Enhance error handling and HTTP codes in DCM

This improves error handling between DCM and the database resources and
adds/corrects a lot more HTTP return codes in the API, respectively.

Issue-ID: MULTICLOUD-1143
Change-Id: I3abc8025660e042f4c946f8bbfd280e1eb4c9583
Signed-off-by: Igor D.C <igor.duarte.cardoso@intel.com>

10 files changed, 74 insertions, 19 deletions

diff --git a/src/dcm/api/clusterHandler.go b/src/dcm/api/clusterHandler.go
index f4a3abdc..d0c1e62c 100644
--- a/src/dcm/api/clusterHandler.go
+++ b/src/dcm/api/clusterHandler.go
@@ -91,6 +91,10 @@ func (h clusterHandler) getHandler(w http.ResponseWriter, r *http.Request) {
 	} else {
 		ret, err = h.client.GetCluster(project, logicalCloud, name)
 		if err != nil {
+			if err.Error() == "Cluster Reference does not exist" {
+				http.Error(w, err.Error(), http.StatusNotFound)
+				return
+			}
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
@@ -131,12 +135,16 @@ func (h clusterHandler) updateHandler(w http.ResponseWriter, r *http.Request) {
 
 	ret, err := h.client.UpdateCluster(project, logicalCloud, name, v)
 	if err != nil {
+		if err.Error() == "Cluster Reference does not exist" {
+			http.Error(w, err.Error(), http.StatusNotFound)
+			return
+		}
 		http.Error(w, err.Error(),
 			http.StatusInternalServerError)
 		return
 	}
 	w.Header().Set("Content-Type", "application/json")
-	w.WriteHeader(http.StatusCreated)
+	w.WriteHeader(http.StatusOK)
 	err = json.NewEncoder(w).Encode(ret)
 	if err != nil {
 		http.Error(w, err.Error(),
diff --git a/src/dcm/api/keyValueHandler.go b/src/dcm/api/keyValueHandler.go
index c67504f2..a4a4f14a 100644
--- a/src/dcm/api/keyValueHandler.go
+++ b/src/dcm/api/keyValueHandler.go
@@ -90,6 +90,10 @@ func (h keyValueHandler) getHandler(w http.ResponseWriter, r *http.Request) {
 	} else {
 		ret, err = h.client.GetKVPair(project, logicalCloud, name)
 		if err != nil {
+			if err.Error() == "KV Pair does not exist" {
+				http.Error(w, err.Error(), http.StatusNotFound)
+				return
+			}
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
@@ -130,12 +134,16 @@ func (h keyValueHandler) updateHandler(w http.ResponseWriter, r *http.Request) {
 
 	ret, err := h.client.UpdateKVPair(project, logicalCloud, name, v)
 	if err != nil {
+		if err.Error() == "KV Pair does not exist" {
+			http.Error(w, err.Error(), http.StatusNotFound)
+			return
+		}
 		http.Error(w, err.Error(),
 			http.StatusInternalServerError)
 		return
 	}
 	w.Header().Set("Content-Type", "application/json")
-	w.WriteHeader(http.StatusCreated)
+	w.WriteHeader(http.StatusOK)
 	err = json.NewEncoder(w).Encode(ret)
 	if err != nil {
 		http.Error(w, err.Error(),
diff --git a/src/dcm/api/logicalCloudHandler.go b/src/dcm/api/logicalCloudHandler.go
index d9a3e5f5..36ec4e05 100644
--- a/src/dcm/api/logicalCloudHandler.go
+++ b/src/dcm/api/logicalCloudHandler.go
@@ -91,6 +91,10 @@ func (h logicalCloudHandler) getHandler(w http.ResponseWriter, r *http.Request)
 	} else {
 		ret, err = h.client.Get(project, name)
 		if err != nil {
+			if err.Error() == "Logical Cloud does not exist" {
+				http.Error(w, err.Error(), http.StatusNotFound)
+				return
+			}
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
@@ -129,6 +133,10 @@ func (h logicalCloudHandler) updateHandler(w http.ResponseWriter, r *http.Reques
 
