core: add optional parameters to cassandra (#57)

cassandra.go

@@ -10,7 +10,7 @@ import (
 // SetupCassandraContainer sets up a real Cassandra node for testing purposes,
 // using a Docker container. It returns the container ID and its IP address,
 // or makes the test fail on error.
-func SetupCassandraContainer(versionTag string) (c ContainerID, ip string, port int, err error) {
+func SetupCassandraContainer(versionTag string, optionalParams ...string) (c ContainerID, ip string, port int, err error) {
 	port = RandomPort()
 
 	// Forward for the CQL port.
@@ -22,15 +22,15 @@ func SetupCassandraContainer(versionTag string) (c ContainerID, ip string, port
 	imageName := fmt.Sprintf("%s:%s", CassandraImageName, versionTag)
 
 	c, ip, err = SetupContainer(imageName, port, 10*time.Second, func() (string, error) {
-		return run("--name", GenerateContainerID(), "-d", "-P", "-p", forward, imageName)
+		return run(append(optionalParams, "--name", GenerateContainerID(), "-d", "-p", forward, imageName)...)
 	})
 	return
 }
 
 // ConnectToCassandra starts a Cassandra image and passes the nodes connection string to the connector callback function.
 // The connection string will match the ip:port pattern, where port is the mapped CQL port.
-func ConnectToCassandra(versionTag string, tries int, delay time.Duration, connector func(url string) bool) (c ContainerID, err error) {
-	c, ip, port, err := SetupCassandraContainer(versionTag)
+func ConnectToCassandra(versionTag string, tries int, delay time.Duration, connector func(url string) bool, optionalParams ...string) (c ContainerID, err error) {
+	c, ip, port, err := SetupCassandraContainer(versionTag, optionalParams...)
 	if err != nil {
 		return c, fmt.Errorf("Could not setup Cassandra container: %v", err)
 	}

docker_integration_test.go

@@ -302,8 +302,13 @@ func TestConnectToCassandra(t *testing.T) {
 	// See: http://stackoverflow.com/questions/34645846/cannot-connect-to-cassandra-docker-with-cqlsh
 	BindDockerToLocalhost = "true"
 
+	env := []string{
+		"-e", "CASSANDRA_RACK=TEST_RACK",
+		"-e", "CASSANDRA_ENDPOINT_SNITCH=GossipingPropertyFileSnitch",
+	}
+
 	// Cassandra takes a while to start up, so we have a longer retry window
-	c, err := ConnectToCassandra("3.7", 15, time.Second*5, func(url string) bool {
+	c, err := ConnectToCassandra("3.7", 20, time.Second*5, func(url string) bool {
 		cluster := gocql.NewCluster(url)
 		cluster.Keyspace = "system"
 		cluster.ProtoVersion = 4 // Required for cassandra 3.x
@@ -314,16 +319,20 @@ func TestConnectToCassandra(t *testing.T) {
 		}
 		defer session.Close()
 
-		// Query one of the system tables as a basic test.
-		it := session.Query("select * from local").Iter()
+		// Verify that the environment property was applied correctly,
+		// and that querying the node works.
+		it := session.Query("select rack from local").Iter()
 		defer it.Close()
 
-		if it.NumRows() == 0 {
-			return false
+		var rackName string
+		for it.Scan(&rackName) {
+			if rackName != "TEST_RACK" {
+				return false
+			}
 		}
 
 		return true
-	})
+	}, env...)
 	assert.Nil(t, err)
 	defer c.KillRemove()
 }