From 56db211367d171aed5ee9aee1eccd87041e14de8 Mon Sep 17 00:00:00 2001
From: Brad Warren <bmw@users.noreply.github.com>
Date: Mon, 21 Aug 2017 12:23:09 -0700
Subject: [PATCH] Change certbot-auto's installation path to /opt (#4970)

* Update comment about root usage.

* run all of certbot-auto as root

* remove other $SUDO uses from template

* remove $SUDO usage from bootstrappers

* default venv path = /opt/eff.org/certbot/venv

* Create symlinks from old default venvs

* Delete old venv path when it exists.

Also, quote expansion of paths.

* fix typo

* Separate venv_dir and le_auto_path

* Deduplicate code with test_dirs()

* Ignore cleanup errors.

This is caused by subdirectories being owned by root.

* Split test into test_phase2_upgrade.

* Rename test_dirs to temp_paths for clarity.

* Check both venvs before bootstrapping again.

* Use OLD_VENV_PATH/bin

* Preserve environment with sudo.

* Remove "esp. under sudo" comment.

* Export *VENV_PATH.

* Change check for OLD_VENV installation.

This approach better handles manually set VENV_PATH values.

* Remove SUDO_ENV.

* Print message before requesting root privileges.

* Make a function for selecting root auth method.

* Address @erikrose's feedback.
---
 letsencrypt-auto-source/letsencrypt-auto      | 179 ++++++++++--------
 .../letsencrypt-auto.template                 | 129 +++++++------
 .../pieces/bootstrappers/arch_common.sh       |   6 +-
 .../pieces/bootstrappers/deb_common.sh        |  10 +-
 .../pieces/bootstrappers/free_bsd.sh          |   2 +-
 .../pieces/bootstrappers/gentoo_common.sh     |   6 +-
 .../pieces/bootstrappers/mac.sh               |   6 +-
 .../pieces/bootstrappers/mageia_common.sh     |   4 +-
 .../pieces/bootstrappers/rpm_common.sh        |  14 +-
 .../pieces/bootstrappers/suse_common.sh       |   2 +-
 letsencrypt-auto-source/tests/auto_test.py    |  79 ++++----
 11 files changed, 241 insertions(+), 196 deletions(-)

diff --git a/letsencrypt-auto-source/letsencrypt-auto b/letsencrypt-auto-source/letsencrypt-auto
index 39f8728e8..8ce3342be 100755
--- a/letsencrypt-auto-source/letsencrypt-auto
+++ b/letsencrypt-auto-source/letsencrypt-auto
@@ -23,9 +23,11 @@ fi
 if [ -z "$XDG_DATA_HOME" ]; then
   XDG_DATA_HOME=~/.local/share
 fi
-VENV_NAME="letsencrypt"
 if [ -z "$VENV_PATH" ]; then
-  VENV_PATH="$XDG_DATA_HOME/$VENV_NAME"
+  # We export these values so they are preserved properly if this script is
+  # rerun with sudo/su where $HOME/$XDG_DATA_HOME may have a different value.
+  export OLD_VENV_PATH="$XDG_DATA_HOME/letsencrypt"
+  export VENV_PATH="/opt/eff.org/certbot/venv"
 fi
 VENV_BIN="$VENV_PATH/bin"
 LE_AUTO_VERSION="0.18.0.dev0"
@@ -49,6 +51,7 @@ Help for certbot itself cannot be provided until it is installed.
                                             implies --non-interactive
 
 All arguments are accepted and forwarded to the Certbot client when run."
+export CERTBOT_AUTO="$0"
 
 for arg in "$@" ; do
   case "$arg" in
@@ -119,16 +122,18 @@ else
   exit 1
 fi
 
-# certbot-auto needs root access to bootstrap OS dependencies, and
-# certbot itself needs root access for almost all modes of operation
-# The "normal" case is that sudo is used for the steps that need root, but
-# this script *can* be run as root (not recommended), or fall back to using
-# `su`. Auto-detection can be overridden by explicitly setting the
-# environment variable LE_AUTO_SUDO to 'sudo', 'sudo_su' or '' as used below.
+# Certbot itself needs root access for almost all modes of operation.
+# certbot-auto needs root access to bootstrap OS dependencies and install
+# Certbot at a protected path so it can be safely run as root. To accomplish
+# this, this script will attempt to run itself as root if it doesn't have the
+# necessary privileges by using `sudo` or falling back to `su` if it is not
+# available. The mechanism used to obtain root access can be set explicitly by
+# setting the environment variable LE_AUTO_SUDO to 'sudo', 'su', 'su_sudo',
+# 'SuSudo', or '' as used below.
 
 # Because the parameters in `su -c` has to be a string,
 # we need to properly escape it.
-su_sudo() {
+SuSudo() {
   args=""
   # This `while` loop iterates over all parameters given to this function.
   # For each parameter, all `'` will be replace by `'"'"'`, and the escaped string
@@ -147,34 +152,47 @@ su_sudo() {
   su root -c "$args"
 }
 
