" | sed 's/\.//')
+MIN_PYTHON_VERSION="2.7"
+MIN_PYVER=$(echo "$MIN_PYTHON_VERSION" | sed 's/\.//')
 # Sets LE_PYTHON to Python version string and PYVER to the first two
-# digits of the python version.
-# MIN_PYVER and MIN_PYTHON_VERSION are also set by this function, and their
-# values depend on if we try to use Python 3 or Python 2.
+# digits of the python version
 DeterminePythonVersion() {
   # Arguments: "NOCRASH" if we shouldn't crash if we don't find a good python
   #
   # If no Python is found, PYVER is set to 0.
   if [ "$USE_PYTHON_3" = 1 ]; then
-    MIN_PYVER=$MIN_PYVER3
-    MIN_PYTHON_VERSION=$MIN_PYTHON_3_VERSION
     for LE_PYTHON in "$LE_PYTHON" python3; do
       # Break (while keeping the LE_PYTHON value) if found.
       $EXISTS "$LE_PYTHON" > /dev/null && break
     done
   else
-    MIN_PYVER=$MIN_PYVER2
-    MIN_PYTHON_VERSION=$MIN_PYTHON_2_VERSION
     for LE_PYTHON in "$LE_PYTHON" python2.7 python27 python2 python; do
       # Break (while keeping the LE_PYTHON value) if found.
       $EXISTS "$LE_PYTHON" > /dev/null && break
@@ -293,7 +285,7 @@ DeterminePythonVersion() {
     fi
   fi
 
-  PYVER=$("$LE_PYTHON" -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//')
+  PYVER=`"$LE_PYTHON" -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//'`
   if [ "$PYVER" -lt "$MIN_PYVER" ]; then
     if [ "$1" != "NOCRASH" ]; then
       error "You have an ancient version of Python entombed in your operating system..."
@@ -376,9 +368,7 @@ BootstrapDebCommon() {
 
 # Sets TOOL to the name of the package manager
 # Sets appropriate values for YES_FLAG and QUIET_FLAG based on $ASSUME_YES and $QUIET_FLAG.
-# Note: this function is called both while selecting the bootstrap scripts and
-# during the actual bootstrap. Some things like prompting to user can be done in the latter
-# case, but not in the former one.
+# Enables EPEL if applicable and possible.
 InitializeRPMCommonBase() {
   if type dnf 2>/dev/null
   then
@@ -398,6 +388,26 @@ InitializeRPMCommonBase() {
   if [ "$QUIET" = 1 ]; then
     QUIET_FLAG='--quiet'
   fi
+
+  if ! $TOOL list *virtualenv >/dev/null 2>&1; then
+    echo "To use Certbot, packages from the EPEL repository need to be installed."
+    if ! $TOOL list epel-release >/dev/null 2>&1; then
+      error "Enable the EPEL repository and try running Certbot again."
+      exit 1
+    fi
+    if [ "$ASSUME_YES" = 1 ]; then
+      /bin/echo -n "Enabling the EPEL repository in 3 seconds..."
+      sleep 1s
+      /bin/echo -ne "\e[0K\rEnabling the EPEL repository in 2 seconds..."
+      sleep 1s
+      /bin/echo -e "\e[0K\rEnabling the EPEL repository in 1 second..."
+      sleep 1s
+    fi
+    if ! $TOOL install $YES_FLAG $QUIET_FLAG epel-release; then
+      error "Could not enable EPEL. Aborting bootstrap!"
+      exit 1
+    fi
+  fi
 }
 
 BootstrapRpmCommonBase() {
@@ -478,88 +488,13 @@ BootstrapRpmCommon() {
   BootstrapRpmCommonBase "$python_pkgs"
 }
 
-# If new packages are installed by BootstrapRpmPython3 below, this version
-# number must be increased.
-BOOTSTRAP_RPM_PYTHON3_LEGACY_VERSION=1
-
-# Checks if rh-python36 can be installed.
-Python36SclIsAvailable() {
-  InitializeRPMCommonBase >/dev/null 2>&1;
-
-  if "${TOOL}" list rh-python36 >/dev/null 2>&1; then
-    return 0
-  fi
-  if "${TOOL}" list centos-release-scl >/dev/null 2>&1; then
-    return 0
-  fi
-  return 1
-}
-
-# Try to enable rh-python36 from SCL if it is necessary and possible.
-EnablePython36SCL() {
-  if "$EXISTS" python3.6 > /dev/null 2> /dev/null; then
-      return 0
-  fi
-  if ! scl --list 2>/dev/null | grep -q rh-python36; then
-      return 0
-  fi
-  set +e
-  . scl_source enable rh-python36
-  set -e
-}
-
-# This bootstrap concerns old RedHat-based distributions that do not ship by default
-# with Python 2.7, but only Python 2.6. We bootstrap them by enabling SCL and installing
-# Python 3.6. Some of these distributions are: CentOS/RHEL/OL/SL 6.
-BootstrapRpmPython3Legacy() {
-  # Tested with:
-  #   - CentOS 6
-
-  InitializeRPMCommonBase
-
-  if ! "${TOOL}" list rh-python36 >/dev/null 2>&1; then
-    echo "To use Certbot on this operating system, packages from the SCL repository need to be installed."
-    if ! "${TOOL}" list centos-release-scl >/dev/null 2>&1; then
-      error "Enable the SCL repository and try running Certbot again."
-      exit 1
-    fi
-    if [ "${ASSUME_YES}" = 1 ]; then
-      /bin/echo -n "Enabling the SCL repository in 3 seconds... (Press Ctrl-C to cancel)"
-      sleep 1s
-      /bin/echo -ne "\e[0K\rEnabling the SCL repository in 2 seconds... (Press Ctrl-C to cancel)"
-      sleep 1s
-      /bin/echo -e "\e[0K\rEnabling the SCL repository in 1 second... (Press Ctrl-C to cancel)"
-      sleep 1s
-    fi
-    if ! "${TOOL}" install "${YES_FLAG}" "${QUIET_FLAG}" centos-release-scl; then
-      error "Could not enable SCL. Aborting bootstrap!"
-      exit 1
-    fi
-  fi
-
-  # CentOS 6 must use rh-python36 from SCL
-  if "${TOOL}" list rh-python36 >/dev/null 2>&1; then
-    python_pkgs="rh-python36-python
-      rh-python36-python-virtualenv
-      rh-python36-python-devel
-    "
-  else
-    error "No supported Python package available to install. Aborting bootstrap!"
-    exit 1
-  fi
-
-  BootstrapRpmCommonBase "${python_pkgs}"
-
-  # Enable SCL rh-python36 after bootstrapping.
-  EnablePython36SCL
-}
-
 # If new packages are installed by BootstrapRpmPython3 below, this version
 # number must be increased.
 BOOTSTRAP_RPM_PYTHON3_VERSION=1
 
