unify error handling accross all commands

- change in dpservice-go library: unified the return values of gRPC functions
- this fixes #639; empty struct is now always returned and accessing Status.Code field doesn't crash dpservice-cli
- changes in dpservice-cli: removed checking for Status.Code as it is handled by error value
- removed the check of Status.Code from RenderList(), Status is checked before, errorous Lists are not rendered and error is returned

Author: vlorinc

cli/dpservice-cli/cmd/capture_start.go

@@ -148,7 +148,7 @@ func RunCaptureStart(ctx context.Context, dpdkClientFactory DPDKClientFactory, r
 		},
 	})
 
-	if err != nil && capture.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error initializing packet capturing: %w", err)
 	}
 

cli/dpservice-cli/cmd/capture_status.go

@@ -46,7 +46,7 @@ func RunCaptureStatus(
 	}()
 
 	capture, err := client.CaptureStatus(ctx)
-	if err != nil && capture.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error checking initialization status: %w", err)
 	}
 

cli/dpservice-cli/cmd/capture_stop.go

@@ -41,7 +41,7 @@ func RunCaptureStop(ctx context.Context, dpdkClientFactory DPDKClientFactory, re
 
 	captureStop, err := dpdkClient.CaptureStop(ctx)
 
-	if err != nil && captureStop.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error stopping capturing: %w", err)
 	}
 

cli/dpservice-cli/cmd/common.go

@@ -158,22 +158,13 @@ func (o *RendererOptions) RenderObject(operation string, w io.Writer, obj api.Ob
 }
 
 func (o *RendererOptions) RenderList(operation string, w io.Writer, list api.List) error {
-	if list.GetStatus().Code != 0 {
-		operation = fmt.Sprintf("server error: %d, %s", list.GetStatus().Code, list.GetStatus().Message)
-		if o.Output == "table" {
-			o.Output = "name"
-		}
-	}
 	renderer, err := o.NewRenderer(operation, w)
 	if err != nil {
 		return fmt.Errorf("error creating renderer: %w", err)
 	}
 	if err := renderer.Render(list); err != nil {
 		return fmt.Errorf("error rendering %s: %w", list.GetItems()[0].GetKind(), err)
 	}
-	if list.GetStatus().Code != 0 {
-		return fmt.Errorf(strconv.Itoa(apierrors.SERVER_ERROR))
-	}
 	return nil
 }
 

cli/dpservice-cli/cmd/create_firewall_rule.go

@@ -199,7 +199,7 @@ func RunCreateFirewallRule(ctx context.Context, dpdkClientFactory DPDKClientFact
 				Filter: protocolFilter.Filter},
 		},
 	})
-	if err != nil && fwrule.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error creating firewall rule: %w", err)
 	}
 

cli/dpservice-cli/cmd/create_interface.go

@@ -97,7 +97,7 @@ func RunCreateInterface(ctx context.Context, dpdkClientFactory DPDKClientFactory
 			Metering: &api.MeteringParams{TotalRate: opts.TotalMeterRate, PublicRate: opts.PublicMeterRate},
 		},
 	})
-	if err != nil && iface.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error creating interface: %w", err)
 	}
 

cli/dpservice-cli/cmd/create_loadbalancer.go

@@ -93,7 +93,7 @@ func RunCreateLoadBalancer(ctx context.Context, dpdkClientFactory DPDKClientFact
 			Lbports: ports,
 		},
 	})
-	if err != nil && lb.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error creating loadbalancer: %w", err)
 	}
 

cli/dpservice-cli/cmd/create_loadbalancer_prefix.go

@@ -87,7 +87,7 @@ func RunCreateLoadBalancerPrefix(
 			Prefix: opts.Prefix,
 		},
 	})
-	if err != nil && lbprefix.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error creating loadbalancer prefix: %w", err)
 	}
 

cli/dpservice-cli/cmd/create_loadbalancer_target.go

@@ -84,7 +84,7 @@ func RunCreateLoadBalancerTarget(
 		LoadBalancerTargetMeta: api.LoadBalancerTargetMeta{LoadbalancerID: opts.LoadBalancerID},
 		Spec:                   api.LoadBalancerTargetSpec{TargetIP: &opts.TargetIP},
 	})
-	if err != nil && lbtarget.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error creating loadbalancer target: %w", err)
 	}
 

cli/dpservice-cli/cmd/create_nat.go

@@ -85,7 +85,7 @@ func RunCreateNat(ctx context.Context, dpdkClientFactory DPDKClientFactory, rend
 			MaxPort: opts.MaxPort,
 		},
 	})
-	if err != nil && nat.Status.Code == 0 {
+	if err != nil {
 		return fmt.Errorf("error creating nat: %w", err)
 	}