-SUDO_ENV=""
-export CERTBOT_AUTO="$0"
-if [ -n "${LE_AUTO_SUDO+x}" ]; then
-  case "$LE_AUTO_SUDO" in
-    su_sudo|su)
-      SUDO=su_sudo
-      ;;
-    sudo)
-      SUDO=sudo
-      SUDO_ENV="CERTBOT_AUTO=$0"
-      ;;
-    '') ;; # Nothing to do for plain root method.
-    *)
-      error "Error: unknown root authorization mechanism '$LE_AUTO_SUDO'."
-      exit 1
-  esac
-  say "Using preset root authorization mechanism '$LE_AUTO_SUDO'."
-else
-  if test "`id -u`" -ne "0" ; then
-    if $EXISTS sudo 1>/dev/null 2>&1; then
-      SUDO=sudo
-      SUDO_ENV="CERTBOT_AUTO=$0"
-    else
-      say \"sudo\" is not available, will use \"su\" for installation steps...
-      SUDO=su_sudo
-    fi
+# Sets the environment variable SUDO to be the name of the program or function
+# to call to get root access. If this script already has root privleges, SUDO
+# is set to an empty string. The value in SUDO should be run with the command
+# to called with root privileges as arguments.
+SetRootAuthMechanism() {
+  SUDO=""
+  if [ -n "${LE_AUTO_SUDO+x}" ]; then
+    case "$LE_AUTO_SUDO" in
+      SuSudo|su_sudo|su)
+        SUDO=SuSudo
+        ;;
+      sudo)
+        SUDO="sudo -E"
+        ;;
+      '') ;; # Nothing to do for plain root method.
+      *)
+        error "Error: unknown root authorization mechanism '$LE_AUTO_SUDO'."
+        exit 1
+    esac
+    say "Using preset root authorization mechanism '$LE_AUTO_SUDO'."
   else
-    SUDO=
+    if test "`id -u`" -ne "0" ; then
+      if $EXISTS sudo 1>/dev/null 2>&1; then
+        SUDO="sudo -E"
+      else
+        say \"sudo\" is not available, will use \"su\" for installation steps...
+        SUDO=SuSudo
+      fi
+    fi
+  fi
+}
+
+if [ "$1" = "--cb-auto-has-root" ]; then
+  shift 1
+elif [ "$1" != "--le-auto-phase2" ]; then
+  # if $1 is --le-auto-phase2, we've executed this branch before
+  SetRootAuthMechanism
+  if [ -n "$SUDO" ]; then
+    echo "Requesting to rerun $0 with root privileges..."
+    $SUDO "$0" --cb-auto-has-root "$@"
+    exit 0
   fi
 fi
 
@@ -261,7 +279,7 @@ BootstrapDebCommon() {
     QUIET_FLAG='-qq'
   fi
 
-  $SUDO apt-get $QUIET_FLAG update || error apt-get update hit problems but continuing anyway...
+  apt-get $QUIET_FLAG update || error apt-get update hit problems but continuing anyway...
 
   # virtualenv binary can be found in different packages depending on
   # distro version (#346)
@@ -311,13 +329,13 @@ BootstrapDebCommon() {
           esac
         fi
         if [ "$add_backports" = 1 ]; then
-          $SUDO sh -c "echo $BACKPORT_SOURCELINE >> /etc/apt/sources.list.d/$BACKPORT_NAME.list"
-          $SUDO apt-get $QUIET_FLAG update
+          sh -c "echo $BACKPORT_SOURCELINE >> /etc/apt/sources.list.d/$BACKPORT_NAME.list"
+          apt-get $QUIET_FLAG update
         fi
       fi
     fi
     if [ "$add_backports" != 0 ]; then
-      $SUDO apt-get install $QUIET_FLAG $YES_FLAG --no-install-recommends -t "$BACKPORT_NAME" $augeas_pkg
+      apt-get install $QUIET_FLAG $YES_FLAG --no-install-recommends -t "$BACKPORT_NAME" $augeas_pkg
       augeas_pkg=
     fi
   }
@@ -336,7 +354,7 @@ BootstrapDebCommon() {
     # XXX add a case for ubuntu PPAs
   fi
 
-  $SUDO apt-get install $QUIET_FLAG $YES_FLAG --no-install-recommends \
+  apt-get install $QUIET_FLAG $YES_FLAG --no-install-recommends \
     python \
     python-dev \
     $virtualenv \
@@ -380,9 +398,9 @@ BootstrapRpmCommon() {
     QUIET_FLAG='--quiet'
   fi
 
-  if ! $SUDO $tool list *virtualenv >/dev/null 2>&1; then
+  if ! $tool list *virtualenv >/dev/null 2>&1; then
     echo "To use Certbot, packages from the EPEL repository need to be installed."
-    if ! $SUDO $tool list epel-release >/dev/null 2>&1; then
+    if ! $tool list epel-release >/dev/null 2>&1; then
       error "Enable the EPEL repository and try running Certbot again."
       exit 1
     fi
@@ -394,7 +412,7 @@ BootstrapRpmCommon() {
       /bin/echo -e "\e[0K\rEnabling the EPEL repository in 1 seconds..."
       sleep 1s
     fi
-    if ! $SUDO $tool install $yes_flag $QUIET_FLAG epel-release; then
+    if ! $tool install $yes_flag $QUIET_FLAG epel-release; then
       error "Could not enable EPEL. Aborting bootstrap!"
       exit 1
     fi
@@ -411,7 +429,7 @@ BootstrapRpmCommon() {
   "
 
   # Most RPM distros use the "python" or "python-" naming convention.  Let's try that first.
-  if $SUDO $tool list python >/dev/null 2>&1; then
+  if $tool list python >/dev/null 2>&1; then
     pkgs="$pkgs
       python
       python-devel
@@ -421,7 +439,7 @@ BootstrapRpmCommon() {
     "
   # Fedora 26 starts to use the prefix python2 for python2 based packages.
   # this elseif is theoretically for any Fedora over version 26:
-  elif $SUDO $tool list python2 >/dev/null 2>&1; then
+  elif $tool list python2 >/dev/null 2>&1; then
     pkgs="$pkgs
       python2
       python2-libs
@@ -443,13 +461,13 @@ BootstrapRpmCommon() {
     "
   fi
 
-  if $SUDO $tool list installed "httpd" >/dev/null 2>&1; then
+  if $tool list installed "httpd" >/dev/null 2>&1; then
     pkgs="$pkgs
       mod_ssl
     "
   fi
 
-  if ! $SUDO $tool install $yes_flag $QUIET_FLAG $pkgs; then
+  if ! $tool install $yes_flag $QUIET_FLAG $pkgs; then
     error "Could not install OS dependencies. Aborting bootstrap!"
     exit 1
   fi
@@ -467,7 +485,7 @@ BootstrapSuseCommon() {
     QUIET_FLAG='-qq'
   fi
 