 BootstrapRpmPython3() {
   # Tested with:
+  #   - CentOS 6
   #   - Fedora 29
 
   InitializeRPMCommonBase
@@ -570,6 +505,12 @@ BootstrapRpmPython3() {
       python3-virtualenv
       python3-devel
     "
+  # EPEL uses python34
+  elif $TOOL list python34 >/dev/null 2>&1; then
+    python_pkgs="python34
+      python34-devel
+      python34-tools
+    "
   else
     error "No supported Python package available to install. Aborting bootstrap!"
     exit 1
@@ -828,50 +769,31 @@ elif [ -f /etc/redhat-release ]; then
      RPM_DIST_VERSION=0
   fi
 
-  # Handle legacy RPM distributions
-  if [ "$PYVER" -eq 26 ]; then
-    # Check if an automated bootstrap can be achieved on this system.
-    if ! Python36SclIsAvailable; then
-      INTERACTIVE_BOOTSTRAP=1
-    fi
+  # Starting to Fedora 29, python2 is on a deprecation path. Let's move to python3 then.
+  # RHEL 8 also uses python3 by default.
+  if [ "$RPM_DIST_NAME" = "fedora" -a "$RPM_DIST_VERSION" -ge 29 -o "$PYVER" -eq 26 ]; then
+    RPM_USE_PYTHON_3=1
+  elif [ "$RPM_DIST_NAME" = "rhel" -a "$RPM_DIST_VERSION" -ge 8 ]; then
+    RPM_USE_PYTHON_3=1
+  elif [ "$RPM_DIST_NAME" = "centos" -a "$RPM_DIST_VERSION" -ge 8 ]; then
+    RPM_USE_PYTHON_3=1
+  else
+    RPM_USE_PYTHON_3=0
+  fi
 
+  if [ "$RPM_USE_PYTHON_3" = 1 ]; then
     Bootstrap() {
-      BootstrapMessage "Legacy RedHat-based OSes that will use Python3"
-      BootstrapRpmPython3Legacy
+      BootstrapMessage "RedHat-based OSes that will use Python3"
+      BootstrapRpmPython3
     }
     USE_PYTHON_3=1
-    BOOTSTRAP_VERSION="BootstrapRpmPython3Legacy $BOOTSTRAP_RPM_PYTHON3_LEGACY_VERSION"
-
-    # Try now to enable SCL rh-python36 for systems already bootstrapped
-    # NB: EnablePython36SCL has been defined along with BootstrapRpmPython3Legacy in certbot-auto
-    EnablePython36SCL
+    BOOTSTRAP_VERSION="BootstrapRpmPython3 $BOOTSTRAP_RPM_PYTHON3_VERSION"
   else
-    # Starting to Fedora 29, python2 is on a deprecation path. Let's move to python3 then.
-    # RHEL 8 also uses python3 by default.
-    if [ "$RPM_DIST_NAME" = "fedora" -a "$RPM_DIST_VERSION" -ge 29 ]; then
-      RPM_USE_PYTHON_3=1
-    elif [ "$RPM_DIST_NAME" = "rhel" -a "$RPM_DIST_VERSION" -ge 8 ]; then
-      RPM_USE_PYTHON_3=1
-    elif [ "$RPM_DIST_NAME" = "centos" -a "$RPM_DIST_VERSION" -ge 8 ]; then
-      RPM_USE_PYTHON_3=1
-    else
-      RPM_USE_PYTHON_3=0
-    fi
-
-    if [ "$RPM_USE_PYTHON_3" = 1 ]; then
-      Bootstrap() {
-        BootstrapMessage "RedHat-based OSes that will use Python3"
-        BootstrapRpmPython3
-      }
-      USE_PYTHON_3=1
-      BOOTSTRAP_VERSION="BootstrapRpmPython3 $BOOTSTRAP_RPM_PYTHON3_VERSION"
-    else
-      Bootstrap() {
-        BootstrapMessage "RedHat-based OSes"
-        BootstrapRpmCommon
-      }
-      BOOTSTRAP_VERSION="BootstrapRpmCommon $BOOTSTRAP_RPM_COMMON_VERSION"
-    fi
+    Bootstrap() {
+      BootstrapMessage "RedHat-based OSes"
+      BootstrapRpmCommon
+    }
+    BOOTSTRAP_VERSION="BootstrapRpmCommon $BOOTSTRAP_RPM_COMMON_VERSION"
   fi
 
