Jitter watch option

docs/config/index.md

@@ -32,6 +32,7 @@ You can override this using the [`--config` flag or `CONFIG` env var with `serve
     watch:
       workers: 10
       schedule: "0 */6 * * *"
+      jitter: 30s
       firstCheckNotif: false
 
     notif:
@@ -121,6 +122,7 @@ All configuration from file can be transposed into environment variables. As an
     watch:
       workers: 10
       schedule: "0 */6 * * *"
+      jitter: 30s
       firstCheckNotif: false
 
     notif:
@@ -169,6 +171,7 @@ Can be transposed to:
 
     DIUN_WATCH_WORKERS=10
     DIUN_WATCH_SCHEDULE=0 */6 * * *
+    DIUN_WATCH_JITTER=30s
     DIUN_WATCH_FIRSTCHECKNOTIF=false
 
     DIUN_NOTIF_GOTIFY_ENDPOINT=http://gotify.foo.com

docs/config/watch.md

@@ -6,6 +6,7 @@
 watch:
   workers: 10
   schedule: "0 */6 * * *"
+  jitter: 30s
   firstCheckNotif: false
   compareDigest: true
   healthchecks:
@@ -44,6 +45,24 @@ Maximum number of workers that will execute tasks concurrently. (default `10`)
 !!! abstract "Environment variables"
     * `DIUN_WATCH_SCHEDULE`
 
+### `jitter`
+
+Enable time jitter. Prior to executing of a job, cron will sleep a random
+duration in the range from 0 to _jitter_. (default `30s`)
+
+!!! note
+    Only works with `schedule` setting. `0` disables time jitter.
+
+!!! example "Config file"
+    ```yaml
+    watch:
+      schedule: "0 */6 * * *"
+      jitter: 30s
+    ```
+
+!!! abstract "Environment variables"
+    * `DIUN_WATCH_JITTER`
+
 ### `firstCheckNotif`
 
 Send notification at the very first analysis of an image. (default `false`)

docs/install/docker.md

@@ -60,6 +60,7 @@ services:
       - "LOG_JSON=false"
       - "DIUN_WATCH_WORKERS=20"
       - "DIUN_WATCH_SCHEDULE=0 */6 * * *"
+      - "DIUN_WATCH_JITTER=30s"
       - "DIUN_PROVIDERS_DOCKER=true"
     labels:
       - "diun.enable=true"
@@ -82,6 +83,7 @@ docker run -d --name diun \
   -e "LOG_JSON=false" \
   -e "DIUN_WATCH_WORKERS=20" \
   -e "DIUN_WATCH_SCHEDULE=0 */6 * * *" \
+  -e "DIUN_WATCH_JITTER=30s" \
   -e "DIUN_PROVIDERS_DOCKER=true" \
   -v "$(pwd)/data:/data" \
   -v "/var/run/docker.sock:/var/run/docker.sock" \
@@ -153,6 +155,7 @@ services:
       - "LOG_JSON=false"
       - "DIUN_WATCH_WORKERS=20"
       - "DIUN_WATCH_SCHEDULE=0 */6 * * *"
+      - "DIUN_WATCH_JITTER=30s"
       - "DIUN_PROVIDERS_DOCKER=true"
     labels:
       - "diun.enable=true"

docs/providers/docker.md

@@ -31,6 +31,7 @@ services:
       - "LOG_JSON=false"
       - "DIUN_WATCH_WORKERS=20"
       - "DIUN_WATCH_SCHEDULE=0 */6 * * *"
+      - "DIUN_WATCH_JITTER=30s"
       - "DIUN_PROVIDERS_DOCKER=true"
     restart: always
 

docs/providers/kubernetes.md

@@ -82,6 +82,8 @@ spec:
               value: "20"
             - name: DIUN_WATCH_SCHEDULE
               value: "0 */6 * * *"
+            - name: DIUN_WATCH_JITTER
+              value: "30s"
             - name: DIUN_PROVIDERS_KUBERNETES
               value: "true"
           volumeMounts:

