Hella comments

main.go

@@ -10,8 +10,15 @@ import (
 	"time"
 )
 
+// WatchInterval is the duration we should sleep until polling Docker
 var WatchInterval = (5 * time.Second)
 
+// SchedLabel is the string label to search for cron expressions
+var SchedLabel = "cron.schedule"
+
+// ContainerStartJob represents a scheduled container task
+// It contains a reference to a client, the schedule to run on, and the
+// ID of that container that should be started
 type ContainerStartJob struct {
 	Client      *client.Client
 	ContainerID string
@@ -20,6 +27,8 @@ type ContainerStartJob struct {
 	Schedule    string
 }
 
+// Run is executed based on the ContainerStartJob Schedule and starts the
+// container
 func (job ContainerStartJob) Run() {
 	fmt.Println("Starting:", job.Name)
 	err := job.Client.ContainerStart(job.Context, job.ContainerID, types.ContainerStartOptions{})
@@ -28,6 +37,8 @@ func (job ContainerStartJob) Run() {
 	}
 }
 
+// QueryScheduledJobs queries Docker for all containers with a schedule and
+// returns a list of ContainerStartJob records to be scheduled
 func QueryScheduledJobs(cli *client.Client) (jobs []ContainerStartJob) {
 	fmt.Println("Scanning containers for new schedules...")
 	containers, err := cli.ContainerList(context.Background(), types.ContainerListOptions{All: true})
@@ -36,7 +47,7 @@ func QueryScheduledJobs(cli *client.Client) (jobs []ContainerStartJob) {
 	}
 
 	for _, container := range containers {
-		if val, ok := container.Labels["cron.schedule"]; ok {
+		if val, ok := container.Labels[SchedLabel]; ok {
 			jobName := strings.Join(container.Names, "/")
 			jobs = append(jobs, ContainerStartJob{
 				Schedule:    val,
@@ -51,6 +62,8 @@ func QueryScheduledJobs(cli *client.Client) (jobs []ContainerStartJob) {
 	return
 }
 
+// ScheduleJobs accepts a Cron instance and a list of jobs to schedule.
+// It then schedules the provided jobs
 func ScheduleJobs(c *cron.Cron, jobs []ContainerStartJob) {
 	for _, job := range jobs {
 		fmt.Printf("Scheduling %s (%s) with schedule '%s'\n", job.Name, job.ContainerID[:10], job.Schedule)
@@ -59,12 +72,13 @@ func ScheduleJobs(c *cron.Cron, jobs []ContainerStartJob) {
 }
 
 func main() {
+	// Get a Docker Client
 	cli, err := client.NewEnvClient()
 	if err != nil {
 		panic(err)
 	}
 
-	// Create a cron
+	// Create a Cron
 	c := cron.New()
 
 	// Start the loop