-  $SUDO zypper $QUIET_FLAG $zypper_flags in $install_flags \
+  zypper $QUIET_FLAG $zypper_flags in $install_flags \
     python \
     python-devel \
     python-virtualenv \
@@ -498,7 +516,7 @@ BootstrapArchCommon() {
   "
 
   # pacman -T exits with 127 if there are missing dependencies
-  missing=$($SUDO pacman -T $deps) || true
+  missing=$(pacman -T $deps) || true
 
   if [ "$ASSUME_YES" = 1 ]; then
     noconfirm="--noconfirm"
@@ -506,9 +524,9 @@ BootstrapArchCommon() {
 
   if [ "$missing" ]; then
     if [ "$QUIET" = 1 ]; then
-      $SUDO pacman -S --needed $missing $noconfirm > /dev/null
+      pacman -S --needed $missing $noconfirm > /dev/null
     else
-      $SUDO pacman -S --needed $missing $noconfirm
+      pacman -S --needed $missing $noconfirm
     fi
   fi
 }
@@ -530,13 +548,13 @@ BootstrapGentooCommon() {
 
   case "$PACKAGE_MANAGER" in
     (paludis)
-      $SUDO cave resolve --preserve-world --keep-targets if-possible $PACKAGES -x
+      cave resolve --preserve-world --keep-targets if-possible $PACKAGES -x
       ;;
     (pkgcore)
-      $SUDO pmerge --noreplace --oneshot $ASK_OPTION $PACKAGES
+      pmerge --noreplace --oneshot $ASK_OPTION $PACKAGES
       ;;
     (portage|*)
-      $SUDO emerge --noreplace --oneshot $ASK_OPTION $PACKAGES
+      emerge --noreplace --oneshot $ASK_OPTION $PACKAGES
       ;;
   esac
 }
@@ -546,7 +564,7 @@ BootstrapFreeBsd() {
     QUIET_FLAG="--quiet"
   fi
 
-  $SUDO pkg install -Ay $QUIET_FLAG \
+  pkg install -Ay $QUIET_FLAG \
     python \
     py27-virtualenv \
     augeas \
@@ -561,7 +579,7 @@ BootstrapMac() {
   elif hash port 2>/dev/null; then
     say "Using MacPorts to install dependencies..."
     pkgman=port
-    pkgcmd="$SUDO port install"
+    pkgcmd="port install"
   else
     say "No Homebrew/MacPorts; installing Homebrew..."
     ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
@@ -581,8 +599,8 @@ BootstrapMac() {
   # Workaround for _dlopen not finding augeas on macOS
   if [ "$pkgman" = "port" ] && ! [ -e "/usr/local/lib/libaugeas.dylib" ] && [ -e "/opt/local/lib/libaugeas.dylib" ]; then
     say "Applying augeas workaround"
-    $SUDO mkdir -p /usr/local/lib/
-    $SUDO ln -s /opt/local/lib/libaugeas.dylib /usr/local/lib/
+    mkdir -p /usr/local/lib/
+    ln -s /opt/local/lib/libaugeas.dylib /usr/local/lib/
   fi
 
   if ! hash pip 2>/dev/null; then
@@ -608,7 +626,7 @@ BootstrapMageiaCommon() {
     QUIET_FLAG='--quiet'
   fi
 
-  if ! $SUDO urpmi --force $QUIET_FLAG \
+  if ! urpmi --force $QUIET_FLAG \
       python \
       libpython-devel \
       python-virtualenv
@@ -617,7 +635,7 @@ BootstrapMageiaCommon() {
       exit 1
   fi
 
-  if ! $SUDO urpmi --force $QUIET_FLAG \
+  if ! urpmi --force $QUIET_FLAG \
       git \
       gcc \
       python-augeas \
@@ -1144,20 +1162,15 @@ UNLIKELY_EOF
       rm -rf "$VENV_PATH"
       exit 1
     fi
+
+    if [ -d "$OLD_VENV_PATH" -a ! -L "$OLD_VENV_PATH" ]; then
+      rm -rf "$OLD_VENV_PATH"
+      ln -s "$VENV_PATH" "$OLD_VENV_PATH"
+    fi
+
     say "Installation succeeded."
   fi
-  if [ -n "$SUDO" ]; then
-    # SUDO is su wrapper or sudo
-    say "Requesting root privileges to run certbot..."
-    say "  $VENV_BIN/letsencrypt" "$@"
-  fi
-  if [ -z "$SUDO_ENV" ] ; then
-    # SUDO is su wrapper / noop
-    $SUDO "$VENV_BIN/letsencrypt" "$@"
-  else
-    # sudo
-    $SUDO "$SUDO_ENV" "$VENV_BIN/letsencrypt" "$@"
-  fi
+  "$VENV_BIN/letsencrypt" "$@"
 
 else
   # Phase 1: Upgrade certbot-auto if necessary, then self-invoke.
@@ -1168,12 +1181,14 @@ else
   # package). Phase 2 checks the version of the locally installed certbot.
 
   if [ ! -f "$VENV_BIN/letsencrypt" ]; then
-    if [ "$HELP" = 1 ]; then
-      echo "$USAGE"
-      exit 0
+    if [ -z "$OLD_VENV_PATH" -o ! -f "$OLD_VENV_PATH/bin/letsencrypt" ]; then
+      if [ "$HELP" = 1 ]; then
+        echo "$USAGE"
+        exit 0
+      fi
+      # If it looks like we've never bootstrapped before, bootstrap:
+      Bootstrap
     fi
-    # If it looks like we've never bootstrapped before, bootstrap:
-    Bootstrap
   fi
   if [ "$OS_PACKAGES_ONLY" = 1 ]; then
     say "OS packages installed."
@@ -1333,13 +1348,13 @@ UNLIKELY_EOF
       say "Replacing certbot-auto..."
       # Clone permissions with cp. chmod and chown don't have a --reference
       # option on macOS or BSD, and stat -c on Linux is stat -f on macOS and BSD:
-      $SUDO cp -p "$0" "$TEMP_DIR/letsencrypt-auto.permission-clone"
-      $SUDO cp "$TEMP_DIR/letsencrypt-auto" "$TEMP_DIR/letsencrypt-auto.permission-clone"
+      cp -p "$0" "$TEMP_DIR/letsencrypt-auto.permission-clone"
+      cp "$TEMP_DIR/letsencrypt-auto" "$TEMP_DIR/letsencrypt-auto.permission-clone"
       # Using mv rather than cp leaves the old file descriptor pointing to the
       # original copy so the shell can continue to read it unmolested. mv across
       # filesystems is non-atomic, doing `rm dest, cp src dest, rm src`, but the
-      # cp is unlikely to fail (esp. under sudo) if the rm doesn't.
-      $SUDO mv -f "$TEMP_DIR/letsencrypt-auto.permission-clone" "$0"
+      # cp is unlikely to fail if the rm doesn't.
+      mv -f "$TEMP_DIR/letsencrypt-auto.permission-clone" "$0"
     fi  # A newer version is available.
   fi  # Self-upgrading is allowed.
 
