[#1319] Check if user exists before creating it

Author: fivitti

etc/hooks/deb/isc-stork-agent.postinst

@@ -13,9 +13,11 @@ setup_user () {
     chmod 700 "${home_dir}/tokens"
 
     # Add stork-agent user.
-    adduser --quiet --system --group --home $home_dir \
-            --no-create-home --disabled-password --disabled-login \
-            --gecos "Stork Agent User" stork-agent >/dev/null
+    if ! getent passwd stork-agent > /dev/null; then
+        adduser --quiet --system --group --home $home_dir \
+                --no-create-home --disabled-password --disabled-login \
+                --gecos "Stork Agent User" stork-agent >/dev/null
+    fi
 
     # Add stork-agent user to bind so it can read its config files.
     if getent group bind > /dev/null; then

etc/hooks/deb/isc-stork-server.postinst

@@ -4,9 +4,11 @@ set -eu
 
 setup_user () {
     # Sets up the stork-server user and its home directory.
-    adduser --quiet --system --group --home /var/lib/stork-server \
-        --no-create-home --disabled-password --disabled-login \
-        --gecos "Stork Server User" stork-server >/dev/null
+    if ! getent passwd stork-server > /dev/null; then
+        adduser --quiet --system --group --home /var/lib/stork-server \
+            --no-create-home --disabled-password --disabled-login \
+            --gecos "Stork Server User" stork-server >/dev/null
+    fi
 }
 
 after_install () {