   LE_PYTHON="$prev_le_python"
@@ -1156,15 +1078,8 @@ if [ "$1" = "--le-auto-phase2" ]; then
     # If the selected Bootstrap function isn't a noop and it differs from the
     # previously used version
     if [ -n "$BOOTSTRAP_VERSION" -a "$BOOTSTRAP_VERSION" != "$PREV_BOOTSTRAP_VERSION" ]; then
-      # Check if we can rebootstrap without manual user intervention: this requires that
-      # certbot-auto is in non-interactive mode AND selected bootstrap does not claim to
-      # require a manual user intervention.
-      if [ "$NONINTERACTIVE" = 1 -a "$INTERACTIVE_BOOTSTRAP" != 1 ]; then
-        CAN_REBOOTSTRAP=1
-      fi
-      # Check if rebootstrap can be done non-interactively and current shell is non-interactive
-      # (true if stdin and stdout are not attached to a terminal).
-      if [ \( "$CAN_REBOOTSTRAP" = 1 \) -o \( \( -t 0 \) -a \( -t 1 \) \) ]; then
+      # if non-interactive mode or stdin and stdout are connected to a terminal
+      if [ \( "$NONINTERACTIVE" = 1 \) -o \( \( -t 0 \) -a \( -t 1 \) \) ]; then
         if [ -d "$VENV_PATH" ]; then
           rm -rf "$VENV_PATH"
         fi
@@ -1175,21 +1090,12 @@ if [ "$1" = "--le-auto-phase2" ]; then
           ln -s "$VENV_PATH" "$OLD_VENV_PATH"
         fi
         RerunWithArgs "$@"
-      # Otherwise bootstrap needs to be done manually by the user.
       else
-        # If it is because bootstrapping is interactive, --non-interactive will be of no use.
-        if [ "$INTERACTIVE_BOOTSTRAP" = 1 ]; then
-          error "Skipping upgrade because new OS dependencies may need to be installed."
-          error "This requires manual user intervention: please run this script again manually."
-        # If this is because of the environment (eg. non interactive shell without
-        # --non-interactive flag set), help the user in that direction.
-        else
-          error "Skipping upgrade because new OS dependencies may need to be installed."
-          error
-          error "To upgrade to a newer version, please run this script again manually so you can"
-          error "approve changes or with --non-interactive on the command line to automatically"
-          error "install any required packages."
-        fi
+        error "Skipping upgrade because new OS dependencies may need to be installed."
+        error
+        error "To upgrade to a newer version, please run this script again manually so you can"
+        error "approve changes or with --non-interactive on the command line to automatically"
+        error "install any required packages."
         # Set INSTALLED_VERSION to be the same so we don't update the venv
         INSTALLED_VERSION="$LE_AUTO_VERSION"
         # Continue to use OLD_VENV_PATH if the new venv doesn't exist
diff --git a/letsencrypt-auto-source/letsencrypt-auto.template b/letsencrypt-auto-source/letsencrypt-auto.template
index bc4b92092..31c5bb134 100755
--- a/letsencrypt-auto-source/letsencrypt-auto.template
+++ b/letsencrypt-auto-source/letsencrypt-auto.template
@@ -256,28 +256,20 @@ DeprecationBootstrap() {
   fi
 }
 
-MIN_PYTHON_2_VERSION="2.7"
-MIN_PYVER2=$(echo "$MIN_PYTHON_2_VERSION" | sed 's/\.//')
-MIN_PYTHON_3_VERSION="3.5"
-MIN_PYVER3=$(echo "$MIN_PYTHON_3_VERSION" | sed 's/\.//')
+MIN_PYTHON_VERSION="2.7"
+MIN_PYVER=$(echo "$MIN_PYTHON_VERSION" | sed 's/\.//')
 # Sets LE_PYTHON to Python version string and PYVER to the first two
-# digits of the python version.
-# MIN_PYVER and MIN_PYTHON_VERSION are also set by this function, and their
-# values depend on if we try to use Python 3 or Python 2.
+# digits of the python version
 DeterminePythonVersion() {
   # Arguments: "NOCRASH" if we shouldn't crash if we don't find a good python
   #
   # If no Python is found, PYVER is set to 0.
   if [ "$USE_PYTHON_3" = 1 ]; then
-    MIN_PYVER=$MIN_PYVER3
-    MIN_PYTHON_VERSION=$MIN_PYTHON_3_VERSION
     for LE_PYTHON in "$LE_PYTHON" python3; do
       # Break (while keeping the LE_PYTHON value) if found.
       $EXISTS "$LE_PYTHON" > /dev/null && break
     done
   else
-    MIN_PYVER=$MIN_PYVER2
-    MIN_PYTHON_VERSION=$MIN_PYTHON_2_VERSION
     for LE_PYTHON in "$LE_PYTHON" python2.7 python27 python2 python; do
       # Break (while keeping the LE_PYTHON value) if found.
       $EXISTS "$LE_PYTHON" > /dev/null && break
@@ -293,7 +285,7 @@ DeterminePythonVersion() {
     fi
   fi
 
-  PYVER=$("$LE_PYTHON" -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//')
+  PYVER=`"$LE_PYTHON" -V 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//'`
   if [ "$PYVER" -lt "$MIN_PYVER" ]; then
     if [ "$1" != "NOCRASH" ]; then
       error "You have an ancient version of Python entombed in your operating system..."
@@ -306,7 +298,6 @@ DeterminePythonVersion() {
 {{ bootstrappers/deb_common.sh }}
 {{ bootstrappers/rpm_common_base.sh }}
 {{ bootstrappers/rpm_common.sh }}
-{{ bootstrappers/rpm_python3_legacy.sh }}
 {{ bootstrappers/rpm_python3.sh }}
 {{ bootstrappers/suse_common.sh }}
 {{ bootstrappers/arch_common.sh }}
@@ -353,50 +344,31 @@ elif [ -f /etc/redhat-release ]; then
      RPM_DIST_VERSION=0
   fi
 
