Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/jobs/base_workers.go

@@ -0,0 +1,116 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package jobs
+
+import (
+	"net/http"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/mattermost/mattermost-server/v6/server/platform/shared/mlog"
+)
+
+type SimpleWorker struct {
+	name      string
+	stop      chan bool
+	stopped   chan bool
+	jobs      chan model.Job
+	jobServer *JobServer
+	execute   func(job *model.Job) error
+	isEnabled func(cfg *model.Config) bool
+}
+
+func NewSimpleWorker(name string, jobServer *JobServer, execute func(job *model.Job) error, isEnabled func(cfg *model.Config) bool) *SimpleWorker {
+	worker := SimpleWorker{
+		name:      name,
+		stop:      make(chan bool, 1),
+		stopped:   make(chan bool, 1),
+		jobs:      make(chan model.Job),
+		jobServer: jobServer,
+		execute:   execute,
+		isEnabled: isEnabled,
+	}
+	return &worker
+}
+
+func (worker *SimpleWorker) Run() {
+	mlog.Debug("Worker started", mlog.String("worker", worker.name))
+
+	defer func() {
+		mlog.Debug("Worker finished", mlog.String("worker", worker.name))
+		worker.stopped <- true
+	}()
+
+	for {
+		select {
+		case <-worker.stop:
+			mlog.Debug("Worker received stop signal", mlog.String("worker", worker.name))
+			return
+		case job := <-worker.jobs:
+			mlog.Debug("Worker received a new candidate job.", mlog.String("worker", worker.name))
+			worker.DoJob(&job)
+		}
+	}
+}
+
+func (worker *SimpleWorker) Stop() {
+	mlog.Debug("Worker stopping", mlog.String("worker", worker.name))
+	worker.stop <- true
+	<-worker.stopped
+}
+
+func (worker *SimpleWorker) JobChannel() chan<- model.Job {
+	return worker.jobs
+}
+
+func (worker *SimpleWorker) IsEnabled(cfg *model.Config) bool {
+	return worker.isEnabled(cfg)
+}
+
+func (worker *SimpleWorker) DoJob(job *model.Job) {
+	if claimed, err := worker.jobServer.ClaimJob(job); err != nil {
+		mlog.Warn("SimpleWorker experienced an error while trying to claim job",
+			mlog.String("worker", worker.name),
+			mlog.String("job_id", job.Id),
+			mlog.Err(err))
+		return
+	} else if !claimed {
+		return
+	}
+
+	var appErr *model.AppError
+	// We get the job again because ClaimJob changes the job status.
+	job, appErr = worker.jobServer.GetJob(job.Id)
+	if appErr != nil {
+		mlog.Error("SimpleWorker: job execution error", mlog.String("worker", worker.name), mlog.String("job_id", job.Id), mlog.Err(appErr))
+		worker.setJobError(job, appErr)
+	}
+
+	err := worker.execute(job)
+	if err != nil {
+		mlog.Error("SimpleWorker: job execution error", mlog.String("worker", worker.name), mlog.String("job_id", job.Id), mlog.Err(err))
+		worker.setJobError(job, model.NewAppError("DoJob", "app.job.error", nil, "", http.StatusInternalServerError).Wrap(err))
+		return
+	}
+
+	mlog.Info("SimpleWorker: Job is complete", mlog.String("worker", worker.name), mlog.String("job_id", job.Id))
+	worker.setJobSuccess(job)
+}
+
+func (worker *SimpleWorker) setJobSuccess(job *model.Job) {
+	if err := worker.jobServer.SetJobProgress(job, 100); err != nil {
+		mlog.Error("Worker: Failed to update progress for job", mlog.String("worker", worker.name), mlog.String("job_id", job.Id), mlog.Err(err))
+		worker.setJobError(job, err)
+	}
+
+	if err := worker.jobServer.SetJobSuccess(job); err != nil {
+		mlog.Error("SimpleWorker: Failed to set success for job", mlog.String("worker", worker.name), mlog.String("job_id", job.Id), mlog.Err(err))
+		worker.setJobError(job, err)
+	}
+}
+
+func (worker *SimpleWorker) setJobError(job *model.Job, appError *model.AppError) {
+	if err := worker.jobServer.SetJobError(job, appError); err != nil {
+		mlog.Error("SimpleWorker: Failed to set job error", mlog.String("worker", worker.name), mlog.String("job_id", job.Id), mlog.Err(err))
+	}
+}