diff --git a/letsencrypt-auto-source/letsencrypt-auto.template b/letsencrypt-auto-source/letsencrypt-auto.template
index 284241a82..29aaf1291 100755
--- a/letsencrypt-auto-source/letsencrypt-auto.template
+++ b/letsencrypt-auto-source/letsencrypt-auto.template
@@ -23,9 +23,11 @@ fi
 if [ -z "$XDG_DATA_HOME" ]; then
   XDG_DATA_HOME=~/.local/share
 fi
-VENV_NAME="letsencrypt"
 if [ -z "$VENV_PATH" ]; then
-  VENV_PATH="$XDG_DATA_HOME/$VENV_NAME"
+  # We export these values so they are preserved properly if this script is
+  # rerun with sudo/su where $HOME/$XDG_DATA_HOME may have a different value.
+  export OLD_VENV_PATH="$XDG_DATA_HOME/letsencrypt"
+  export VENV_PATH="/opt/eff.org/certbot/venv"
 fi
 VENV_BIN="$VENV_PATH/bin"
 LE_AUTO_VERSION="{{ LE_AUTO_VERSION }}"
@@ -49,6 +51,7 @@ Help for certbot itself cannot be provided until it is installed.
                                             implies --non-interactive
 
 All arguments are accepted and forwarded to the Certbot client when run."
+export CERTBOT_AUTO="$0"
 
 for arg in "$@" ; do
   case "$arg" in
@@ -119,16 +122,18 @@ else
   exit 1
 fi
 
-# certbot-auto needs root access to bootstrap OS dependencies, and
-# certbot itself needs root access for almost all modes of operation
-# The "normal" case is that sudo is used for the steps that need root, but
-# this script *can* be run as root (not recommended), or fall back to using
-# `su`. Auto-detection can be overridden by explicitly setting the
-# environment variable LE_AUTO_SUDO to 'sudo', 'sudo_su' or '' as used below.
+# Certbot itself needs root access for almost all modes of operation.
+# certbot-auto needs root access to bootstrap OS dependencies and install
+# Certbot at a protected path so it can be safely run as root. To accomplish
+# this, this script will attempt to run itself as root if it doesn't have the
+# necessary privileges by using `sudo` or falling back to `su` if it is not
+# available. The mechanism used to obtain root access can be set explicitly by
+# setting the environment variable LE_AUTO_SUDO to 'sudo', 'su', 'su_sudo',
+# 'SuSudo', or '' as used below.
 
 # Because the parameters in `su -c` has to be a string,
 # we need to properly escape it.
-su_sudo() {
+SuSudo() {
   args=""
   # This `while` loop iterates over all parameters given to this function.
   # For each parameter, all `'` will be replace by `'"'"'`, and the escaped string
@@ -147,34 +152,47 @@ su_sudo() {
   su root -c "$args"
 }
 
-SUDO_ENV=""
-export CERTBOT_AUTO="$0"
-if [ -n "${LE_AUTO_SUDO+x}" ]; then
-  case "$LE_AUTO_SUDO" in
-    su_sudo|su)
-      SUDO=su_sudo
-      ;;
-    sudo)
-      SUDO=sudo
-      SUDO_ENV="CERTBOT_AUTO=$0"
-      ;;
-    '') ;; # Nothing to do for plain root method.
-    *)
-      error "Error: unknown root authorization mechanism '$LE_AUTO_SUDO'."
-      exit 1
-  esac
-  say "Using preset root authorization mechanism '$LE_AUTO_SUDO'."
-else
-  if test "`id -u`" -ne "0" ; then
-    if $EXISTS sudo 1>/dev/null 2>&1; then
-      SUDO=sudo
-      SUDO_ENV="CERTBOT_AUTO=$0"
-    else
-      say \"sudo\" is not available, will use \"su\" for installation steps...
-      SUDO=su_sudo
-    fi
+# Sets the environment variable SUDO to be the name of the program or function
+# to call to get root access. If this script already has root privleges, SUDO
+# is set to an empty string. The value in SUDO should be run with the command
+# to called with root privileges as arguments.
+SetRootAuthMechanism() {
+  SUDO=""
+  if [ -n "${LE_AUTO_SUDO+x}" ]; then
+    case "$LE_AUTO_SUDO" in
+      SuSudo|su_sudo|su)
+        SUDO=SuSudo
+        ;;
+      sudo)
+        SUDO="sudo -E"
+        ;;
+      '') ;; # Nothing to do for plain root method.
+      *)
+        error "Error: unknown root authorization mechanism '$LE_AUTO_SUDO'."
+        exit 1
+    esac
+    say "Using preset root authorization mechanism '$LE_AUTO_SUDO'."
   else
-    SUDO=
+    if test "`id -u`" -ne "0" ; then
+      if $EXISTS sudo 1>/dev/null 2>&1; then
+        SUDO="sudo -E"
+      else
+        say \"sudo\" is not available, will use \"su\" for installation steps...
+        SUDO=SuSudo
+      fi
+    fi
+  fi
+}
+
+if [ "$1" = "--cb-auto-has-root" ]; then
+  shift 1
+elif [ "$1" != "--le-auto-phase2" ]; then
+  # if $1 is --le-auto-phase2, we've executed this branch before
+  SetRootAuthMechanism
+  if [ -n "$SUDO" ]; then
+    echo "Requesting to rerun $0 with root privileges..."
+    $SUDO "$0" --cb-auto-has-root "$@"
+    exit 0
   fi
 fi
 
