PLT-6916: Redesign the jobs package and Jobserver. (#6733)

This commit redesigns the jobserver to be based around an architecture
of "workers", which carry out jobs of a particular type, and "jobs"
which are a unit of work carried by a particular worker. It also
introduces "schedulers" which are responsible for scheduling jobs of a
particular type automatically (jobs can also be scheduled manually when
apropriate).

Workers may be run many times, either in instances of the platform
binary, or the standalone jobserver binary. In any mattermost cluster,
only one instance of platform OR jobserver must run the schedulers. At
the moment this is controlled by a config variable, but in future will
be controlled through the cluster leader election process.

model/client4.go

@@ -2790,22 +2790,22 @@ func (c *Client4) OpenGraph(url string) (map[string]string, *Response) {
 
 // Jobs Section
 
-// GetJobStatus gets the status of a single job.
-func (c *Client4) GetJobStatus(id string) (*JobStatus, *Response) {
+// GetJob gets a single job.
+func (c *Client4) GetJob(id string) (*Job, *Response) {
 	if r, err := c.DoApiGet(c.GetJobsRoute()+fmt.Sprintf("/%v/status", id), ""); err != nil {
 		return nil, BuildErrorResponse(r, err)
 	} else {
 		defer closeBody(r)
-		return JobStatusFromJson(r.Body), BuildResponse(r)
+		return JobFromJson(r.Body), BuildResponse(r)
 	}
 }
 
-// GetJobStatusesByType gets the status of all jobs of a given type, sorted with the job that most recently started first.
-func (c *Client4) GetJobStatusesByType(jobType string, page int, perPage int) ([]*JobStatus, *Response) {
+// GetJobsByType gets all jobs of a given type, sorted with the job that most recently started first.
+func (c *Client4) GetJobsByType(jobType string, page int, perPage int) ([]*Job, *Response) {
 	if r, err := c.DoApiGet(c.GetJobsRoute()+fmt.Sprintf("/type/%v/statuses?page=%v&per_page=%v", jobType, page, perPage), ""); err != nil {
 		return nil, BuildErrorResponse(r, err)
 	} else {
 		defer closeBody(r)
-		return JobStatusesFromJson(r.Body), BuildResponse(r)
+		return JobsFromJson(r.Body), BuildResponse(r)
 	}
 }

model/config.go

@@ -436,6 +436,11 @@ type DataRetentionSettings struct {
 	Enable *bool
 }
 
+type JobSettings struct {
+	RunJobs      *bool
+	RunScheduler *bool
+}
+
 type Config struct {
 	ServiceSettings       ServiceSettings
 	TeamSettings          TeamSettings
@@ -462,6 +467,7 @@ type Config struct {
 	WebrtcSettings        WebrtcSettings
 	ElasticSearchSettings ElasticSearchSettings
 	DataRetentionSettings DataRetentionSettings
+	JobSettings           JobSettings
 }
 
 func (o *Config) ToJson() string {
@@ -1380,6 +1386,16 @@ func (o *Config) SetDefaults() {
 		*o.DataRetentionSettings.Enable = false
 	}
 
+	if o.JobSettings.RunJobs == nil {
+		o.JobSettings.RunJobs = new(bool)
+		*o.JobSettings.RunJobs = true
+	}
+
+	if o.JobSettings.RunScheduler == nil {
+		o.JobSettings.RunScheduler = new(bool)
+		*o.JobSettings.RunScheduler = true
+	}
+
 	o.defaultWebrtcSettings()
 }
 

model/job.go

@@ -3,7 +3,84 @@
 
 package model
 
-type Job interface {
+import (
+	"encoding/json"
+	"io"
+)
+
+const (
+	JOB_TYPE_DATA_RETENTION  = "data_retention"
+	JOB_TYPE_SEARCH_INDEXING = "search_indexing"
+
+	JOB_STATUS_PENDING          = "pending"
+	JOB_STATUS_IN_PROGRESS      = "in_progress"
+	JOB_STATUS_SUCCESS          = "success"
+	JOB_STATUS_ERROR            = "error"
+	JOB_STATUS_CANCEL_REQUESTED = "cancel_requested"
+	JOB_STATUS_CANCELED         = "canceled"
+)
+
+type Job struct {
+	Id             string                 `json:"id"`
+	Type           string                 `json:"type"`
+	Priority       int64                  `json:"priority"`
+	CreateAt       int64                  `json:"create_at"`
+	StartAt        int64                  `json:"start_at"`
+	LastActivityAt int64                  `json:"last_activity_at"`
+	Status         string                 `json:"status"`
+	Progress       int64                  `json:"progress"`
+	Data           map[string]interface{} `json:"data"`
+}
+
+func (js *Job) ToJson() string {
+	if b, err := json.Marshal(js); err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}
+
+func JobFromJson(data io.Reader) *Job {
+	var status Job
+	if err := json.NewDecoder(data).Decode(&status); err == nil {
+		return &status
+	} else {
+		return nil
+	}
+}
+
+func JobsToJson(jobs []*Job) string {
+	if b, err := json.Marshal(jobs); err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}
+
+func JobsFromJson(data io.Reader) []*Job {
+	var jobs []*Job
+	if err := json.NewDecoder(data).Decode(&jobs); err == nil {
+		return jobs
+	} else {
+		return nil
+	}
+}
+
+func (js *Job) DataToJson() string {
+	if b, err := json.Marshal(js.Data); err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}
+
+type Worker interface {
+	Run()
+	Stop()
+	JobChannel() chan<- Job
+}
+
+type Scheduler interface {
 	Run()
 	Stop()
 }

model/job_status.go

@@ -1,59 +0,0 @@
-// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
-// See License.txt for license information.
-
-package model
-
-import (
-	"encoding/json"
-	"io"
-)
-
-const (
-	JOB_TYPE_DATA_RETENTION  = "data_retention"
-	JOB_TYPE_SEARCH_INDEXING = "search_indexing"
-)
-
-type JobStatus struct {
-	Id                 string                 `json:"id"`
-	Type               string                 `json:"type"`
-	StartAt            int64                  `json:"start_at"`
-	LastActivityAt     int64                  `json:"last_activity_at"`
-	LastRunStartedAt   int64                  `json:"last_run_started_at"`
-	LastRunCompletedAt int64                  `json:"last_run_completed_at"`
-	Status             string                 `json:"status"`
-	Data               map[string]interface{} `json:"data"`
-}
-
-func (js *JobStatus) ToJson() string {
-	if b, err := json.Marshal(js); err != nil {
-		return ""
-	} else {
-		return string(b)
-	}
-}
-
-func JobStatusFromJson(data io.Reader) *JobStatus {
-	var status JobStatus
-	if err := json.NewDecoder(data).Decode(&status); err == nil {
-		return &status
-	} else {
-		return nil
-	}
-}
-
-func JobStatusesToJson(statuses []*JobStatus) string {
-	if b, err := json.Marshal(statuses); err != nil {
-		return ""
-	} else {
-		return string(b)
-	}
-}
-
-func JobStatusesFromJson(data io.Reader) []*JobStatus {
-	var statuses []*JobStatus
-	if err := json.NewDecoder(data).Decode(&statuses); err == nil {
-		return statuses
-	} else {
-		return nil
-	}
-}