handle nil pointer exception (#514)

Author: GokceGK

internal/cmd/beta/network/describe/describe.go

@@ -146,8 +146,12 @@ func outputResult(p *print.Printer, outputFormat string, network *iaas.Network)
 		table.AddSeparator()
 		table.AddRow("STATE", *network.State)
 		table.AddSeparator()
-		table.AddRow("PUBLIC IP", *network.PublicIp)
-		table.AddSeparator()
+
+		if network.PublicIp != nil {
+			table.AddRow("PUBLIC IP", *network.PublicIp)
+			table.AddSeparator()
+		}
+
 		if len(ipv4nameservers) > 0 {
 			table.AddRow("IPv4 NAME SERVERS", strings.Join(ipv4nameservers, ", "))
 		}

internal/cmd/beta/network/list/list.go

@@ -154,7 +154,12 @@ func outputResult(p *print.Printer, outputFormat string, networks []iaas.Network
 		table.SetHeader("ID", "Name", "Status", "Public IP")
 
 		for _, network := range networks {
-			table.AddRow(*network.NetworkId, *network.Name, *network.State, *network.PublicIp)
+			publicIp := ""
+			if network.PublicIp != nil {
+				publicIp = *network.PublicIp
+			}
+
+			table.AddRow(*network.NetworkId, *network.Name, *network.State, publicIp)
 			table.AddSeparator()
 		}