Add command topic message ttl. (streamnative/pulsarctl#246) (apache#348)

Add command topic message ttl:
* pulsarctl topics get-message-ttl [topic]
* pulsarctl topics set-message-ttl [topic] -t [seconds] 
* pulsarctl topics remove-message-ttl [topic]

pulsaradmin/pkg/cli/client.go

@@ -277,6 +277,28 @@ func (c *Client) PostWithMultiPart(endpoint string, in interface{}, body io.Read
 	return nil
 }
 
+func (c *Client) PostWithQueryParams(endpoint string, params map[string]string) error {
+	req, err := c.newRequest(http.MethodPost, endpoint)
+	if err != nil {
+		return err
+	}
+	if params != nil {
+		query := req.url.Query()
+		for k, v := range params {
+			query.Add(k, v)
+		}
+		req.params = query
+	}
+	// nolint
+	resp, err := checkSuccessful(c.doRequest(req))
+	if err != nil {
+		return err
+	}
+	defer safeRespClose(resp)
+
+	return nil
+}
+
 type request struct {
 	method      string
 	contentType string

pulsaradmin/pkg/pulsar/topic.go

@@ -98,6 +98,15 @@ type Topics interface {
 
 	// CompactStatus checks the status of an ongoing compaction for a topic
 	CompactStatus(utils.TopicName) (utils.LongRunningProcessStatus, error)
+
+	// GetMessageTTL Get the message TTL for a topic
+	GetMessageTTL(utils.TopicName) (int, error)
+
+	// SetMessageTTL Set the message TTL for a topic
+	SetMessageTTL(utils.TopicName, int) error
+
+	// RemoveMessageTTL Remove the message TTL for a topic
+	RemoveMessageTTL(utils.TopicName) error
 }
 
 type topics struct {
@@ -301,3 +310,26 @@ func (t *topics) CompactStatus(topic utils.TopicName) (utils.LongRunningProcessS
 	err := t.pulsar.Client.Get(endpoint, &status)
 	return status, err
 }
+
+func (t *topics) GetMessageTTL(topic utils.TopicName) (int, error) {
+	var ttl int
+	endpoint := t.pulsar.endpoint(t.basePath, topic.GetRestPath(), "messageTTL")
+	err := t.pulsar.Client.Get(endpoint, &ttl)
+	return ttl, err
+}
+
+func (t *topics) SetMessageTTL(topic utils.TopicName, messageTTL int) error {
+	endpoint := t.pulsar.endpoint(t.basePath, topic.GetRestPath(), "messageTTL")
+	var params = make(map[string]string)
+	params["messageTTL"] = strconv.Itoa(messageTTL)
+	err := t.pulsar.Client.PostWithQueryParams(endpoint, params)
+	return err
+}
+
+func (t *topics) RemoveMessageTTL(topic utils.TopicName) error {
+	endpoint := t.pulsar.endpoint(t.basePath, topic.GetRestPath(), "messageTTL")
+	var params = make(map[string]string)
+	params["messageTTL"] = strconv.Itoa(0)
+	err := t.pulsar.Client.DeleteWithQueryParams(endpoint, params)
+	return err
+}