@@ -385,20 +403,15 @@ UNLIKELY_EOF
       rm -rf "$VENV_PATH"
       exit 1
     fi
+
+    if [ -d "$OLD_VENV_PATH" -a ! -L "$OLD_VENV_PATH" ]; then
+      rm -rf "$OLD_VENV_PATH"
+      ln -s "$VENV_PATH" "$OLD_VENV_PATH"
+    fi
+
     say "Installation succeeded."
   fi
-  if [ -n "$SUDO" ]; then
-    # SUDO is su wrapper or sudo
-    say "Requesting root privileges to run certbot..."
-    say "  $VENV_BIN/letsencrypt" "$@"
-  fi
-  if [ -z "$SUDO_ENV" ] ; then
-    # SUDO is su wrapper / noop
-    $SUDO "$VENV_BIN/letsencrypt" "$@"
-  else
-    # sudo
-    $SUDO "$SUDO_ENV" "$VENV_BIN/letsencrypt" "$@"
-  fi
+  "$VENV_BIN/letsencrypt" "$@"
 
 else
   # Phase 1: Upgrade certbot-auto if necessary, then self-invoke.
@@ -409,12 +422,14 @@ else
   # package). Phase 2 checks the version of the locally installed certbot.
 
   if [ ! -f "$VENV_BIN/letsencrypt" ]; then
-    if [ "$HELP" = 1 ]; then
-      echo "$USAGE"
-      exit 0
+    if [ -z "$OLD_VENV_PATH" -o ! -f "$OLD_VENV_PATH/bin/letsencrypt" ]; then
+      if [ "$HELP" = 1 ]; then
+        echo "$USAGE"
+        exit 0
+      fi
+      # If it looks like we've never bootstrapped before, bootstrap:
+      Bootstrap
     fi
-    # If it looks like we've never bootstrapped before, bootstrap:
-    Bootstrap
   fi
   if [ "$OS_PACKAGES_ONLY" = 1 ]; then
     say "OS packages installed."
@@ -445,13 +460,13 @@ UNLIKELY_EOF
       say "Replacing certbot-auto..."
       # Clone permissions with cp. chmod and chown don't have a --reference
       # option on macOS or BSD, and stat -c on Linux is stat -f on macOS and BSD:
-      $SUDO cp -p "$0" "$TEMP_DIR/letsencrypt-auto.permission-clone"
-      $SUDO cp "$TEMP_DIR/letsencrypt-auto" "$TEMP_DIR/letsencrypt-auto.permission-clone"
+      cp -p "$0" "$TEMP_DIR/letsencrypt-auto.permission-clone"
+      cp "$TEMP_DIR/letsencrypt-auto" "$TEMP_DIR/letsencrypt-auto.permission-clone"
       # Using mv rather than cp leaves the old file descriptor pointing to the
       # original copy so the shell can continue to read it unmolested. mv across
       # filesystems is non-atomic, doing `rm dest, cp src dest, rm src`, but the
-      # cp is unlikely to fail (esp. under sudo) if the rm doesn't.
-      $SUDO mv -f "$TEMP_DIR/letsencrypt-auto.permission-clone" "$0"
+      # cp is unlikely to fail if the rm doesn't.
+      mv -f "$TEMP_DIR/letsencrypt-auto.permission-clone" "$0"
     fi  # A newer version is available.
   fi  # Self-upgrading is allowed.
 
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/arch_common.sh b/letsencrypt-auto-source/pieces/bootstrappers/arch_common.sh
index e9d91fe70..3983bc1d8 100755
--- a/letsencrypt-auto-source/pieces/bootstrappers/arch_common.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/arch_common.sh
@@ -18,7 +18,7 @@ BootstrapArchCommon() {
   "
 
   # pacman -T exits with 127 if there are missing dependencies
-  missing=$($SUDO pacman -T $deps) || true
+  missing=$(pacman -T $deps) || true
 
   if [ "$ASSUME_YES" = 1 ]; then
     noconfirm="--noconfirm"
@@ -26,9 +26,9 @@ BootstrapArchCommon() {
 
   if [ "$missing" ]; then
     if [ "$QUIET" = 1 ]; then
-      $SUDO pacman -S --needed $missing $noconfirm > /dev/null
+      pacman -S --needed $missing $noconfirm > /dev/null
     else
-      $SUDO pacman -S --needed $missing $noconfirm
+      pacman -S --needed $missing $noconfirm
     fi
   fi
 }
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/deb_common.sh b/letsencrypt-auto-source/pieces/bootstrappers/deb_common.sh
index afd279ac2..12aa80d63 100644
--- a/letsencrypt-auto-source/pieces/bootstrappers/deb_common.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/deb_common.sh
@@ -21,7 +21,7 @@ BootstrapDebCommon() {
     QUIET_FLAG='-qq'
   fi
 
-  $SUDO apt-get $QUIET_FLAG update || error apt-get update hit problems but continuing anyway...
+  apt-get $QUIET_FLAG update || error apt-get update hit problems but continuing anyway...
 
