Fix a few ShellCheck reported warnings from PR #213

The checks on the upstream project have reported some warnings to the
code accepted in PR #213, fix them in this commit.

Signed-off-by: Marco Chiappero <marco.chiappero@suse.com>

ironic-image/scripts/configure-ironic.sh

@@ -53,7 +53,7 @@ wait_for_interface_or_ip
 
 if [[ "$(echo "$LISTEN_ALL_INTERFACES" | tr '[:upper:]' '[:lower:]')" == "true" ]]; then
 export IRONIC_HOST_IP="::"
-elif [[ -n "$ENABLE_IPV6" ]]; then
+elif [[ -n "${ENABLE_IPV6}" ]]; then
 export IRONIC_HOST_IP="$IRONIC_IPV6"
 else
 export IRONIC_HOST_IP="$IRONIC_IP"

ironic-image/scripts/ironic-common.sh

@@ -55,7 +55,7 @@ get_ip_of_hostname()
 
     local HOSTNAME=$1
 
-    echo $(nslookup -type=${QUERY} "$HOSTNAME" | tail -n2 | grep -w "Address:" | cut -d " " -f2)
+    echo $(nslookup -type=${QUERY} "${HOSTNAME}" | tail -n2 | grep -w "Address:" | cut -d " " -f2)
 }
 
 get_interface_of_ip()
@@ -85,7 +85,7 @@ get_interface_of_ip()
     # For IPv6 addresses, this will give the short-form address
     IP_ADDR="$(ipcalc "${IP_ADDR}" | grep "^Address:" | awk '{print $2}')"
 
-    echo $(ip "$IP_VERS" -br addr show scope global | grep -i " ${IP_ADDR}/" | cut -f 1 -d ' ' | cut -f 1 -d '@')
+    echo $(ip "${IP_VERS}" -br addr show scope global | grep -i " ${IP_ADDR}/" | cut -f 1 -d ' ' | cut -f 1 -d '@')
 }
 
 get_ip_of_interface()
@@ -111,7 +111,7 @@ get_ip_of_interface()
 
     local IFACE=$1
 
-    echo $(ip "$IP_VERS" -br addr show scope global up dev $IFACE | awk '{print $3}' | sed -e 's%/.*%%' | head -n 1)
+    echo $(ip "${IP_VERS}" -br addr show scope global up dev ${IFACE} | awk '{print $3}' | sed -e 's%/.*%%' | head -n 1)
 }
 
 get_provisioning_interface()
@@ -150,7 +150,7 @@ wait_for_interface_or_ip()
 
         until [[ -n "$IFACE_OF_IP" ]]; do
             echo "Waiting for ${PROVISIONING_IP} to be configured on an interface..."
-            IFACE_OF_IP="$(get_interface_of_ip "$PROVISIONING_IP")"
+            IFACE_OF_IP="$(get_interface_of_ip "${PROVISIONING_IP}")"
             sleep 1
         done
 
@@ -167,10 +167,10 @@ wait_for_interface_or_ip()
         until [[ -n "$IRONIC_IPV6" ]] || [[ -n "$IRONIC_IP" ]]; do
             echo "Waiting for ${PROVISIONING_INTERFACE} interface to be configured..."
 
-            IRONIC_IPV6="$(get_ip_of_interface "$PROVISIONING_INTERFACE" 6)"
+            IRONIC_IPV6="$(get_ip_of_interface "${PROVISIONING_INTERFACE}" 6)"
             sleep 1
 
-            IRONIC_IP="$(get_ip_of_interface "$PROVISIONING_INTERFACE" 4)"
+            IRONIC_IP="$(get_ip_of_interface "${PROVISIONING_INTERFACE}" 4)"
             sleep 1
         done
 
@@ -191,21 +191,21 @@ wait_for_interface_or_ip()
             local IPV6_RECORD=""
             local IPV4_RECORD=""
 
-            IPV6_RECORD="$(get_ip_of_hostname "$IRONIC_URL_HOSTNAME" 6)"
-            IPV4_RECORD="$(get_ip_of_hostname "$IRONIC_URL_HOSTNAME" 4)"
+            IPV6_RECORD="$(get_ip_of_hostname "${IRONIC_URL_HOSTNAME}" 6)"
+            IPV4_RECORD="$(get_ip_of_hostname "${IRONIC_URL_HOSTNAME}" 4)"
 
             # We couldn't get any IP
             if [[ -z "$IPV4_RECORD" ]] && [[ -z "$IPV6_RECORD" ]]; then
-                echo "${FUNCNAME}: no valid IP found for hostname $IRONIC_URL_HOSTNAME" >&2
+                echo "${FUNCNAME}: no valid IP found for hostname ${IRONIC_URL_HOSTNAME}" >&2
                 return 1
             fi
 
             echo "Waiting for ${IPV6_RECORD} to be configured on an interface"
-            IPV6_IFACE="$(get_interface_of_ip "$IPV6_RECORD" 6)"
+            IPV6_IFACE="$(get_interface_of_ip "${IPV6_RECORD}" 6)"
             sleep 1
 
             echo "Waiting for ${IPV4_RECORD} to be configured on an interface"
-            IPV4_IFACE="$(get_interface_of_ip "$IPV4_RECORD" 4)"
+            IPV4_IFACE="$(get_interface_of_ip "${IPV4_RECORD}" 4)"
             sleep 1
         done
 
@@ -238,7 +238,7 @@ wait_for_interface_or_ip()
     fi
     if [[ -n "$IRONIC_IPV6" ]]; then
         export ENABLE_IPV6=yes
-        export IRONIC_URL_HOST="[$IRONIC_IPV6]" # The HTTP host needs surrounding with brackets
+        export IRONIC_URL_HOST="[${IRONIC_IPV6}]" # The HTTP host needs surrounding with brackets
     fi
 
     # Once determined if we have IPv4 and/or IPv6, override the hostname if provided