Fix Task List API to accept strings as TaskIds

In the Java source, task identification is represented by the `TaskId`
class. That class contains a `nodeId` (a `string`) and a numerical `id`
(a `long`). In the Tasks API, these two get mixed. Sometimes the
`TaskId` is used, which is a concatenation of `nodeId`, a colon, and
the numerical `id`, which yields a `string`. Sometimes, though,
especially in the response structures, the `nodeId` and `id` get
returned individually. So we must look at each of the response
structures in the Java source to find out the correct type used in the
response.

This commit now changes the Task List API to accept task ids as a
string, because that's what the REST API spec defines. We also add the
`GroupBy` property, and some missing fields in the response structures.

We also update Travis configuration and `run-es.sh` to Elasticsearch 6.1.2.

.travis.yml

@@ -12,4 +12,4 @@ services:
   - docker
 before_install:
   - sudo sysctl -w vm.max_map_count=262144
-  - docker run -d --rm -p 9200:9200  -e "http.host=0.0.0.0" -e "transport.host=127.0.0.1" -e "bootstrap.memory_lock=true" -e "ES_JAVA_OPTS=-Xms1g -Xmx1g" docker.elastic.co/elasticsearch/elasticsearch:6.1.1 elasticsearch -Expack.security.enabled=false -Enetwork.host=_local_,_site_ -Enetwork.publish_host=_local_
+  - docker run -d --rm -p 9200:9200  -e "http.host=0.0.0.0" -e "transport.host=127.0.0.1" -e "bootstrap.memory_lock=true" -e "ES_JAVA_OPTS=-Xms1g -Xmx1g" docker.elastic.co/elasticsearch/elasticsearch:6.1.2 elasticsearch -Expack.security.enabled=false -Enetwork.host=_local_,_site_ -Enetwork.publish_host=_local_

run-es.sh

@@ -1,3 +1,3 @@
 #!/bin/sh
-VERSION=${VERSION:=6.1.1}
+VERSION=${VERSION:=6.1.2}
 docker run --rm -p 9200:9200  -e "http.host=0.0.0.0" -e "transport.host=127.0.0.1" -e "bootstrap.memory_lock=true" -e "ES_JAVA_OPTS=-Xms1g -Xmx1g" docker.elastic.co/elasticsearch/elasticsearch:$VERSION elasticsearch -Expack.security.enabled=false -Enetwork.host=_local_,_site_ -Enetwork.publish_host=_local_

tasks_list.go

@@ -15,33 +15,31 @@ import (
 
 // TasksListService retrieves the list of currently executing tasks
 // on one ore more nodes in the cluster. It is part of the Task Management API
-// documented at http://www.elastic.co/guide/en/elasticsearch/reference/5.2/tasks-list.html.
+// documented at https://www.elastic.co/guide/en/elasticsearch/reference/6.0/tasks.html.
 //
 // It is supported as of Elasticsearch 2.3.0.
 type TasksListService struct {
 	client            *Client
 	pretty            bool
-	taskId            []int64
+	taskId            []string
 	actions           []string
 	detailed          *bool
 	nodeId            []string
 	parentNode        string
-	parentTask        *int64
+	parentTaskId      *string
 	waitForCompletion *bool
+	groupBy           string
 }
 
 // NewTasksListService creates a new TasksListService.
 func NewTasksListService(client *Client) *TasksListService {
 	return &TasksListService{
-		client:  client,
-		taskId:  make([]int64, 0),
-		actions: make([]string, 0),
-		nodeId:  make([]string, 0),
+		client: client,
 	}
 }
 
 // TaskId indicates to returns the task(s) with specified id(s).
-func (s *TasksListService) TaskId(taskId ...int64) *TasksListService {
+func (s *TasksListService) TaskId(taskId ...string) *TasksListService {
 	s.taskId = append(s.taskId, taskId...)
 	return s
 }
@@ -72,9 +70,9 @@ func (s *TasksListService) ParentNode(parentNode string) *TasksListService {
 	return s
 }
 
