utils: handle EOFException during VR Health Check (#3919)

VR health check throws EOFException due to malformed/Invalid JSON.

Fixes #3893

Co-authored-by: Pearl Dsilva <pearl.dsilva@shapeblue.com>

Author: Pearl1594

server/src/main/java/com/cloud/network/router/VirtualNetworkApplianceManagerImpl.java

@@ -1531,7 +1531,6 @@ private List<RouterHealthCheckResult> updateDbHealthChecksFromRouterResponse(fin
         } catch (JsonSyntaxException ex) {
             s_logger.error("Unable to parse the result of health checks due to " + ex.getLocalizedMessage(), ex);
         }
-
         return Collections.emptyList();
     }
 

utils/src/main/java/com/cloud/utils/ssh/SshHelper.java

@@ -189,7 +189,6 @@ public static Pair<Boolean, String> sshExecute(String host, int port, String use
 
             byte[] buffer = new byte[8192];
             StringBuffer sbResult = new StringBuffer();
-
             int currentReadBytes = 0;
             while (true) {
                 throwSshExceptionIfStdoutOrStdeerIsNull(stdout, stderr);
@@ -207,22 +206,18 @@ public static Pair<Boolean, String> sshExecute(String host, int port, String use
                     if (canEndTheSshConnection(waitResultTimeoutInMs, sess, conditions)) {
                         break;
                     }
-
                 }
 
-                while (stdout.available() > 0) {
-                    currentReadBytes = stdout.read(buffer);
-                    sbResult.append(new String(buffer, 0, currentReadBytes));
+               while((currentReadBytes = stdout.read(buffer)) != -1) {
+                    sbResult.append(new String(buffer, 0 , currentReadBytes));
                 }
 
-                while (stderr.available() > 0) {
-                    currentReadBytes = stderr.read(buffer);
+                while((currentReadBytes = stderr.read(buffer)) != -1) {
                     sbResult.append(new String(buffer, 0, currentReadBytes));
                 }
             }
 
             String result = sbResult.toString();
-
             if (StringUtils.isBlank(result)) {
                 try {
                     result = IOUtils.toString(stdout, StandardCharsets.UTF_8);
@@ -243,7 +238,6 @@ public static Pair<Boolean, String> sshExecute(String host, int port, String use
                 s_logger.error(String.format("SSH execution of command %s has an error status code in return. Result output: %s", command, result));
                 return new Pair<Boolean, String>(false, result);
             }
-
             return new Pair<Boolean, String>(true, result);
         } finally {
             if (sess != null)