Add built-in cron feature.

README.md

@@ -85,6 +85,14 @@ You can try to run in dry-run mode first to see what is going to be purged:
 
     docker exec -t registry-ui /opt/docker-registry-ui -purge-tags -dry-run
 
+Alternatively, you can schedule the purging task with built-in cron service.
+
+```config.yaml
+purge_tags_keep_days: 90
+purge_tags_keep_count: 2
+purge_tags_schedule: '10 3 * * *'
+```
+
 ### Debug mode
 
 To increase http request verbosity, run container with `-e GOREQUEST_DEBUG=1`.

config.yml

@@ -38,7 +38,9 @@ admins: []
 # Debug mode. Affects only templates.
 debug: true
 
-# CLI options.
 # How many days to keep tags but also keep the minimal count provided no matter how old.
 purge_tags_keep_days: 90
 purge_tags_keep_count: 2
+# Schedules to purge tags with cron format. (Only for server mode)
+# Empty string disables this feature.
+purge_tags_schedule: ''

glide.lock

@@ -1,5 +1,5 @@
-hash: d156899e94e2d0d92ed200d5729bec5d0d205b5b98bbf2bd89f7f91c9ed7a518
+hash: fea96c473a02b07acc1d600ee0f71c6a5143f34e5eb04a4c5e3e14378fca46f0
-updated: 2018-05-28T13:28:11.313447+03:00
+updated: 2018-06-09T09:03:51.972089+09:00
 imports:
 - name: github.com/CloudyKit/fastprinter
   version: 74b38d55f37af5d6c05ca11147d616b613a3420e
@@ -36,6 +36,8 @@ imports:
   version: a578a48e8d6ca8b01a3b18314c43c6716bb5f5a3
 - name: github.com/pkg/errors
   version: 816c9085562cd7ee03e7f8188a1cfd942858cded
+- name: github.com/robfig/cron
+  version: b41be1df696709bb6395fe435af20370037c0b4c
 - name: github.com/tidwall/gjson
   version: 01f00f129617a6fe98941fb920d6c760241b54d2
 - name: github.com/tidwall/match

glide.yaml

@@ -14,6 +14,8 @@ import:
 - package: github.com/mattn/go-sqlite3
   version: 1.7.0
 - package: github.com/go-sql-driver/mysql
+- package: github.com/robfig/cron
+  version: ~1.1.0
 testImport:
 - package: github.com/smartystreets/goconvey
   version: 1.6.2

main.go

@@ -15,6 +15,7 @@ import (
 	"github.com/labstack/echo/middleware"
 	"github.com/quiq/docker-registry-ui/events"
 	"github.com/quiq/docker-registry-ui/registry"
+	"github.com/robfig/cron"
 	"github.com/tidwall/gjson"
 	"gopkg.in/yaml.v2"
 )
@@ -35,6 +36,7 @@ type configData struct {
 	Debug                 bool     `yaml:"debug"`
 	PurgeTagsKeepDays     int      `yaml:"purge_tags_keep_days"`
 	PurgeTagsKeepCount    int      `yaml:"purge_tags_keep_count"`
+	PurgeTagsSchedule     string   `yaml:"purge_tags_schedule"`
 }
 
 type template struct {
@@ -84,9 +86,20 @@ func main() {
 
 	// Execute CLI task and exit.
 	if purgeTags {
-		registry.PurgeOldTags(a.client, purgeDryRun, a.config.PurgeTagsKeepDays, a.config.PurgeTagsKeepCount)
+		a.purgeOldTags(purgeDryRun)
 		return
 	}
+	// Schedules to purge tags.
+	if a.config.PurgeTagsSchedule != "" {
+		c := cron.New()
+		task := func() {
+			a.purgeOldTags(purgeDryRun)
+		}
+		if err := c.AddFunc(a.config.PurgeTagsSchedule, task); err != nil {
+			panic(fmt.Errorf("Invalid schedule format: %s", a.config.PurgeTagsSchedule))
+		}
+		c.Start()
+	}
 
 	// Count tags in background.
 	go a.client.CountTags(a.config.CacheRefreshInterval)
@@ -302,3 +315,8 @@ func (a *apiClient) receiveEvents(c echo.Context) error {
 	a.eventListener.ProcessEvents(c.Request())
 	return c.String(http.StatusOK, "OK")
 }
+
+// purgeOldTags purges old tags.
+func (a *apiClient) purgeOldTags(dryRun bool) {
+	registry.PurgeOldTags(a.client, dryRun, a.config.PurgeTagsKeepDays, a.config.PurgeTagsKeepCount)
+}