Improve VPS health response DTO and metrics

src/main/java/com/litoralregas/vpnprovisioner/vps/WireGuardVpsService.java

@@ -1,5 +1,8 @@
 package com.litoralregas.vpnprovisioner.vps;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.litoralregas.vpnprovisioner.vps.dto.VpsHealthResponse;
 import org.springframework.stereotype.Service;
 
 import java.util.HashSet;
@@ -14,9 +17,11 @@ public class WireGuardVpsService {
             Pattern.compile("\\b198\\.19\\.\\d{1,3}\\.\\d{1,3}\\b");
 
     private final SshService sshService;
+    private final ObjectMapper objectMapper;
 
-    public WireGuardVpsService(SshService sshService) {
+    public WireGuardVpsService(SshService sshService, ObjectMapper objectMapper) {
         this.sshService = sshService;
+        this.objectMapper = objectMapper;
     }
 
     public Set<String> findUsedVpnIps() {
@@ -66,7 +71,7 @@ public class WireGuardVpsService {
         );
     }
 
-    public String getVpsHealthJson() {
+    public VpsHealthResponse getVpsHealth() {
         SshCommandResult result = sshService.executeOnConfiguredVps(
                 "sudo /usr/local/sbin/lr-vps-health"
         );
@@ -77,7 +82,14 @@ public class WireGuardVpsService {
             );
         }
 
-        return result.stdout();
+        try {
+            return objectMapper.readValue(result.stdout(), VpsHealthResponse.class);
+        } catch (JsonProcessingException e) {
+            throw new IllegalStateException(
+                    "Invalid VPS health JSON returned by script",
+                    e
+            );
+        }
     }
 
     public String restoreLastWireGuardBackup() {