 	ret, err := h.client.Update(project, name, v)
 	if err != nil {
+		if err.Error() == "Logical Cloud does not exist" {
+			http.Error(w, err.Error(), http.StatusNotFound)
+			return
+		}
 		http.Error(w, err.Error(),
 			http.StatusInternalServerError)
 		return
@@ -150,6 +158,10 @@ func (h logicalCloudHandler) deleteHandler(w http.ResponseWriter, r *http.Reques
 
 	err := h.client.Delete(project, name)
 	if err != nil {
+		if err.Error() == "Logical Cloud does not exist" {
+			http.Error(w, err.Error(), http.StatusNotFound)
+			return
+		}
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
@@ -165,6 +177,10 @@ func (h logicalCloudHandler) applyHandler(w http.ResponseWriter, r *http.Request
 	// Get logical cloud
 	lc, err := h.client.Get(project, name)
 	if err != nil {
+		if err.Error() == "Logical Cloud does not exist" {
+			http.Error(w, err.Error(), http.StatusNotFound)
+			return
+		}
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
@@ -173,6 +189,10 @@ func (h logicalCloudHandler) applyHandler(w http.ResponseWriter, r *http.Request
 	clusters, err := h.clusterClient.GetAllClusters(project, name)
 
 	if err != nil {
+		if err.Error() == "No Cluster References associated" {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
diff --git a/src/dcm/api/quotaHandler.go b/src/dcm/api/quotaHandler.go
index deb18e18..fd9b40f8 100644
--- a/src/dcm/api/quotaHandler.go
+++ b/src/dcm/api/quotaHandler.go
@@ -91,6 +91,10 @@ func (h quotaHandler) getHandler(w http.ResponseWriter, r *http.Request) {
 	} else {
 		ret, err = h.client.GetQuota(project, logicalCloud, name)
 		if err != nil {
+			if err.Error() == "Cluster Quota does not exist" {
+				http.Error(w, err.Error(), http.StatusNotFound)
+				return
+			}
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
@@ -131,12 +135,16 @@ func (h quotaHandler) updateHandler(w http.ResponseWriter, r *http.Request) {
 
 	ret, err := h.client.UpdateQuota(project, logicalCloud, name, v)
 	if err != nil {
+		if err.Error() == "Cluster Quota does not exist" {
+			http.Error(w, err.Error(), http.StatusNotFound)
+			return
+		}
 		http.Error(w, err.Error(),
 			http.StatusInternalServerError)
 		return
 	}
 	w.Header().Set("Content-Type", "application/json")
-	w.WriteHeader(http.StatusCreated)
+	w.WriteHeader(http.StatusOK)
 	err = json.NewEncoder(w).Encode(ret)
 	if err != nil {
 		http.Error(w, err.Error(),
diff --git a/src/dcm/api/userPermissionsHandler.go b/src/dcm/api/userPermissionsHandler.go
index 156c390f..3ac955fa 100644
--- a/src/dcm/api/userPermissionsHandler.go
+++ b/src/dcm/api/userPermissionsHandler.go
@@ -89,8 +89,12 @@ func (h userPermissionHandler) getHandler(w http.ResponseWriter, r *http.Request
 			return
 		}
 	} else {
-		ret, err = h.client.GetAllUserPerms(project, logicalCloud)
+		ret, err = h.client.GetUserPerm(project, logicalCloud, name)
 		if err != nil {
+			if err.Error() == "User Permission does not exist" {
+				http.Error(w, err.Error(), http.StatusNotFound)
+				return
+			}
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
@@ -131,12 +135,16 @@ func (h userPermissionHandler) updateHandler(w http.ResponseWriter, r *http.Requ
 
