Fix permissions error when upgrading certbot-auto. (#5086) (#5089)

Now we always check if we have root access if --cb-auto-has-root is not given
on the command line. This allows certbot-auto to properly acquire root when
upgrading from an older version. People upgrading from 0.18.0 to 0.18.1 may
check for root access twice, however, if root's user ID is 0, this check is
essentially a noop. If root's user ID is not 0, we'll request root access a 2nd
time during this upgrade.
(cherry picked from commit 82d0ff1df249cdd6748b95aab73ec4aa19b24cb6)

2 files changed, 22 insertions, 10 deletions

diff --git a/letsencrypt-auto-source/letsencrypt-auto b/letsencrypt-auto-source/letsencrypt-auto
index 223fbfd32..254f02c0a 100755
--- a/letsencrypt-auto-source/letsencrypt-auto
+++ b/letsencrypt-auto-source/letsencrypt-auto
@@ -187,8 +187,7 @@ SetRootAuthMechanism() {
 
 if [ "$1" = "--cb-auto-has-root" ]; then
   shift 1
-elif [ "$1" != "--le-auto-phase2" ]; then
-  # if $1 is --le-auto-phase2, we've executed this branch before
+else
   SetRootAuthMechanism
   if [ -n "$SUDO" ]; then
     echo "Requesting to rerun $0 with root privileges..."
@@ -197,6 +196,14 @@ elif [ "$1" != "--le-auto-phase2" ]; then
   fi
 fi
 
+# Runs this script again with the given arguments. --cb-auto-has-root is added
+# to the command line arguments to ensure we don't try to acquire root a
+# second time. After the script is rerun, we exit the current script.
+RerunWithArgs() {
+    "$0" --cb-auto-has-root "$@"
+    exit 0
+}
+
 BootstrapMessage() {
   # Arguments: Platform name
   say "Bootstrapping dependencies for $1... (you can skip this with --no-bootstrap)"
@@ -825,8 +832,7 @@ if [ "$1" = "--le-auto-phase2" ]; then
       # if non-interactive mode or stdin and stdout are connected to a terminal
       if [ \( "$NONINTERACTIVE" = 1 \) -o \( \( -t 0 \) -a \( -t 1 \) \) ]; then
         rm -rf "$VENV_PATH"
-        "$0" "$@"
-        exit 0
+        RerunWithArgs "$@"
       else
         error "Skipping upgrade because new OS dependencies may need to be installed."
         error
@@ -1491,5 +1497,5 @@ UNLIKELY_EOF
     fi  # A newer version is available.
   fi  # Self-upgrading is allowed.
 
-  "$0" --le-auto-phase2 "$@"
+  RerunWithArgs --le-auto-phase2 "$@"
 fi
diff --git a/letsencrypt-auto-source/letsencrypt-auto.template b/letsencrypt-auto-source/letsencrypt-auto.template
index eb2b82776..4eef10c80 100755
--- a/letsencrypt-auto-source/letsencrypt-auto.template
+++ b/letsencrypt-auto-source/letsencrypt-auto.template
@@ -187,8 +187,7 @@ SetRootAuthMechanism() {
 
 if [ "$1" = "--cb-auto-has-root" ]; then
   shift 1
-elif [ "$1" != "--le-auto-phase2" ]; then
-  # if $1 is --le-auto-phase2, we've executed this branch before
+else
   SetRootAuthMechanism
   if [ -n "$SUDO" ]; then
     echo "Requesting to rerun $0 with root privileges..."
@@ -197,6 +196,14 @@ elif [ "$1" != "--le-auto-phase2" ]; then
   fi
 fi
 
+# Runs this script again with the given arguments. --cb-auto-has-root is added
+# to the command line arguments to ensure we don't try to acquire root a
+# second time. After the script is rerun, we exit the current script.
+RerunWithArgs() {
+    "$0" --cb-auto-has-root "$@"
+    exit 0
+}
+
 BootstrapMessage() {
   # Arguments: Platform name
   say "Bootstrapping dependencies for $1... (you can skip this with --no-bootstrap)"
@@ -406,8 +413,7 @@ if [ "$1" = "--le-auto-phase2" ]; then
       # if non-interactive mode or stdin and stdout are connected to a terminal
       if [ \( "$NONINTERACTIVE" = 1 \) -o \( \( -t 0 \) -a \( -t 1 \) \) ]; then
         rm -rf "$VENV_PATH"
-        "$0" "$@"
-        exit 0
+        RerunWithArgs "$@"
       else
         error "Skipping upgrade because new OS dependencies may need to be installed."
         error
@@ -567,5 +573,5 @@ UNLIKELY_EOF
     fi  # A newer version is available.
   fi  # Self-upgrading is allowed.
 
-  "$0" --le-auto-phase2 "$@"
+  RerunWithArgs --le-auto-phase2 "$@"
 fi