src: change generic exception types to be more explicit

Replace exception types to be more explicit about the nature of
the error.
Improve the exception raising semantics by using the 'from' keyword,
this wraps an older exception into a new one so it is still considered
the same object.

2 files changed, 9 insertions, 9 deletions

diff --git a/src/virtual/ogOperations.py b/src/virtual/ogOperations.py
index 930382d..0819a76 100644
--- a/src/virtual/ogOperations.py
+++ b/src/virtual/ogOperations.py
@@ -97,7 +97,7 @@ class OgQMP:
             self.sock.connect((self.ip, self.port))
         except socket.error as err:
             if err.errno == errno.ECONNREFUSED:
-                raise Exception('cannot connect to qemu')
+                raise RuntimeError('Cannot connect to QEMU')
             elif err.errno == errno.EINPROGRESS:
                 pass
 
@@ -114,11 +114,11 @@ class OgQMP:
                 pass
 
         if 'QMP' not in out:
-            raise Exception('cannot handshake qemu')
+            raise RuntimeError('Cannot handshake QEMU')
 
         out = self.talk(str({"execute": "qmp_capabilities"}))
         if 'return' not in out:
-            raise Exception('cannot handshake qemu')
+            raise RuntimeError('Cannot handshake QEMU')
 
     def disconnect(self):
         try:
@@ -142,10 +142,10 @@ class OgQMP:
         if self.sock in writable:
             try:
                 self.sock.send(bytes(data, 'utf-8'))
-            except:
-                raise Exception('cannot talk to qemu')
+            except Exception as e:
+                raise RuntimeError('Cannot talk to QEMU') from e
         else:
-            raise Exception('timeout when talking to qemu')
+            raise RuntimeError('Timeout when talking to QEMU')
 
         return self.recv(timeout=timeout)
 
@@ -158,9 +158,9 @@ class OgQMP:
                 out = self.sock.recv(4096).decode('utf-8')
                 out = json.loads(out)
             except socket.error as err:
-                raise Exception('cannot talk to qemu')
+                raise RuntimeError('Cannot talk to QEMU') from err
         else:
-            raise Exception('timeout when talking to qemu')
+            raise RuntimeError('Timeout when talking to QEMU')
         return out
 
 class OgVirtualOperations:
diff --git a/src/virtual/qmp.py b/src/virtual/qmp.py
index 5c8cf6a..96823d3 100644
--- a/src/virtual/qmp.py
+++ b/src/virtual/qmp.py
@@ -170,7 +170,7 @@ class QEMUMonitorProtocol(object):
         except socket.error as err:
             if err[0] == errno.EPIPE:
                 return
-            raise socket.error(err)
+            raise socket.error(err) from err
         resp = self.__json_read()
         self.logger.debug("<<< %s", resp)
         return resp