working valheim checkpoint

create-linode.sh

@@ -26,7 +26,8 @@ VOLUME_MOUNT="/mnt/$VOLUME_NAME"
 
 # StackScript that mounts the volume on first boot (see stackscript.md).
 # Enter the numeric StackScript ID manually after creating it in the Linode UI.
-STACKSCRIPT_ID="2225110"
+#STACKSCRIPT_ID="2225110"
+STACKSCRIPT_ID="2225140"
 
 if [[ "$SCRIPT_ACTION" == "" || "$SCRIPT_ACTION" == "--help" || "$SCRIPT_ACTION" == "-?" ]]; then
   echo "Linode helper script: create-linode.sh <action> <label> [args]"
@@ -38,6 +39,7 @@ if [[ "$SCRIPT_ACTION" == "" || "$SCRIPT_ACTION" == "--help" || "$SCRIPT_ACTION"
   echo "         create-linode.sh x <label> get <remote source> <local dest>"
   echo "         create-linode.sh x <label> put <local source> <remote dest>"
   echo "Update record: create-linode.sh a <label> <subdomain>"
+  echo "         (updates the existing A record, creates one if missing)"
   echo "List:    create-linode.sh l"
   echo "         (lists all Linodes, no label needed)"
 fi
@@ -118,6 +120,17 @@ if [[ "$SCRIPT_ACTION" == "d" ]]; then
   INSTANCE_ID=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .id' | sed -e "s/\"//g")
   echo "Destroying ID:$INSTANCE_ID Hit Ctrl-C in the next 10 seconds to cancel."
   sleep 15
+
+  # Shut the Linode down cleanly before deleting it, so systemd stops the
+  # Docker container and the Valheim server gets the chance to save the world
+  # rather than being cut off mid-write.
+  echo "Shutting down ID:$INSTANCE_ID..."
+  curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
+    -X POST https://api.linode.com/v4/linode/instances/$INSTANCE_ID/shutdown | jq .
+
+  # Give the shutdown time to finish before the instance is deleted.
+  sleep 30
+
   curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
     -X DELETE https://api.linode.com/v4/linode/instances/$INSTANCE_ID
   echo "$(date -Iminutes) --- Id:$INSTANCE_ID --- IP:$INSTANCE_IP Destroyed $LINODE_LABEL." >>$LOGFILE
@@ -154,30 +167,54 @@ if [[ "$SCRIPT_ACTION" == "a" ]]; then
   INSTANCE_IP=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .ipv4[]' | sed -e "s/\"//g")
 
   NI_SUBDOMAIN=$3
+  DOMAIN_RECORDS=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
+    https://api.linode.com/v4/domains/$WHICH_DOMAIN/records)
+
   echo "Previous value:"
-  curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
-    https://api.linode.com/v4/domains/$WHICH_DOMAIN/records | jq .
+  echo "$DOMAIN_RECORDS" | jq .
 
   sleep 3
 
+  # Update the A record that already exists for this subdomain rather than
+  # adding another one; a record is only created when there is nothing to
+  # update. DNS names are case-insensitive, so compare them that way.
+  RECORD_IDS=$(echo "$DOMAIN_RECORDS" | jq -r --arg name "$NI_SUBDOMAIN" \
+    '.data[] | select(.type == "A" and ((.name // "") | ascii_downcase) == ($name | ascii_downcase)) | .id')
+  RECORD_ID=$(echo "$RECORD_IDS" | head -n 1)
+  DUPLICATE_IDS=$(echo "$RECORD_IDS" | tail -n +2)
+
   echo "Updating records with ip $INSTANCE_IP..."
 
   #ni7ne:
-  curl -s -H "Content-Type: application/json" \
-    -H "Authorization: Bearer $LINODE_API_KEY" \
-    -X POST -d '{
-	  "type": "A",
-          "name": "'$NI_SUBDOMAIN'",
-          "target": "'$INSTANCE_IP'",
-          "priority": 0,
-          "weight": 0,
-          "port": 0,
-          "service": null,
-          "protocol": null,
-          "ttl_sec": 14400,
-          "tag": null
-        }' \
-    https://api.linode.com/v4/domains/$WHICH_DOMAIN/records | jq .
+  if [[ -n "$RECORD_ID" ]]; then
+    curl -s -H "Content-Type: application/json" \
+      -H "Authorization: Bearer $LINODE_API_KEY" \
+      -X PUT -d '{
+            "type": "A",
+            "name": "'$NI_SUBDOMAIN'",
+            "target": "'$INSTANCE_IP'",
+            "ttl_sec": 14400
+          }' \
+      https://api.linode.com/v4/domains/$WHICH_DOMAIN/records/$RECORD_ID | jq .
+
+    # Duplicates left behind by earlier runs would keep resolving to an old
+    # IP, so remove everything except the record that was just updated.
+    for DUPLICATE_ID in $DUPLICATE_IDS; do
+      echo "Deleting duplicate A record $DUPLICATE_ID for $NI_SUBDOMAIN..."
+      curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
+        -X DELETE https://api.linode.com/v4/domains/$WHICH_DOMAIN/records/$DUPLICATE_ID
+    done
+  else
+    curl -s -H "Content-Type: application/json" \
+      -H "Authorization: Bearer $LINODE_API_KEY" \
+      -X POST -d '{
+            "type": "A",
+            "name": "'$NI_SUBDOMAIN'",
+            "target": "'$INSTANCE_IP'",
+            "ttl_sec": 14400
+          }' \
+      https://api.linode.com/v4/domains/$WHICH_DOMAIN/records | jq .
+  fi
 
   echo "Update complete."