-  # Handle legacy RPM distributions
-  if [ "$PYVER" -eq 26 ]; then
-    # Check if an automated bootstrap can be achieved on this system.
-    if ! Python36SclIsAvailable; then
-      INTERACTIVE_BOOTSTRAP=1
-    fi
+  # Starting to Fedora 29, python2 is on a deprecation path. Let's move to python3 then.
+  # RHEL 8 also uses python3 by default.
+  if [ "$RPM_DIST_NAME" = "fedora" -a "$RPM_DIST_VERSION" -ge 29 -o "$PYVER" -eq 26 ]; then
+    RPM_USE_PYTHON_3=1
+  elif [ "$RPM_DIST_NAME" = "rhel" -a "$RPM_DIST_VERSION" -ge 8 ]; then
+    RPM_USE_PYTHON_3=1
+  elif [ "$RPM_DIST_NAME" = "centos" -a "$RPM_DIST_VERSION" -ge 8 ]; then
+    RPM_USE_PYTHON_3=1
+  else
+    RPM_USE_PYTHON_3=0
+  fi
 
+  if [ "$RPM_USE_PYTHON_3" = 1 ]; then
     Bootstrap() {
-      BootstrapMessage "Legacy RedHat-based OSes that will use Python3"
-      BootstrapRpmPython3Legacy
+      BootstrapMessage "RedHat-based OSes that will use Python3"
+      BootstrapRpmPython3
     }
     USE_PYTHON_3=1
-    BOOTSTRAP_VERSION="BootstrapRpmPython3Legacy $BOOTSTRAP_RPM_PYTHON3_LEGACY_VERSION"
-
-    # Try now to enable SCL rh-python36 for systems already bootstrapped
-    # NB: EnablePython36SCL has been defined along with BootstrapRpmPython3Legacy in certbot-auto
-    EnablePython36SCL
+    BOOTSTRAP_VERSION="BootstrapRpmPython3 $BOOTSTRAP_RPM_PYTHON3_VERSION"
   else
-    # Starting to Fedora 29, python2 is on a deprecation path. Let's move to python3 then.
-    # RHEL 8 also uses python3 by default.
-    if [ "$RPM_DIST_NAME" = "fedora" -a "$RPM_DIST_VERSION" -ge 29 ]; then
-      RPM_USE_PYTHON_3=1
-    elif [ "$RPM_DIST_NAME" = "rhel" -a "$RPM_DIST_VERSION" -ge 8 ]; then
-      RPM_USE_PYTHON_3=1
-    elif [ "$RPM_DIST_NAME" = "centos" -a "$RPM_DIST_VERSION" -ge 8 ]; then
-      RPM_USE_PYTHON_3=1
-    else
-      RPM_USE_PYTHON_3=0
-    fi
-
-    if [ "$RPM_USE_PYTHON_3" = 1 ]; then
-      Bootstrap() {
-        BootstrapMessage "RedHat-based OSes that will use Python3"
-        BootstrapRpmPython3
-      }
-      USE_PYTHON_3=1
-      BOOTSTRAP_VERSION="BootstrapRpmPython3 $BOOTSTRAP_RPM_PYTHON3_VERSION"
-    else
-      Bootstrap() {
-        BootstrapMessage "RedHat-based OSes"
-        BootstrapRpmCommon
-      }
-      BOOTSTRAP_VERSION="BootstrapRpmCommon $BOOTSTRAP_RPM_COMMON_VERSION"
-    fi
+    Bootstrap() {
+      BootstrapMessage "RedHat-based OSes"
+      BootstrapRpmCommon
+    }
+    BOOTSTRAP_VERSION="BootstrapRpmCommon $BOOTSTRAP_RPM_COMMON_VERSION"
   fi
 
   LE_PYTHON="$prev_le_python"
@@ -573,15 +545,8 @@ if [ "$1" = "--le-auto-phase2" ]; then
     # If the selected Bootstrap function isn't a noop and it differs from the
     # previously used version
     if [ -n "$BOOTSTRAP_VERSION" -a "$BOOTSTRAP_VERSION" != "$PREV_BOOTSTRAP_VERSION" ]; then
-      # Check if we can rebootstrap without manual user intervention: this requires that
-      # certbot-auto is in non-interactive mode AND selected bootstrap does not claim to
-      # require a manual user intervention.
-      if [ "$NONINTERACTIVE" = 1 -a "$INTERACTIVE_BOOTSTRAP" != 1 ]; then
-        CAN_REBOOTSTRAP=1
-      fi
-      # Check if rebootstrap can be done non-interactively and current shell is non-interactive
-      # (true if stdin and stdout are not attached to a terminal).
-      if [ \( "$CAN_REBOOTSTRAP" = 1 \) -o \( \( -t 0 \) -a \( -t 1 \) \) ]; then
+      # if non-interactive mode or stdin and stdout are connected to a terminal
+      if [ \( "$NONINTERACTIVE" = 1 \) -o \( \( -t 0 \) -a \( -t 1 \) \) ]; then
         if [ -d "$VENV_PATH" ]; then
           rm -rf "$VENV_PATH"
         fi
@@ -592,21 +557,12 @@ if [ "$1" = "--le-auto-phase2" ]; then
           ln -s "$VENV_PATH" "$OLD_VENV_PATH"
         fi
         RerunWithArgs "$@"
-      # Otherwise bootstrap needs to be done manually by the user.
       else
-        # If it is because bootstrapping is interactive, --non-interactive will be of no use.
-        if [ "$INTERACTIVE_BOOTSTRAP" = 1 ]; then
-          error "Skipping upgrade because new OS dependencies may need to be installed."
-          error "This requires manual user intervention: please run this script again manually."
-        # If this is because of the environment (eg. non interactive shell without
-        # --non-interactive flag set), help the user in that direction.
-        else
-          error "Skipping upgrade because new OS dependencies may need to be installed."
-          error
-          error "To upgrade to a newer version, please run this script again manually so you can"
-          error "approve changes or with --non-interactive on the command line to automatically"
-          error "install any required packages."
-        fi
+        error "Skipping upgrade because new OS dependencies may need to be installed."
+        error
+        error "To upgrade to a newer version, please run this script again manually so you can"
+        error "approve changes or with --non-interactive on the command line to automatically"
+        error "install any required packages."
         # Set INSTALLED_VERSION to be the same so we don't update the venv
         INSTALLED_VERSION="$LE_AUTO_VERSION"
         # Continue to use OLD_VENV_PATH if the new venv doesn't exist
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/rpm_common_base.sh b/letsencrypt-auto-source/pieces/bootstrappers/rpm_common_base.sh
index 2b00b199b..326ad8b3f 100644
--- a/letsencrypt-auto-source/pieces/bootstrappers/rpm_common_base.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/rpm_common_base.sh
@@ -3,9 +3,7 @@
 