 	ret, err := h.client.UpdateUserPerm(project, logicalCloud, name, v)
 	if err != nil {
+		if err.Error() == "User Permission does not exist" {
+			http.Error(w, err.Error(), http.StatusNotFound)
+			return
+		}
 		http.Error(w, err.Error(),
 			http.StatusInternalServerError)
 		return
 	}
 	w.Header().Set("Content-Type", "application/json")
-	w.WriteHeader(http.StatusCreated)
+	w.WriteHeader(http.StatusOK)
 	err = json.NewEncoder(w).Encode(ret)
 	if err != nil {
 		http.Error(w, err.Error(),
diff --git a/src/dcm/pkg/module/cluster.go b/src/dcm/pkg/module/cluster.go
index 206d79a6..85b20117 100644
--- a/src/dcm/pkg/module/cluster.go
+++ b/src/dcm/pkg/module/cluster.go
@@ -133,7 +133,7 @@ func (v *ClusterClient) GetCluster(project, logicalCloud, clusterReference strin
 		return cl, nil
 	}
 
-	return Cluster{}, pkgerrors.New("Error getting Cluster")
+	return Cluster{}, pkgerrors.New("Cluster Reference does not exist")
 }
 
 // GetAll returns all cluster references in the logical cloud
@@ -149,6 +149,9 @@ func (v *ClusterClient) GetAllClusters(project, logicalCloud string) ([]Cluster,
 	if err != nil {
 		return []Cluster{}, pkgerrors.Wrap(err, "Get All Cluster references")
 	}
+	if len(values) == 0 {
+		return []Cluster{}, pkgerrors.New("No Cluster References associated")
+	}
 
 	for _, value := range values {
 		cl := Cluster{}
@@ -188,12 +191,12 @@ func (v *ClusterClient) UpdateCluster(project, logicalCloud, clusterReference st
 
 	//Check for name mismatch in cluster reference
 	if c.MetaData.ClusterReference != clusterReference {
-		return Cluster{}, pkgerrors.New("Update Error - Cluster reference mismatch")
+		return Cluster{}, pkgerrors.New("Cluster Reference mismatch")
 	}
 	//Check if this Cluster reference exists
 	_, err := v.GetCluster(project, logicalCloud, clusterReference)
 	if err != nil {
-		return Cluster{}, pkgerrors.New("Update Error - Cluster reference doesn't exist")
+		return Cluster{}, pkgerrors.New("Cluster Reference does not exist")
 	}
 	err = v.util.DBInsert(v.storeName, key, nil, v.tagMeta, c)
 	if err != nil {
diff --git a/src/dcm/pkg/module/keyvalue.go b/src/dcm/pkg/module/keyvalue.go
index 37c74a84..0127a6f4 100644
--- a/src/dcm/pkg/module/keyvalue.go
+++ b/src/dcm/pkg/module/keyvalue.go
@@ -133,7 +133,7 @@ func (v *KeyValueClient) GetKVPair(project, logicalCloud, kvPairName string) (Ke
 		return kv, nil
 	}
 
-	return KeyValue{}, pkgerrors.New("Error getting Key Value")
+	return KeyValue{}, pkgerrors.New("Key Value does not exist")
 }
 
 // Get All lists all key value pairs
@@ -194,7 +194,7 @@ func (v *KeyValueClient) UpdateKVPair(project, logicalCloud, kvPairName string,
 	//Check if this Key Value exists
 	_, err := v.GetKVPair(project, logicalCloud, kvPairName)
 	if err != nil {
-		return KeyValue{}, pkgerrors.New("Update Error - Key Value Pair doesn't exist")
+		return KeyValue{}, pkgerrors.New("KV Pair does not exist")
 	}
 	err = v.util.DBInsert(v.storeName, key, nil, v.tagMeta, c)
 	if err != nil {
diff --git a/src/dcm/pkg/module/logicalcloud.go b/src/dcm/pkg/module/logicalcloud.go
index 51ee387d..7d3c806b 100644
--- a/src/dcm/pkg/module/logicalcloud.go
+++ b/src/dcm/pkg/module/logicalcloud.go
@@ -145,7 +145,7 @@ func (v *LogicalCloudClient) Get(project, logicalCloudName string) (LogicalCloud
 	}
 	value, err := v.util.DBFind(v.storeName, key, v.tagMeta)
 	if err != nil {
-		return LogicalCloud{}, pkgerrors.Wrap(err, "Get Logical Cloud")
+		return LogicalCloud{}, pkgerrors.Wrap(err, "Error getting Logical Cloud")
 	}
 