   # virtualenv binary can be found in different packages depending on
   # distro version (#346)
@@ -71,13 +71,13 @@ BootstrapDebCommon() {
           esac
         fi
         if [ "$add_backports" = 1 ]; then
-          $SUDO sh -c "echo $BACKPORT_SOURCELINE >> /etc/apt/sources.list.d/$BACKPORT_NAME.list"
-          $SUDO apt-get $QUIET_FLAG update
+          sh -c "echo $BACKPORT_SOURCELINE >> /etc/apt/sources.list.d/$BACKPORT_NAME.list"
+          apt-get $QUIET_FLAG update
         fi
       fi
     fi
     if [ "$add_backports" != 0 ]; then
-      $SUDO apt-get install $QUIET_FLAG $YES_FLAG --no-install-recommends -t "$BACKPORT_NAME" $augeas_pkg
+      apt-get install $QUIET_FLAG $YES_FLAG --no-install-recommends -t "$BACKPORT_NAME" $augeas_pkg
       augeas_pkg=
     fi
   }
@@ -96,7 +96,7 @@ BootstrapDebCommon() {
     # XXX add a case for ubuntu PPAs
   fi
 
-  $SUDO apt-get install $QUIET_FLAG $YES_FLAG --no-install-recommends \
+  apt-get install $QUIET_FLAG $YES_FLAG --no-install-recommends \
     python \
     python-dev \
     $virtualenv \
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/free_bsd.sh b/letsencrypt-auto-source/pieces/bootstrappers/free_bsd.sh
index f1bc00f3b..cfbd2b8b1 100755
--- a/letsencrypt-auto-source/pieces/bootstrappers/free_bsd.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/free_bsd.sh
@@ -3,7 +3,7 @@ BootstrapFreeBsd() {
     QUIET_FLAG="--quiet"
   fi
 
-  $SUDO pkg install -Ay $QUIET_FLAG \
+  pkg install -Ay $QUIET_FLAG \
     python \
     py27-virtualenv \
     augeas \
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/gentoo_common.sh b/letsencrypt-auto-source/pieces/bootstrappers/gentoo_common.sh
index 86a1ec7d6..46543bab9 100755
--- a/letsencrypt-auto-source/pieces/bootstrappers/gentoo_common.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/gentoo_common.sh
@@ -15,13 +15,13 @@ BootstrapGentooCommon() {
 
   case "$PACKAGE_MANAGER" in
     (paludis)
-      $SUDO cave resolve --preserve-world --keep-targets if-possible $PACKAGES -x
+      cave resolve --preserve-world --keep-targets if-possible $PACKAGES -x
       ;;
     (pkgcore)
-      $SUDO pmerge --noreplace --oneshot $ASK_OPTION $PACKAGES
+      pmerge --noreplace --oneshot $ASK_OPTION $PACKAGES
       ;;
     (portage|*)
-      $SUDO emerge --noreplace --oneshot $ASK_OPTION $PACKAGES
+      emerge --noreplace --oneshot $ASK_OPTION $PACKAGES
       ;;
   esac
 }
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/mac.sh b/letsencrypt-auto-source/pieces/bootstrappers/mac.sh
index b88e96999..b9f347f67 100755
--- a/letsencrypt-auto-source/pieces/bootstrappers/mac.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/mac.sh
@@ -6,7 +6,7 @@ BootstrapMac() {
   elif hash port 2>/dev/null; then
     say "Using MacPorts to install dependencies..."
     pkgman=port
-    pkgcmd="$SUDO port install"
+    pkgcmd="port install"
   else
     say "No Homebrew/MacPorts; installing Homebrew..."
     ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
@@ -26,8 +26,8 @@ BootstrapMac() {
   # Workaround for _dlopen not finding augeas on macOS
   if [ "$pkgman" = "port" ] && ! [ -e "/usr/local/lib/libaugeas.dylib" ] && [ -e "/opt/local/lib/libaugeas.dylib" ]; then
     say "Applying augeas workaround"
-    $SUDO mkdir -p /usr/local/lib/
-    $SUDO ln -s /opt/local/lib/libaugeas.dylib /usr/local/lib/
+    mkdir -p /usr/local/lib/
+    ln -s /opt/local/lib/libaugeas.dylib /usr/local/lib/
   fi
 
   if ! hash pip 2>/dev/null; then
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/mageia_common.sh b/letsencrypt-auto-source/pieces/bootstrappers/mageia_common.sh
index 1c76bbcac..c9a540ce1 100644
--- a/letsencrypt-auto-source/pieces/bootstrappers/mageia_common.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/mageia_common.sh
@@ -3,7 +3,7 @@ BootstrapMageiaCommon() {
     QUIET_FLAG='--quiet'
   fi
 
-  if ! $SUDO urpmi --force $QUIET_FLAG \
+  if ! urpmi --force $QUIET_FLAG \
       python \
       libpython-devel \
       python-virtualenv
@@ -12,7 +12,7 @@ BootstrapMageiaCommon() {
       exit 1
   fi
 
-  if ! $SUDO urpmi --force $QUIET_FLAG \
+  if ! urpmi --force $QUIET_FLAG \
       git \
       gcc \
       python-augeas \
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/rpm_common.sh b/letsencrypt-auto-source/pieces/bootstrappers/rpm_common.sh
index 965ee32f3..129684338 100755
--- a/letsencrypt-auto-source/pieces/bootstrappers/rpm_common.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/rpm_common.sh
@@ -24,9 +24,9 @@ BootstrapRpmCommon() {
     QUIET_FLAG='--quiet'
   fi
 
-  if ! $SUDO $tool list *virtualenv >/dev/null 2>&1; then
+  if ! $tool list *virtualenv >/dev/null 2>&1; then
     echo "To use Certbot, packages from the EPEL repository need to be installed."
-    if ! $SUDO $tool list epel-release >/dev/null 2>&1; then
+    if ! $tool list epel-release >/dev/null 2>&1; then
       error "Enable the EPEL repository and try running Certbot again."
       exit 1
     fi
@@ -38,7 +38,7 @@ BootstrapRpmCommon() {
       /bin/echo -e "\e[0K\rEnabling the EPEL repository in 1 seconds..."
       sleep 1s
     fi
-    if ! $SUDO $tool install $yes_flag $QUIET_FLAG epel-release; then
+    if ! $tool install $yes_flag $QUIET_FLAG epel-release; then
       error "Could not enable EPEL. Aborting bootstrap!"
       exit 1
     fi
@@ -55,7 +55,7 @@ BootstrapRpmCommon() {
   "
 