 # Sets TOOL to the name of the package manager
 # Sets appropriate values for YES_FLAG and QUIET_FLAG based on $ASSUME_YES and $QUIET_FLAG.
-# Note: this function is called both while selecting the bootstrap scripts and
-# during the actual bootstrap. Some things like prompting to user can be done in the latter
-# case, but not in the former one.
+# Enables EPEL if applicable and possible.
 InitializeRPMCommonBase() {
   if type dnf 2>/dev/null
   then
@@ -25,6 +23,26 @@ InitializeRPMCommonBase() {
   if [ "$QUIET" = 1 ]; then
     QUIET_FLAG='--quiet'
   fi
+
+  if ! $TOOL list *virtualenv >/dev/null 2>&1; then
+    echo "To use Certbot, packages from the EPEL repository need to be installed."
+    if ! $TOOL list epel-release >/dev/null 2>&1; then
+      error "Enable the EPEL repository and try running Certbot again."
+      exit 1
+    fi
+    if [ "$ASSUME_YES" = 1 ]; then
+      /bin/echo -n "Enabling the EPEL repository in 3 seconds..."
+      sleep 1s
+      /bin/echo -ne "\e[0K\rEnabling the EPEL repository in 2 seconds..."
+      sleep 1s
+      /bin/echo -e "\e[0K\rEnabling the EPEL repository in 1 second..."
+      sleep 1s
+    fi
+    if ! $TOOL install $YES_FLAG $QUIET_FLAG epel-release; then
+      error "Could not enable EPEL. Aborting bootstrap!"
+      exit 1
+    fi
+  fi
 }
 
 BootstrapRpmCommonBase() {
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/rpm_python3.sh b/letsencrypt-auto-source/pieces/bootstrappers/rpm_python3.sh
index ac0553db5..f33b07ca9 100644
--- a/letsencrypt-auto-source/pieces/bootstrappers/rpm_python3.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/rpm_python3.sh
@@ -4,6 +4,7 @@ BOOTSTRAP_RPM_PYTHON3_VERSION=1
 
 BootstrapRpmPython3() {
   # Tested with:
+  #   - CentOS 6
   #   - Fedora 29
 
   InitializeRPMCommonBase
@@ -14,6 +15,12 @@ BootstrapRpmPython3() {
       python3-virtualenv
       python3-devel
     "
+  # EPEL uses python34
+  elif $TOOL list python34 >/dev/null 2>&1; then
+    python_pkgs="python34
+      python34-devel
+      python34-tools
+    "
   else
     error "No supported Python package available to install. Aborting bootstrap!"
     exit 1
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/rpm_python3_legacy.sh b/letsencrypt-auto-source/pieces/bootstrappers/rpm_python3_legacy.sh
deleted file mode 100644
index 0935c1b94..000000000
--- a/letsencrypt-auto-source/pieces/bootstrappers/rpm_python3_legacy.sh
+++ /dev/null
@@ -1,75 +0,0 @@
-# If new packages are installed by BootstrapRpmPython3 below, this version
-# number must be increased.
-BOOTSTRAP_RPM_PYTHON3_LEGACY_VERSION=1
-
-# Checks if rh-python36 can be installed.
-Python36SclIsAvailable() {
-  InitializeRPMCommonBase >/dev/null 2>&1;
-
-  if "${TOOL}" list rh-python36 >/dev/null 2>&1; then
-    return 0
-  fi
-  if "${TOOL}" list centos-release-scl >/dev/null 2>&1; then
-    return 0
-  fi
-  return 1
-}
-
-# Try to enable rh-python36 from SCL if it is necessary and possible.
-EnablePython36SCL() {
-  if "$EXISTS" python3.6 > /dev/null 2> /dev/null; then
-      return 0
-  fi
-  if ! scl --list 2>/dev/null | grep -q rh-python36; then
-      return 0
-  fi
-  set +e
-  . scl_source enable rh-python36
-  set -e
-}
-
-# This bootstrap concerns old RedHat-based distributions that do not ship by default
-# with Python 2.7, but only Python 2.6. We bootstrap them by enabling SCL and installing
-# Python 3.6. Some of these distributions are: CentOS/RHEL/OL/SL 6.
-BootstrapRpmPython3Legacy() {
-  # Tested with:
-  #   - CentOS 6
-
-  InitializeRPMCommonBase
-
-  if ! "${TOOL}" list rh-python36 >/dev/null 2>&1; then
-    echo "To use Certbot on this operating system, packages from the SCL repository need to be installed."
-    if ! "${TOOL}" list centos-release-scl >/dev/null 2>&1; then
-      error "Enable the SCL repository and try running Certbot again."
-      exit 1
-    fi
-    if [ "${ASSUME_YES}" = 1 ]; then
-      /bin/echo -n "Enabling the SCL repository in 3 seconds... (Press Ctrl-C to cancel)"
-      sleep 1s
-      /bin/echo -ne "\e[0K\rEnabling the SCL repository in 2 seconds... (Press Ctrl-C to cancel)"
-      sleep 1s
-      /bin/echo -e "\e[0K\rEnabling the SCL repository in 1 second... (Press Ctrl-C to cancel)"
-      sleep 1s
-    fi
-    if ! "${TOOL}" install "${YES_FLAG}" "${QUIET_FLAG}" centos-release-scl; then
-      error "Could not enable SCL. Aborting bootstrap!"
-      exit 1
-    fi
-  fi
-
-  # CentOS 6 must use rh-python36 from SCL
-  if "${TOOL}" list rh-python36 >/dev/null 2>&1; then
-    python_pkgs="rh-python36-python
-      rh-python36-python-virtualenv
-      rh-python36-python-devel
-    "
-  else
-    error "No supported Python package available to install. Aborting bootstrap!"
-    exit 1
-  fi
-
-  BootstrapRpmCommonBase "${python_pkgs}"
-
-  # Enable SCL rh-python36 after bootstrapping.
-  EnablePython36SCL
-}
diff --git a/letsencrypt-auto-source/tests/centos6_tests.sh b/letsencrypt-auto-source/tests/centos6_tests.sh
index c15cd80ec..2c6dcf734 100644
--- a/letsencrypt-auto-source/tests/centos6_tests.sh
+++ b/letsencrypt-auto-source/tests/centos6_tests.sh
@@ -1,140 +1,81 @@
 #!/bin/bash
 # Start by making sure your system is up-to-date:
-yum update -y >/dev/null
-yum install -y centos-release-scl >/dev/null
-yum install -y python27 >/dev/null 2>/dev/null
+yum update -y > /dev/null
+yum install -y centos-release-scl > /dev/null
+yum install -y python27 > /dev/null 2> /dev/null
 