-// ParentTask returns tasks with specified parent task id. Set to -1 to return all.
-func (s *TasksListService) ParentTask(parentTask int64) *TasksListService {
-	s.parentTask = &parentTask
+// ParentTaskId returns tasks with specified parent task id (node_id:task_number). Set to -1 to return all.
+func (s *TasksListService) ParentTaskId(parentTaskId string) *TasksListService {
+	s.parentTaskId = &parentTaskId
 	return s
 }
 
@@ -85,6 +83,13 @@ func (s *TasksListService) WaitForCompletion(waitForCompletion bool) *TasksListS
 	return s
 }
 
+// GroupBy groups tasks by nodes or parent/child relationships.
+// As of now, it can either be "nodes" (default) or "parents".
+func (s *TasksListService) GroupBy(groupBy string) *TasksListService {
+	s.groupBy = groupBy
+	return s
+}
+
 // Pretty indicates that the JSON response be indented and human readable.
 func (s *TasksListService) Pretty(pretty bool) *TasksListService {
 	s.pretty = pretty
@@ -97,12 +102,8 @@ func (s *TasksListService) buildURL() (string, url.Values, error) {
 	var err error
 	var path string
 	if len(s.taskId) > 0 {
-		var tasks []string
-		for _, taskId := range s.taskId {
-			tasks = append(tasks, fmt.Sprintf("%d", taskId))
-		}
 		path, err = uritemplates.Expand("/_tasks/{task_id}", map[string]string{
-			"task_id": strings.Join(tasks, ","),
+			"task_id": strings.Join(s.taskId, ","),
 		})
 	} else {
 		path = "/_tasks"
@@ -128,12 +129,15 @@ func (s *TasksListService) buildURL() (string, url.Values, error) {
 	if s.parentNode != "" {
 		params.Set("parent_node", s.parentNode)
 	}
-	if s.parentTask != nil {
-		params.Set("parent_task", fmt.Sprintf("%v", *s.parentTask))
+	if s.parentTaskId != nil {
+		params.Set("parent_task_id", *s.parentTaskId)
 	}
 	if s.waitForCompletion != nil {
 		params.Set("wait_for_completion", fmt.Sprintf("%v", *s.waitForCompletion))
 	}
+	if s.groupBy != "" {
+		params.Set("group_by", s.groupBy)
+	}
 	return path, params, nil
 }
 
@@ -182,7 +186,7 @@ type TasksListResponse struct {
 }
 
 type TaskOperationFailure struct {
-	TaskId int64         `json:"task_id"`
+	TaskId int64         `json:"task_id"` // this is a long in the Java source
 	NodeId string        `json:"node_id"`
 	Status string        `json:"status"`
 	Reason *ErrorDetails `json:"reason"`
@@ -198,14 +202,16 @@ type DiscoveryNode struct {
 	TransportAddress string                 `json:"transport_address"`
 	Host             string                 `json:"host"`
 	IP               string                 `json:"ip"`
+	Roles            []string               `json:"roles"` // "master", "data", or "ingest"
 	Attributes       map[string]interface{} `json:"attributes"`
 	// Tasks returns the tasks by its id (as a string).
 	Tasks map[string]*TaskInfo `json:"tasks"`
 }
 
+// TaskInfo represents information about a currently running task.
 type TaskInfo struct {
 	Node               string      `json:"node"`
-	Id                 int64       `json:"id"` // the task id
+	Id                 int64       `json:"id"` // the task id (yes, this is a long in the Java source)
 	Type               string      `json:"type"`
 	Action             string      `json:"action"`
 	Status             interface{} `json:"status"`      // has separate implementations of Task.Status in Java for reindexing, replication, and "RawTaskStatus"

tasks_list_test.go

@@ -13,19 +13,19 @@ func TestTasksListBuildURL(t *testing.T) {
 	client := setupTestClient(t)
 
 	tests := []struct {
-		TaskId   []int64
+		TaskId   []string
 		Expected string
 	}{
 		{
-			[]int64{},
+			[]string{},
 			"/_tasks",
 		},
 		{
-			[]int64{42},
+			[]string{"42"},
 			"/_tasks/42",
 		},
 		{
-			[]int64{42, 37},
+			[]string{"42", "37"},
 			"/_tasks/42%2C37",
 		},
 	}