 	//value is a byte array
@@ -153,12 +153,12 @@ func (v *LogicalCloudClient) Get(project, logicalCloudName string) (LogicalCloud
 		lc := LogicalCloud{}
 		err = v.util.DBUnmarshal(value[0], &lc)
 		if err != nil {
-			return LogicalCloud{}, pkgerrors.Wrap(err, "Unmarshaling value")
+			return LogicalCloud{}, pkgerrors.Wrap(err, "Error unmarshaling value")
 		}
 		return lc, nil
 	}
 
-	return LogicalCloud{}, pkgerrors.New("Error getting Logical Cloud")
+	return LogicalCloud{}, pkgerrors.New("Logical Cloud does not exist")
 }
 
 // GetAll returns Logical Clouds in the project
@@ -213,12 +213,12 @@ func (v *LogicalCloudClient) Update(project, logicalCloudName string, c LogicalC
 	}
 	// Check for mismatch, logicalCloudName and payload logical cloud name
 	if c.MetaData.LogicalCloudName != logicalCloudName {
-		return LogicalCloud{}, pkgerrors.New("Update Error - Logical Cloud name mismatch")
+		return LogicalCloud{}, pkgerrors.New("Logical Cloud name mismatch")
 	}
 	//Check if this Logical Cloud exists
 	_, err := v.Get(project, logicalCloudName)
 	if err != nil {
-		return LogicalCloud{}, pkgerrors.New("Update Error - Logical Cloud doesn't exist")
+		return LogicalCloud{}, pkgerrors.New("Logical Cloud does not exist")
 	}
 	err = v.util.DBInsert(v.storeName, key, nil, v.tagMeta, c)
 	if err != nil {
diff --git a/src/dcm/pkg/module/quota.go b/src/dcm/pkg/module/quota.go
index cbd9c8b7..8e15a794 100644
--- a/src/dcm/pkg/module/quota.go
+++ b/src/dcm/pkg/module/quota.go
@@ -152,7 +152,7 @@ func (v *QuotaClient) GetQuota(project, logicalCloud, quotaName string) (Quota,
 		return q, nil
 	}
 
-	return Quota{}, pkgerrors.New("Error getting Quota")
+	return Quota{}, pkgerrors.New("Cluster Quota does not exist")
 }
 
 // GetAll returns all cluster quotas in the logical cloud
@@ -211,7 +211,7 @@ func (v *QuotaClient) UpdateQuota(project, logicalCloud, quotaName string, c Quo
 	//Check if this Quota exists
 	_, err := v.GetQuota(project, logicalCloud, quotaName)
 	if err != nil {
-		return Quota{}, pkgerrors.New("Update Error - Quota doesn't exist")
+		return Quota{}, pkgerrors.New("Cluster Quota does not exist")
 	}
 	err = v.util.DBInsert(v.storeName, key, nil, v.tagMeta, c)
 	if err != nil {
diff --git a/src/dcm/pkg/module/userpermissions.go b/src/dcm/pkg/module/userpermissions.go
index 2cff712b..4c918f0f 100644
--- a/src/dcm/pkg/module/userpermissions.go
+++ b/src/dcm/pkg/module/userpermissions.go
@@ -124,7 +124,7 @@ func (v *UserPermissionClient) GetUserPerm(project, logicalCloud, userPermName s
 		return up, nil
 	}
 
-	return UserPermission{}, pkgerrors.New("Error getting User Permission")
+	return UserPermission{}, pkgerrors.New("User Permission does not exist")
 }
 
 // GetAll lists all user permissions
@@ -184,7 +184,7 @@ func (v *UserPermissionClient) UpdateUserPerm(project, logicalCloud, userPermNam
 	_, err := v.GetUserPerm(project, logicalCloud, userPermName)
 	if err != nil {
 		return UserPermission{}, pkgerrors.New(
-			"Update Error - User Permission doesn't exist")
+			"User Permission does not exist")
 	}
 	err = v.util.DBInsert(v.storeName, key, nil, v.tagMeta, c)
 	if err != nil {