k8s: fix cassandra-tool env key conflict with k8s (cadence-workflow#3505

)

*  k8s: fix cassandra-tool env key conflict with k8s

1. The default CASSANDRA_PORT key is used by k8s when you have an
service pod named cassandra(k8s will gen a env key which is name_port).
And the CASSANDRA_PORT has valid value which is an url, cannot be 
parsed to an int value. Finally, the cadence-cassandra-tool can not be
executed. Candence cannot work well when need cadence-canssandra.
2. Replace the CASSANDRA_PORT to CASSANDRA_DB_PORT, to avoid
use the same key with k8s. 

* tools: terminated with a non-zero exit code

1. When cannot run
2. These tools depend on some environment vars, which are not really
reliable. In that case, tools start and stop without any stdout.

cmd/tools/cassandra/main.go

@@ -27,5 +27,8 @@ import (
 )
 
 func main() {
-	cassandra.RunTool(os.Args) //nolint:errcheck
+	err := cassandra.RunTool(os.Args)
+	if err != nil {
+		panic(err)
+	}
 }

cmd/tools/cli/main.go

@@ -30,5 +30,8 @@ import (
 // See cadence/tools/cli/README.md for usage
 func main() {
 	app := cli.NewCliApp()
-	app.Run(os.Args)
+	err := app.Run(os.Args)
+	if err != nil {
+		panic(err)
+	}
 }

cmd/tools/sql/main.go

@@ -29,5 +29,8 @@ import (
 )
 
 func main() {
-	sql.RunTool(os.Args) //nolint:errcheck
+	err := sql.RunTool(os.Args)
+	if err != nil {
+		panic(err)
+	}
 }

environment/env.go

@@ -33,7 +33,7 @@ const (
 	// CassandraSeeds env
 	CassandraSeeds = "CASSANDRA_SEEDS"
 	// CassandraPort env
-	CassandraPort = "CASSANDRA_PORT"
+	CassandraPort = "CASSANDRA_DB_PORT"
 	// CassandraDefaultPort Cassandra default port
 	CassandraDefaultPort = "9042"
 

tools/cassandra/main.go

@@ -73,7 +73,7 @@ func buildCLIOptions() *cli.App {
 			Name:   schema.CLIFlagPort,
 			Value:  defaultCassandraPort,
 			Usage:  "Port of cassandra host to connect to",
-			EnvVar: "CASSANDRA_PORT",
+			EnvVar: "CASSANDRA_DB_PORT",
 		},
 		cli.StringFlag{
 			Name:   schema.CLIFlagUser,