-LE_AUTO_PY_34="certbot/letsencrypt-auto-source/letsencrypt-auto_py_34"
 LE_AUTO="certbot/letsencrypt-auto-source/letsencrypt-auto"
 
-# Last version of certbot-auto that was bootstraping Python 3.4 for CentOS 6 users
-INITIAL_CERTBOT_VERSION_PY34="certbot 0.38.0"
-
 # we're going to modify env variables, so do this in a subshell
 (
-  . scl_source enable python27
+source /opt/rh/python27/enable
 
-  # ensure python 3 isn't installed
-  python3 --version >/dev/null 2>/dev/null
-  RESULT=$?
-  if [ $RESULT -eq 0 ]; then
-    echo "ERROR: Python3 is already installed."
-    exit 1
-  fi
+# ensure python 3 isn't installed
+python3 --version 2> /dev/null
+RESULT=$?
+if [ $RESULT -eq 0 ]; then
+  error "Python3 is already installed."
+  exit 1
+fi
 
-  # ensure python2.7 is available
-  python2.7 --version >/dev/null 2>/dev/null
-  RESULT=$?
-  if [ $RESULT -ne 0 ]; then
-    echo "ERROR: Python2.7 is not available."
-    exit 1
-  fi
+# ensure python2.7 is available
+python2.7 --version 2> /dev/null
+RESULT=$?
+if [ $RESULT -ne 0 ]; then
+  error "Python3 is not available."
+  exit 1
+fi
 
-  # bootstrap, but don't install python 3.
-  "$LE_AUTO" --no-self-upgrade -n >/dev/null 2>/dev/null
+# bootstrap, but don't install python 3.
+"$LE_AUTO" --no-self-upgrade -n > /dev/null 2> /dev/null
 
-  # ensure python 3 isn't installed
-  python3 --version >/dev/null 2>/dev/null
-  RESULT=$?
-  if [ $RESULT -eq 0 ]; then
-    echo "ERROR: letsencrypt-auto installed Python3 even though Python2.7 is present."
-    exit 1
-  fi
+# ensure python 3 isn't installed
+python3 --version 2> /dev/null
+RESULT=$?
+if [ $RESULT -eq 0 ]; then
+  error "letsencrypt-auto installed Python3 even though Python2.7 is present."
+  exit 1
+fi
 
-  echo "PASSED: Did not upgrade to Python3 when Python2.7 is present."
+echo ""
+echo "PASSED: Did not upgrade to Python3 when Python2.7 is present."
 )
 
 # ensure python2.7 isn't available
-python2.7 --version >/dev/null 2>/dev/null
+python2.7 --version 2> /dev/null
 RESULT=$?
 if [ $RESULT -eq 0 ]; then
-  error "ERROR: Python2.7 is still available."
+  error "Python2.7 is still available."
   exit 1
 fi
 
 # Skip self upgrade due to Python 3 not being available.
 if ! "$LE_AUTO" 2>&1 | grep -q "WARNING: couldn't find Python"; then
-  echo "ERROR: Python upgrade failure warning not printed!"
+  echo "Python upgrade failure warning not printed!"
   exit 1
 fi
 
-# bootstrap from the old letsencrypt-auto, this time installing python3.4
-"$LE_AUTO_PY_34" --no-self-upgrade -n >/dev/null 2>/dev/null
+# bootstrap, this time installing python3
+"$LE_AUTO" --no-self-upgrade -n > /dev/null 2> /dev/null
 
-# ensure python 3.4 is installed
-python3.4 --version >/dev/null 2>/dev/null
+# ensure python 3 is installed
+python3 --version > /dev/null
 RESULT=$?
 if [ $RESULT -ne 0 ]; then
-  echo "ERROR: letsencrypt-auto failed to install Python3.4 using letsencrypt-auto < 0.37.0 when only Python2.6 is present."
+  error "letsencrypt-auto failed to install Python3 when only Python2.6 is present."
   exit 1
 fi
 
