From da50191759171eed0166f69668af565f076ed9a0 Mon Sep 17 00:00:00 2001
From: Ian Fijolek <ian@iamthefij.com>
Date: Fri, 3 Aug 2018 17:45:53 -0700
Subject: [PATCH] Come up with a name and watch flag

---
 README.md | 20 ++++++++++----------
 main.go   | 12 +++++++++---
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/README.md b/README.md
index 5521b45..5c53aca 100644
--- a/README.md
+++ b/README.md
@@ -1,28 +1,28 @@
-# docker-batch-scheduler
+# Dockron
 
-WIP for a docker batch scheduler
+A Dead Simple Docker Cron Scheduler
 
 ## Usage
 
-$APPNAME requires access to the Docker, so it may need to be run as root, or, if in a Docker container, need the socket mapped as a volume.
+Dockron requires access to the Docker, so it may need to be run as root, or, if in a Docker container, need the socket mapped as a volume.
 
-### Running $APPNAME
+### Running Dockron
 
 As simple as:
 
-    ./$APPNAME
+    dockron
 
 It will then run in the foreground, periodically checking Docker for containers with labels containing a cron schedule.
 
-$APPNAME will periodically poll Docker for new containers or schedule changes.
+By default, Dockron will periodically poll Docker for new containers or schedule changes every minute. You can specify an interval by using the `-watch` flag.
 
 ### Scheduling a container
 
 First, be sure your container is something that is not long running and will actually exit when complete. This is for batch runs and not keeping a service running. Docker should be able to do that on it's own with a restart policy.
 
-Create your container and add a label in the form `$APPNAME.cron.schedule="* * * * *"`, where the value is a valid cron expression (See the section [Cron Expression Formatting](#cron-expression-formatting)).
+Create your container and add a label in the form `dockron.schedule="* * * * *"`, where the value is a valid cron expression (See the section [Cron Expression Formatting](#cron-expression-formatting)).
 
-$APPNAME will now start that container peridically on the schedule.
+Dockron will now start that container peridically on the schedule.
 
 ### Cron Expression Formatting
 
@@ -30,7 +30,7 @@ For more information on the cron expression parsing, see the docs for [robfig/cr
 
 ## Caveats
 
-$APPNAME is quite simple right now. It does not yet:
+Dockron is quite simple right now. It does not yet:
 
 * Issue any retries
 * Cancel hanging jobs
@@ -40,4 +40,4 @@ I intend to keep it simple as well. It will likely never:
 * Provide any kind of alerting (check out [Minitor](https://git.iamthefij.com/IamTheFij/minitor))
 * Handle job dependencies
 
-Either use a separate tool in conjunction with $APPNAME, or use a more robust scheduler like Tron, or Chronos.
+Either use a separate tool in conjunction with Dockron, or use a more robust scheduler like Tron, or Chronos.
diff --git a/main.go b/main.go
index ddf698d..a9bebd6 100644
--- a/main.go
+++ b/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
@@ -11,10 +12,10 @@ import (
 )
 
 // WatchInterval is the duration we should sleep until polling Docker
-var WatchInterval = (5 * time.Second)
+var DefaultWatchInterval = (1 * time.Minute)
 
 // SchedLabel is the string label to search for cron expressions
-var SchedLabel = "cron.schedule"
+var SchedLabel = "dockron.schedule"
 
 // ContainerStartJob represents a scheduled container task
 // It contains a reference to a client, the schedule to run on, and the
@@ -78,6 +79,11 @@ func main() {
 		panic(err)
 	}
 
+	// Read interval for polling Docker
+	var watchInterval time.Duration
+	flag.DurationVar(&watchInterval, "watch", DefaultWatchInterval, "Interval used to poll Docker for changes")
+	flag.Parse()
+
 	// Create a Cron
 	c := cron.New()
 
@@ -99,6 +105,6 @@ func main() {
 		c.Start()
 
 		// Sleep until the next query time
-		time.Sleep(WatchInterval)
+		time.Sleep(watchInterval)
 	}
 }