docs/providers/swarm.md

@@ -30,6 +30,7 @@ services:
       - "LOG_JSON=false"
       - "DIUN_WATCH_WORKERS=20"
       - "DIUN_WATCH_SCHEDULE=0 */6 * * *"
+      - "DIUN_WATCH_JITTER=30s"
       - "DIUN_PROVIDERS_SWARM=true"
     deploy:
       mode: replicated

docs/usage/basic-example.md

@@ -23,6 +23,7 @@ services:
       - "LOG_JSON=false"
       - "DIUN_WATCH_WORKERS=20"
       - "DIUN_WATCH_SCHEDULE=0 */6 * * *"
+      - "DIUN_WATCH_JITTER=30s"
       - "DIUN_PROVIDERS_DOCKER=true"
       - "DIUN_PROVIDERS_DOCKER_WATCHBYDEFAULT=true"
     restart: always

docs/user-guides/docker-file-providers.md

@@ -28,6 +28,7 @@ services:
       - "LOG_JSON=false"
       - "DIUN_WATCH_WORKERS=20"
       - "DIUN_WATCH_SCHEDULE=0 */6 * * *"
+      - "DIUN_WATCH_JITTER=30s"
       - "DIUN_PROVIDERS_DOCKER=true"
       - "DIUN_PROVIDERS_DOCKER_WATCHBYDEFAULT=true"
       - "DIUN_PROVIDERS_FILE_FILENAME=/custom-images.yml"

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/bmatcuk/doublestar/v3 v3.0.0
 	github.com/containerd/containerd v1.6.14
 	github.com/containers/image/v5 v5.23.1
+	github.com/crazy-max/cron/v3 v3.1.1
 	github.com/crazy-max/gohealthchecks v0.3.0
 	github.com/crazy-max/gonfig v0.6.0
 	github.com/docker/docker v20.10.18+incompatible
@@ -32,7 +33,6 @@ require (
 	github.com/panjf2000/ants/v2 v2.7.1
 	github.com/pkg/errors v0.9.1
 	github.com/pkg/profile v1.7.0
-	github.com/robfig/cron/v3 v3.0.1
 	github.com/rs/zerolog v1.28.0
 	github.com/russross/blackfriday/v2 v2.1.0
 	github.com/sirupsen/logrus v1.9.0

go.sum

@@ -265,6 +265,8 @@ github.com/coreos/pkg v0.0.0-20160727233714-3ac0863d7acf/go.mod h1:E3G3o1h8I7cfc
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
+github.com/crazy-max/cron/v3 v3.1.1 h1:8tsAXjV522daYSaN6/Mb/Nh8X/Ez+nedU0KuPV98rNU=
+github.com/crazy-max/cron/v3 v3.1.1/go.mod h1:yexi3kKoh3GcnmRCppyJKsvYIBWzDVaym0dwNWo+zdg=
 github.com/crazy-max/gohealthchecks v0.3.0 h1:mXtTsOinEOcvRcnT3ayRkxGdK18LfrFOWE/gFpfzEI4=
 github.com/crazy-max/gohealthchecks v0.3.0/go.mod h1:gkT8QSdEXZJahyswdTGDbd+q20fWm0DmWW7TWBNtgJg=
 github.com/crazy-max/gonfig v0.6.0 h1:CwP+x1gfor4Ze8lLQKkZw/DOQEMVgwBcoocTYLo3c4A=
@@ -762,8 +764,6 @@ github.com/prometheus/procfs v0.6.0/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
-github.com/robfig/cron/v3 v3.0.1 h1:WdRxkvbJztn8LMz/QEvLN5sBU+xKpSqwwUO1Pjr4qDs=
-github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzGIFLtro=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=

internal/app/diun.go

@@ -6,6 +6,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/crazy-max/cron/v3"
 	"github.com/crazy-max/diun/v4/internal/config"
 	"github.com/crazy-max/diun/v4/internal/db"
 	"github.com/crazy-max/diun/v4/internal/grpc"
@@ -22,7 +23,6 @@ import (
 	"github.com/hako/durafmt"
 	"github.com/panjf2000/ants/v2"
 	"github.com/pkg/errors"
-	"github.com/robfig/cron/v3"
 	"github.com/rs/zerolog/log"
 )
 