-echo "PASSED: Successfully upgraded to Python3.4 using letsencrypt-auto < 0.37.0 when only Python2.6 is present."
+echo "PASSED: Successfully upgraded to Python3 when only Python2.6 is present."
+echo ""
 
-# As "certbot-auto" (so without implicit --non-interactive flag set), check that the script
-# refuses to install SCL Python 3.6 when run in a non interactive shell (simulated here
-# using | tee /dev/null) if --non-interactive flag is not provided.
-cp "$LE_AUTO" /tmp/certbot-auto
-# NB: Readline has an issue on all Python versions for CentOS 6, making `certbot --version`
-# output an unprintable ASCII character on a new line at the end.
-# So we take the second last line of the output.
-version=$(/tmp/certbot-auto --version 2>/dev/null | tee /dev/null | tail -2 | head -1)
-
-if [ "$version" != "$INITIAL_CERTBOT_VERSION_PY34" ]; then
-  echo "ERROR: certbot-auto upgraded certbot in a non-interactive shell with --non-interactive flag not set."
+export VENV_PATH=$(mktemp -d)
+"$LE_AUTO" -n --no-bootstrap --no-self-upgrade --version >/dev/null 2>&1
+if [ "$($VENV_PATH/bin/python -V 2>&1 | cut -d" " -f2 | cut -d. -f1)" != 3 ]; then
+  echo "Python 3 wasn't used with --no-bootstrap!"
   exit 1
 fi
-
-echo "PASSED: certbot-auto did not upgrade certbot in a non-interactive shell with --non-interactive flag not set."
-
-if [ -f /opt/rh/rh-python36/enable ]; then
-  echo "ERROR: certbot-auto installed Python3.6 in a non-interactive shell with --non-interactive flag not set."
-  exit 1
-fi
-
-echo "PASSED: certbot-auto did not install Python3.6 in a non-interactive shell with --non-interactive flag not set."
-
-# now bootstrap from current letsencrypt-auto, that will install python3.6 from SCL
-"$LE_AUTO" --no-self-upgrade -n >/dev/null 2>/dev/null
-
-# Following test is exectued in a subshell, to not leak any environment variable
-(
-  # enable SCL rh-python36
-  . scl_source enable rh-python36
-
-  # ensure python 3.6 is installed
-  python3.6 --version >/dev/null 2>/dev/null
-  RESULT=$?
-  if [ $RESULT -ne 0 ]; then
-    echo "ERROR: letsencrypt-auto failed to install Python3.6 using current letsencrypt-auto when only Python2.6/Python3.4 are present."
-    exit 1
-  fi
-
-  echo "PASSED: Successfully upgraded to Python3.6 using current letsencrypt-auto when only Python2.6/Python3.4 are present."
-)
-
-# Following test is exectued in a subshell, to not leak any environment variable
-(
-  export VENV_PATH=$(mktemp -d)
-  "$LE_AUTO" -n --no-bootstrap --no-self-upgrade --version >/dev/null 2>&1
-  if [ "$($VENV_PATH/bin/python -V 2>&1 | cut -d" " -f2 | cut -d. -f1-2)" != "3.6" ]; then
-    echo "ERROR: Python 3.6 wasn't used with --no-bootstrap!"
-    exit 1
-  fi
-)
-
-# Following test is exectued in a subshell, to not leak any environment variable
-(
-  # enable SCL rh-python36
-  . scl_source enable rh-python36
-
-  # ensure everything works fine with certbot-auto bootstrap when python 3.6 is already enabled
-  export VENV_PATH=$(mktemp -d)
-  if ! "$LE_AUTO" --no-self-upgrade -n --version >/dev/null 2>/dev/null; then
-    echo "ERROR: Certbot-auto broke when Python 3.6 SCL is already enabled."
-    exit 1
-  fi
-)
+unset VENV_PATH
 