   # Most RPM distros use the "python" or "python-" naming convention.  Let's try that first.
-  if $SUDO $tool list python >/dev/null 2>&1; then
+  if $tool list python >/dev/null 2>&1; then
     pkgs="$pkgs
       python
       python-devel
@@ -65,7 +65,7 @@ BootstrapRpmCommon() {
     "
   # Fedora 26 starts to use the prefix python2 for python2 based packages.
   # this elseif is theoretically for any Fedora over version 26:
-  elif $SUDO $tool list python2 >/dev/null 2>&1; then
+  elif $tool list python2 >/dev/null 2>&1; then
     pkgs="$pkgs
       python2
       python2-libs
@@ -87,13 +87,13 @@ BootstrapRpmCommon() {
     "
   fi
 
-  if $SUDO $tool list installed "httpd" >/dev/null 2>&1; then
+  if $tool list installed "httpd" >/dev/null 2>&1; then
     pkgs="$pkgs
       mod_ssl
     "
   fi
 
-  if ! $SUDO $tool install $yes_flag $QUIET_FLAG $pkgs; then
+  if ! $tool install $yes_flag $QUIET_FLAG $pkgs; then
     error "Could not install OS dependencies. Aborting bootstrap!"
     exit 1
   fi
diff --git a/letsencrypt-auto-source/pieces/bootstrappers/suse_common.sh b/letsencrypt-auto-source/pieces/bootstrappers/suse_common.sh
index e60ca8628..56e7acda3 100755
--- a/letsencrypt-auto-source/pieces/bootstrappers/suse_common.sh
+++ b/letsencrypt-auto-source/pieces/bootstrappers/suse_common.sh
@@ -10,7 +10,7 @@ BootstrapSuseCommon() {
     QUIET_FLAG='-qq'
   fi
 
-  $SUDO zypper $QUIET_FLAG $zypper_flags in $install_flags \
+  zypper $QUIET_FLAG $zypper_flags in $install_flags \
     python \
     python-devel \
     python-virtualenv \
diff --git a/letsencrypt-auto-source/tests/auto_test.py b/letsencrypt-auto-source/tests/auto_test.py
index 6f21c28d5..5c63325ee 100644
--- a/letsencrypt-auto-source/tests/auto_test.py
+++ b/letsencrypt-auto-source/tests/auto_test.py
@@ -4,7 +4,7 @@ from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
 from contextlib import contextmanager
 from functools import partial
 from json import dumps
-from os import chmod, environ
+from os import chmod, environ, makedirs
 from os.path import abspath, dirname, exists, join
 import re
 from shutil import copy, rmtree
@@ -118,12 +118,13 @@ LE_AUTO_PATH = join(dirname(tests_dir()), 'letsencrypt-auto')
 
 
 @contextmanager
-def ephemeral_dir():
+def temp_paths():
+    """Creates and deletes paths for letsencrypt-auto and its venv."""
     dir = mkdtemp(prefix='le-test-')
     try:
-        yield dir
+        yield join(dir, 'letsencrypt-auto'), join(dir, 'venv')
     finally:
-        rmtree(dir)
+        rmtree(dir, ignore_errors=True)
 
 
 def out_and_err(command, input=None, shell=False, env=None):
@@ -160,21 +161,20 @@ def signed(content, private_key_name='signing.key'):
     return out
 
 
-def install_le_auto(contents, venv_dir):
+def install_le_auto(contents, install_path):
     """Install some given source code as the letsencrypt-auto script at the
     root level of a virtualenv.
 
     :arg contents: The contents of the built letsencrypt-auto script
-    :arg venv_dir: The path under which to install the script
+    :arg install_path: The path where to install the script
 
     """
-    venv_le_auto_path = join(venv_dir, 'letsencrypt-auto')
-    with open(venv_le_auto_path, 'w') as le_auto:
+    with open(install_path, 'w') as le_auto:
         le_auto.write(contents)
-    chmod(venv_le_auto_path, S_IRUSR | S_IXUSR)
+    chmod(install_path, S_IRUSR | S_IXUSR)
 
 
-def run_le_auto(venv_dir, base_url, **kwargs):
+def run_le_auto(le_auto_path, venv_dir, base_url, **kwargs):
     """Run the prebuilt version of letsencrypt-auto, returning stdout and
     stderr strings.
 
@@ -182,7 +182,7 @@ def run_le_auto(venv_dir, base_url, **kwargs):
 
     """
     env = environ.copy()
-    d = dict(XDG_DATA_HOME=venv_dir,
+    d = dict(VENV_PATH=venv_dir,
              # URL to PyPI-style JSON that tell us the latest released version
              # of LE:
              LE_AUTO_JSON_URL=base_url + 'certbot/json',
@@ -201,7 +201,7 @@ iQIDAQAB
              **kwargs)
     env.update(d)
     return out_and_err(
-        join(venv_dir, 'letsencrypt-auto') + ' --version',
+        le_auto_path + ' --version',
         shell=True,
         env=env)
 
@@ -213,10 +213,12 @@ def set_le_script_version(venv_dir, version):
     print its version.
 
     """
-    with open(join(venv_dir, 'letsencrypt', 'bin', 'letsencrypt'), 'w') as script:
+    letsencrypt_path = join(venv_dir, 'bin', 'letsencrypt')
+    with open(letsencrypt_path, 'w') as script:
         script.write("#!/usr/bin/env python\n"
                      "from sys import stderr\n"
                      "stderr.write('letsencrypt %s\\n')" % version)
+    chmod(letsencrypt_path, S_IRUSR | S_IXUSR)
 
 
 class AutoTests(TestCase):
@@ -237,6 +239,11 @@ class AutoTests(TestCase):
     test suites.
 
     """
+    NEW_LE_AUTO = build_le_auto(
+            version='99.9.9',
+            requirements='letsencrypt==99.9.9 --hash=sha256:1cc14d61ab424cdee446f51e50f1123f8482ec740587fe78626c933bba2873a0')
+    NEW_LE_AUTO_SIG = signed(NEW_LE_AUTO)
+
     def test_successes(self):
         """Exercise most branches of letsencrypt-auto.
 