@@ -110,7 +110,7 @@ func (di *Diun) Start() error {
 	if len(di.cfg.Watch.Schedule) == 0 {
 		return nil
 	}
-	di.jobID, err = di.cron.AddJob(di.cfg.Watch.Schedule, di)
+	di.jobID, err = di.cron.AddJobWithJitter(di.cfg.Watch.Schedule, di, *di.cfg.Watch.Jitter)
 	if err != nil {
 		return err
 	}

internal/config/config_test.go

@@ -52,6 +52,7 @@ func TestLoadFile(t *testing.T) {
 				Watch: &model.Watch{
 					Workers:         100,
 					Schedule:        "*/30 * * * *",
+					Jitter:          utl.NewDuration(30 * time.Second),
 					FirstCheckNotif: utl.NewTrue(),
 					CompareDigest:   utl.NewTrue(),
 					Healthchecks: &model.Healthchecks{

internal/config/fixtures/config.test.yml

@@ -4,6 +4,7 @@ db:
 watch:
   workers: 100
   schedule: "*/30 * * * *"
+  jitter: 30s
   firstCheckNotif: true
   compareDigest: true
   healthchecks:

internal/config/fixtures/config.validate.yml

@@ -4,6 +4,7 @@ db:
 watch:
   workers: 100
   schedule: "*/30 * * * *"
+  jitter: 30s
   firstCheckNotif: false
   compareDigest: true
   healthchecks:

internal/model/watch.go

@@ -1,16 +1,19 @@
 package model
 
 import (
+	"time"
+
 	"github.com/crazy-max/diun/v4/pkg/utl"
 )
 
 // Watch holds data necessary for watch configuration
 type Watch struct {
-	Workers         int           `yaml:"workers,omitempty" json:"workers,omitempty" validate:"required,min=1"`
-	Schedule        string        `yaml:"schedule,omitempty" json:"schedule,omitempty"`
-	FirstCheckNotif *bool         `yaml:"firstCheckNotif,omitempty" json:"firstCheckNotif,omitempty" validate:"required"`
-	CompareDigest   *bool         `yaml:"compareDigest,omitempty" json:"compareDigest,omitempty" validate:"required"`
-	Healthchecks    *Healthchecks `yaml:"healthchecks,omitempty" json:"healthchecks,omitempty"`
+	Workers         int            `yaml:"workers,omitempty" json:"workers,omitempty" validate:"required,min=1"`
+	Schedule        string         `yaml:"schedule,omitempty" json:"schedule,omitempty"`
+	Jitter          *time.Duration `yaml:"jitter,omitempty" json:"jitter,omitempty" validate:"required"`
+	FirstCheckNotif *bool          `yaml:"firstCheckNotif,omitempty" json:"firstCheckNotif,omitempty" validate:"required"`
+	CompareDigest   *bool          `yaml:"compareDigest,omitempty" json:"compareDigest,omitempty" validate:"required"`
+	Healthchecks    *Healthchecks  `yaml:"healthchecks,omitempty" json:"healthchecks,omitempty"`
 }
 
 // GetDefaults gets the default values
@@ -23,6 +26,7 @@ func (s *Watch) GetDefaults() *Watch {
 // SetDefaults sets the default values
 func (s *Watch) SetDefaults() {
 	s.Workers = 10
+	s.Jitter = utl.NewDuration(30 * time.Second)
 	s.FirstCheckNotif = utl.NewFalse()
 	s.CompareDigest = utl.NewTrue()
 }

test/docker2/diun.yml

@@ -1,6 +1,7 @@
 watch:
   workers: 20
   schedule: "0 */6 * * *"
+  jitter: 5m
 
 providers:
   docker:

test/docker3/diun.yml

@@ -1,6 +1,7 @@
 watch:
   workers: 20
   schedule: "0 */6 * * *"
+  jitter: 0
 
 providers:
   docker: