diff --git a/de/heat-templates/scripts/instance_boot.sh b/de/heat-templates/scripts/instance_boot.sh
index db1a290..becccfe 100644
--- a/de/heat-templates/scripts/instance_boot.sh
+++ b/de/heat-templates/scripts/instance_boot.sh
@@ -615,7 +615,9 @@
 fi
 
     public_address_match_ip_line=$(grep -nm1 "${PUBLIC_NODE_IP_ADDRESS}/${PUBLIC_NODE_IP_NETMASK}" ${cloud_netplan_cfg} | cut -d: -f1)
-    sed -i "$((${public_address_match_ip_line}-1)),$((${public_address_match_ip_line}))d" ${cloud_netplan_cfg}
+    if [ -n "${public_address_match_ip_line}" ] ; then
+        sed -i "$((${public_address_match_ip_line}-1)),$((${public_address_match_ip_line}))d" ${cloud_netplan_cfg}
+    fi
 
 cat << EOF >> ${cloud_netplan_cfg}
     bridges:
diff --git a/trymos/image_build/files/usr/share/trymos/launch.sh b/trymos/image_build/files/usr/share/trymos/launch.sh
index 28de67f..04170b7 100755
--- a/trymos/image_build/files/usr/share/trymos/launch.sh
+++ b/trymos/image_build/files/usr/share/trymos/launch.sh
@@ -121,7 +121,9 @@
     sed -i "s/${DEFAULT_INTERFACE}:/&\n            critical: true/" ${cloud_netplan_cfg}
 
     public_address_match_ip_line=$(grep -nm1 "${PUBLIC_NODE_IP_ADDRESS}/${PUBLIC_NODE_IP_NETMASK}" ${cloud_netplan_cfg} | cut -d: -f1)
-    sed -i "$((${public_address_match_ip_line}-1)),$((${public_address_match_ip_line}))d" ${cloud_netplan_cfg}
+    if [ -n "${public_address_match_ip_line}" ] ; then
+        sed -i "$((${public_address_match_ip_line}-1)),$((${public_address_match_ip_line}))d" ${cloud_netplan_cfg}
+    fi
 
 cat << EOF >> ${cloud_netplan_cfg}
     bridges:
@@ -315,7 +317,7 @@
     done
     wait_for_pods openstack
 
-    kubectl -n openstack create job --from=cronjob/nova-cell-setup  nova-cell-setup-pd01-$(cat /dev/urandom | tr -dc '[a-z]' | head -c3)
+    kubectl -n openstack create job --from=cronjob/nova-cell-setup  nova-cell-setup-pd01-$(cat /dev/urandom | tr -dc a-z | head -c3)
     info "Openstack was deployed successfully..."
 }