 # test using python3
 pytest -v -s certbot/letsencrypt-auto-source/tests
diff --git a/letsencrypt-auto-source/tests/oraclelinux6_tests.sh b/letsencrypt-auto-source/tests/oraclelinux6_tests.sh
deleted file mode 100644
index f3fd952f3..000000000
--- a/letsencrypt-auto-source/tests/oraclelinux6_tests.sh
+++ /dev/null
@@ -1,85 +0,0 @@
-#!/bin/bash
-set -eo pipefail
-# Start by making sure your system is up-to-date:
-yum update -y >/dev/null
-
-LE_AUTO_PY_34="certbot/letsencrypt-auto-source/letsencrypt-auto_py_34"
-LE_AUTO="certbot/letsencrypt-auto-source/letsencrypt-auto"
-
-# Apply installation instructions from official documentation:
-# https://certbot.eff.org/lets-encrypt/centosrhel6-other
-cp "$LE_AUTO" /usr/local/bin/certbot-auto
-chown root /usr/local/bin/certbot-auto
-chmod 0755 /usr/local/bin/certbot-auto
-LE_AUTO=/usr/local/bin/certbot-auto
-
-# Last version of certbot-auto that was bootstraping Python 3.4 for CentOS 6 users
-INITIAL_CERTBOT_VERSION_PY34="certbot 0.38.0"
-
-# Check bootstrap from current certbot-auto will fail, because SCL is not enabled.
-set +o pipefail
-if ! "$LE_AUTO" -n 2>&1 | grep -q "Enable the SCL repository and try running Certbot again."; then
-  echo "ERROR: Bootstrap was not aborted although SCL was not installed!"
-  exit 1
-fi
-set -o pipefail
-
-echo "PASSED: Bootstrap was aborted since SCL was not installed."
-
-# Bootstrap from the old letsencrypt-auto, Python 3.4 will be installed from EPEL.
-"$LE_AUTO_PY_34" --no-self-upgrade -n --install-only >/dev/null 2>/dev/null
-
-# Ensure Python 3.4 is installed
-if ! command -v python3.4 &>/dev/null; then
-  echo "ERROR: old letsencrypt-auto failed to install Python3.4 using letsencrypt-auto < 0.37.0 when only Python2.6 is present."
-  exit 1
-fi
-
-echo "PASSED: Bootstrap from old letsencrypt-auto succeeded and installed Python 3.4"
-
-# Expect certbot-auto to skip rebootstrapping with a warning since SCL is not installed.
-if ! "$LE_AUTO" --non-interactive --version 2>&1 | grep -q "This requires manual user intervention"; then
-  echo "FAILED: Script certbot-auto did not print a warning about needing manual intervention!"
-  exit 1
-fi
-
-echo "PASSED: Script certbot-auto did not rebootstrap."
-
-# NB: Readline has an issue on all Python versions for OL 6, making `certbot --version`
-# output an unprintable ASCII character on a new line at the end.
-# So we take the second last line of the output.
-version=$($LE_AUTO --version 2>/dev/null | tail -2 | head -1)
-
-if [ "$version" != "$INITIAL_CERTBOT_VERSION_PY34" ]; then
-  echo "ERROR: Script certbot-auto upgraded certbot in a non-interactive shell while SCL was not enabled."
-  exit 1
-fi
-
-echo "PASSED: Script certbot-auto did not upgrade certbot but started it successfully while SCL was not enabled."
-
-# Enable SCL
-yum install -y oracle-softwarecollection-release-el6 >/dev/null
-
-# Expect certbot-auto to bootstrap successfully since SCL is available.
-"$LE_AUTO" -n --version &>/dev/null
-
-if [ "$(/opt/eff.org/certbot/venv/bin/python -V 2>&1 | cut -d" " -f2 | cut -d. -f1-2)" != "3.6" ]; then
-  echo "ERROR: Script certbot-auto failed to bootstrap and install Python 3.6 while SCL is available."
-  exit 1
-fi
-
-if ! /opt/eff.org/certbot/venv/bin/certbot --version > /dev/null 2> /dev/null; then
-  echo "ERROR: Script certbot-auto did not install certbot correctly while SCL is enabled."
-  exit 1
-fi
-
-echo "PASSED: Script certbot-auto correctly bootstraped Certbot using rh-python36 when SCL is available."
-
-# Expect certbot-auto will be totally silent now that everything has been correctly boostraped.
-OUTPUT_LEN=$("$LE_AUTO" --install-only --no-self-upgrade --quiet 2>&1 | wc -c)
-if [ "$OUTPUT_LEN" != 0 ]; then
-    echo certbot-auto produced unexpected output!
-    exit 1
-fi
-
-echo "PASSED: Script certbot-auto did not print anything in quiet mode."
diff --git a/tests/letstest/scripts/test_leauto_upgrades.sh b/tests/letstest/scripts/test_leauto_upgrades.sh
index fc7632793..541f54f6b 100755
--- a/tests/letstest/scripts/test_leauto_upgrades.sh
+++ b/tests/letstest/scripts/test_leauto_upgrades.sh
@@ -117,8 +117,6 @@ if ! diff letsencrypt-auto letsencrypt-auto-source/letsencrypt-auto ; then
 fi
 
 if [ "$RUN_RHEL6_TESTS" = 1 ]; then
-    # Add the SCL python release to PATH in order to resolve python3 command
-    PATH="/opt/rh/rh-python36/root/usr/bin:$PATH"
     if ! command -v python3; then
         echo "Python3 wasn't properly installed"
         exit 1
diff --git a/tests/letstest/scripts/test_sdists.sh b/tests/letstest/scripts/test_sdists.sh
index c8ce9fe7f..347589e04 100755
--- a/tests/letstest/scripts/test_sdists.sh
+++ b/tests/letstest/scripts/test_sdists.sh
@@ -1,21 +1,8 @@
 #!/bin/sh -xe
 
 cd letsencrypt
-
-# 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
-    # RHEL/CentOS 6 will need a special treatment, so we need to detect that environment
-    RUN_RHEL6_TESTS=1
-fi
-
 letsencrypt-auto-source/letsencrypt-auto --install-only -n --debug
 
-if [ "$RUN_RHEL6_TESTS" = 1 ]; then
-  # Enable the SCL Python 3.6 installed by letsencrypt-auto bootstrap
-  PATH="/opt/rh/rh-python36/root/usr/bin:$PATH"
-fi
-
 PLUGINS="certbot-apache certbot-nginx"
 PYTHON_MAJOR_VERSION=$(/opt/eff.org/certbot/venv/bin/python --version 2>&1 | cut -d" " -f 2 | cut -d. -f1)
 TEMP_DIR=$(mktemp -d)
diff --git a/tox.ini b/tox.ini
index 952204a9e..04715cc2f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -206,17 +206,7 @@ passenv = DOCKER_*
 # At the moment, this tests under Python 2.6 only, as only that version is
 # readily available on the CentOS 6 Docker image.
 commands =
-    docker build -f letsencrypt-auto-source/Dockerfile.redhat6 --build-arg REDHAT_DIST_FLAVOR=centos -t lea letsencrypt-auto-source
-    docker run --rm -t -i lea
-whitelist_externals =
-    docker
-passenv = DOCKER_*
-
-[testenv:le_auto_oraclelinux6]
-# At the moment, this tests under Python 2.6 only, as only that version is
-# readily available on the Oracle Linux 6 Docker image.
-commands =
-    docker build -f letsencrypt-auto-source/Dockerfile.redhat6 --build-arg REDHAT_DIST_FLAVOR=oraclelinux -t lea letsencrypt-auto-source
+    docker build -f letsencrypt-auto-source/Dockerfile.centos6 -t lea letsencrypt-auto-source
     docker run --rm -t -i lea
 whitelist_externals =
     docker