@@ -252,20 +259,16 @@ class AutoTests(TestCase):
            the next, saving code.
 
         """
-        NEW_LE_AUTO = build_le_auto(
-                version='99.9.9',
-                requirements='letsencrypt==99.9.9 --hash=sha256:1cc14d61ab424cdee446f51e50f1123f8482ec740587fe78626c933bba2873a0')
-        NEW_LE_AUTO_SIG = signed(NEW_LE_AUTO)
-
-        with ephemeral_dir() as venv_dir:
+        with temp_paths() as (le_auto_path, venv_dir):
             # This serves a PyPI page with a higher version, a GitHub-alike
             # with a corresponding le-auto script, and a matching signature.
             resources = {'certbot/json': dumps({'releases': {'99.9.9': None}}),
-                         'v99.9.9/letsencrypt-auto': NEW_LE_AUTO,
-                         'v99.9.9/letsencrypt-auto.sig': NEW_LE_AUTO_SIG}
+                         'v99.9.9/letsencrypt-auto': self.NEW_LE_AUTO,
+                         'v99.9.9/letsencrypt-auto.sig': self.NEW_LE_AUTO_SIG}
             with serving(resources) as base_url:
                 run_letsencrypt_auto = partial(
                         run_le_auto,
+                        le_auto_path,
                         venv_dir,
                         base_url,
                         PIP_FIND_LINKS=join(tests_dir(),
@@ -274,7 +277,7 @@ class AutoTests(TestCase):
 
                 # Test when a phase-1 upgrade is needed, there's no LE binary
                 # installed, and pip hashes verify:
-                install_le_auto(build_le_auto(version='50.0.0'), venv_dir)
+                install_le_auto(build_le_auto(version='50.0.0'), le_auto_path)
                 out, err = run_letsencrypt_auto()
                 ok_(re.match(r'letsencrypt \d+\.\d+\.\d+',
                              err.strip().splitlines()[-1]))
@@ -291,16 +294,28 @@ class AutoTests(TestCase):
                 self.assertFalse('Upgrading certbot-auto ' in out)
                 self.assertFalse('Creating virtual environment...' in out)
 
-                # Test when a phase-1 upgrade is not needed but a phase-2
-                # upgrade is:
+    def test_phase2_upgrade(self):
+        """Test a phase-2 upgrade without a phase-1 upgrade."""
+        with temp_paths() as (le_auto_path, venv_dir):
+            resources = {'certbot/json': dumps({'releases': {'99.9.9': None}}),
+                         'v99.9.9/letsencrypt-auto': self.NEW_LE_AUTO,
+                         'v99.9.9/letsencrypt-auto.sig': self.NEW_LE_AUTO_SIG}
+            with serving(resources) as base_url:
+                venv_bin = join(venv_dir, 'bin')
+                makedirs(venv_bin)
                 set_le_script_version(venv_dir, '0.0.1')
-                out, err = run_letsencrypt_auto()
+
+                install_le_auto(self.NEW_LE_AUTO, le_auto_path)
+                pip_find_links=join(tests_dir(), 'fake-letsencrypt', 'dist')
+                out, err = run_le_auto(le_auto_path, venv_dir, base_url,
+                                       PIP_FIND_LINKS=pip_find_links)
+
                 self.assertFalse('Upgrading certbot-auto ' in out)
                 self.assertTrue('Creating virtual environment...' in out)
 
     def test_openssl_failure(self):
         """Make sure we stop if the openssl signature check fails."""
-        with ephemeral_dir() as venv_dir:
+        with temp_paths() as (le_auto_path, venv_dir):
             # Serve an unrelated hash signed with the good key (easier than
             # making a bad key, and a mismatch is a mismatch):
             resources = {'': '<a href="certbot/">certbot/</a>',
@@ -308,9 +323,9 @@ class AutoTests(TestCase):
                          'v99.9.9/letsencrypt-auto': build_le_auto(version='99.9.9'),
                          'v99.9.9/letsencrypt-auto.sig': signed('something else')}
             with serving(resources) as base_url:
-                copy(LE_AUTO_PATH, venv_dir)
+                copy(LE_AUTO_PATH, le_auto_path)
                 try:
-                    out, err = run_le_auto(venv_dir, base_url)
+                    out, err = run_le_auto(le_auto_path, venv_dir, base_url)
                 except CalledProcessError as exc:
                     eq_(exc.returncode, 1)
                     self.assertTrue("Couldn't verify signature of downloaded "
@@ -320,7 +335,7 @@ class AutoTests(TestCase):
 
     def test_pip_failure(self):
         """Make sure pip stops us if there is a hash mismatch."""
-        with ephemeral_dir() as venv_dir:
+        with temp_paths() as (le_auto_path, venv_dir):
             resources = {'': '<a href="certbot/">certbot/</a>',
                          'certbot/json': dumps({'releases': {'99.9.9': None}})}
             with serving(resources) as base_url:
@@ -329,14 +344,14 @@ class AutoTests(TestCase):
                     build_le_auto(
                         version='99.9.9',
                         requirements='configobj==5.0.6 --hash=sha256:badbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadb'),
-                    venv_dir)
+                    le_auto_path)
                 try:
-                    out, err = run_le_auto(venv_dir, base_url)
+                    out, err = run_le_auto(le_auto_path, venv_dir, base_url)
                 except CalledProcessError as exc:
                     eq_(exc.returncode, 1)
                     self.assertTrue("THESE PACKAGES DO NOT MATCH THE HASHES "
                                     "FROM THE REQUIREMENTS FILE" in exc.output)
-                    ok_(not exists(join(venv_dir, 'letsencrypt')),
+                    ok_(not exists(venv_dir),
                         msg="The virtualenv was left around, even though "
                             "installation didn't succeed. We shouldn't do "
                             "this, as it foils our detection of whether we "