Shellcheck compliance and double bracket conditions

dns_scripts/dns_add_hetzner

@@ -20,15 +20,15 @@ if [[ -z "$HETZNER_KEY" ]]; then
   echo "HETZNER_KEY variable not set"
   exit 1
 fi
-if [ -z "$HETZNER_ZONE_ID" ] && [ -z "$HETZNER_ZONE_NAME" ] ; then
+if [[ -z "$HETZNER_ZONE_ID" && -z "$HETZNER_ZONE_NAME" ]] ; then
   echo "HETZNER_ZONE_ID and HETZNER_ZONE_NAME variables not set"
   exit 1
 fi
 
 # Get Zone ID if not set
-if [ -z "$HETZNER_ZONE_ID" ] ; then
-  zone_id=$(curl --silent -X GET "$api_url/zones?name=$HETZNER_ZONE_NAME" -H 'Auth-API-Token: '"$api_key"'' | jq -r '.zones[0].id')
-  if [ -z "$zone_id" == "null" ] ; then
+if [[ -z "$HETZNER_ZONE_ID" ]] ; then
+  zone_id=$(curl --silent -X GET "$api_url/zones?name=$zone_name" -H 'Auth-API-Token: '"$api_key"'' | jq -r '.zones[0].id')
+  if [[ "$zone_id" == "null" ]] ; then
     echo "Zone ID not found"
     exit 1
   fi
@@ -40,10 +40,10 @@ txtname="_acme-challenge.$fulldomain."
 response=$(curl --silent -X POST "$api_url/records" \
      -H 'Content-Type: application/json' \
      -H "Auth-API-Token: $api_key" \
-     -d '{"value": "'$token'","ttl": 60,"type": "TXT","name": "_acme-challenge.'$fulldomain'.","zone_id": "'$zone_id'"}' \
+     -d '{"value": "'"$token"'","ttl": 60,"type": "TXT","name": "'"$txtname"'","zone_id": "'"$zone_id"'"}' \
      -o /dev/null -w '%{http_code}')
 
-if [  "$response" != "200" ] ; then
+if [[ "$response" != "200" ]] ; then
   echo "Record not created"
   echo "Response code: $response"
   exit 1

dns_scripts/dns_del_hetzner

@@ -20,15 +20,15 @@ if [[ -z "$HETZNER_KEY" ]]; then
   echo "HETZNER_KEY variable not set"
   exit 1
 fi
-if [ -z "$HETZNER_ZONE_ID" ] && [ -z "$HETZNER_ZONE_NAME" ] ; then
+if [[ -z "$HETZNER_ZONE_ID" && -z "$HETZNER_ZONE_NAME" ]] ; then
   echo "HETZNER_ZONE_ID and HETZNER_ZONE_NAME variables not set"
   exit 1
 fi
 
 # Get Zone ID if not set
-if [ -z "$HETZNER_ZONE_ID" ] ; then
-  zone_id=$(curl --silent -X GET "$api_url/zones?name=$HETZNER_ZONE_NAME" -H 'Auth-API-Token: '"$api_key"'' | jq -r '.zones[0].id')
-  if [  "$zone_id" == "null" ] ; then
+if [[ -z "$HETZNER_ZONE_ID" ]] ; then
+  zone_id=$(curl --silent -X GET "$api_url/zones?name=$zone_name" -H 'Auth-API-Token: '"$api_key"'' | jq -r '.zones[0].id')
+  if [[  "$zone_id" == "null" ]] ; then
     echo "Zone by name not found"
     exit 1
   fi
@@ -39,9 +39,9 @@ fi
 txtname="_acme-challenge.$fulldomain."
 
 
-record_id=$(curl --silent -X GET "$api_url/records?zone_id=$zone_id" -H "Auth-API-Token: $api_key" | jq -r '.records[] | select(.name=="'$txtname'") | .id')
+record_id=$(curl --silent -X GET "$api_url/records?zone_id=$zone_id" -H "Auth-API-Token: $api_key" | jq -r '.records[] | select(.name=="'"$txtname"'") | .id')
 
-if [  "$record_id" == "null" ] ; then
+if [[ "$record_id" == "null" ]] ; then
   echo "Record not found"
   exit 1
 fi
@@ -49,7 +49,7 @@ fi
 # Create TXT record
 response=$(curl --silent -X DELETE "$api_url/records/$record_id" -H "Auth-API-Token: $api_key" -o /dev/null -w '%{http_code}')
 
-if [  "$response" != "200" ] ; then
+if [[ "$response" != "200" ]] ; then
   echo "Record not deleted"
   echo "Response code: $response"
   exit 1