Cronicle

Multi-server task scheduler and cron replacement with a web-based UI. Cronicle lets you create and manage scheduled jobs from a browser — set cron expressions, set concurrency limits, view live logs, receive email alerts, and review job history. Job data and state are stored in flat JSON files on a persistent volume.

Key Features

Web UI — browser-based job management with live log streaming
Cron replacement — cron-compatible scheduling with visual editor
Email notifications — SMTP alerts for job success, failure, and warnings
Session encryption — auto-generated secret_key stored in a Kubernetes Secret
Job memory limits — configurable per-job memory cap
Concurrency control — configurable maximum concurrent jobs per server
Persistent storage — PVC for job data, history, and state JSON files

Installation

HTTPS repository:

helm repo add helmforge https://repo.helmforge.dev
helm repo update
helm install cronicle helmforge/cronicle

OCI registry:

helm install cronicle oci://ghcr.io/helmforgedev/helm/cronicle

Deployment Examples

# values.yaml — Cronicle with public URL and persistence
cronicle:
  baseUrl: 'https://cronicle.example.com'

persistence:
  enabled: true
  size: 5Gi

ingress:
  enabled: true
  ingressClassName: traefik
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-prod
  hosts:
    - host: cronicle.example.com
      paths:
        - path: /
          pathType: Prefix
  tls:
    - secretName: cronicle-tls
      hosts:
        - cronicle.example.com

# values.yaml — Cronicle with SMTP notifications
cronicle:
  baseUrl: 'https://cronicle.example.com'
  emailFrom: 'cronicle@example.com'
  smtpHostname: 'smtp.example.com'
  extraEnv:
    # SMTP port (default is 25; use 587 for STARTTLS)
    - name: CRONICLE_smtp_port
      value: '587'
    # SMTP authentication (if required)
    - name: CRONICLE_smtp_secure
      value: 'true'

persistence:
  enabled: true
  size: 5Gi

ingress:
  enabled: true
  ingressClassName: traefik
  hosts:
    - host: cronicle.example.com
      paths:
        - path: /
          pathType: Prefix

# values.yaml — Production setup with job limits and existing secret
cronicle:
  baseUrl: 'https://cronicle.example.com'
  emailFrom: 'cronicle@example.com'
  smtpHostname: 'smtp.example.com'
  maxJobs: 10
  jobMemoryMax: 2147483648 # 2 GB per job

secret:
  create: false
  existingSecret: cronicle-secret # must contain key: secret_key

resources:
  requests:
    memory: 256Mi
    cpu: 100m
  limits:
    memory: 1Gi
    cpu: 1000m

persistence:
  enabled: true
  size: 10Gi

ingress:
  enabled: true
  ingressClassName: traefik
  hosts:
    - host: cronicle.example.com
      paths:
        - path: /
          pathType: Prefix

Configuration Reference

Core

Parameter	Type	Default	Description
`nameOverride`	string	`""`	Override the chart name.
`fullnameOverride`	string	`""`	Override the full release name.
`commonLabels`	object	`{}`	Extra labels added to all resources.

Image

Parameter	Type	Default	Description
`image.repository`	string	`docker.io/soulteary/cronicle`	Cronicle container image.
`image.tag`	string	`"0.9.80"`	Image tag.
`image.pullPolicy`	string	`IfNotPresent`	Image pull policy.
`imagePullSecrets`	array	`[]`	Pull secrets for private registries.

Cronicle Configuration

Parameter	Type	Default	Description
`cronicle.port`	integer	`3012`	Internal HTTP port for the Cronicle web UI.
`cronicle.discoveryPort`	integer	`3014`	UDP auto-discovery port for multi-server setups.
`cronicle.discoveryEnabled`	boolean	`false`	Enable UDP auto-discovery Service port.
`cronicle.baseUrl`	string	`http://localhost:3012`	Public base URL. Must be updated for notifications and UI links to work.
`cronicle.emailFrom`	string	`cronicle@localhost`	Email sender address for job notifications.
`cronicle.smtpHostname`	string	`localhost`	SMTP server hostname for notifications.
`cronicle.jobMemoryMax`	integer	`1073741824`	Maximum memory per job in bytes (default 1 GB = `1073741824`).
`cronicle.maxJobs`	integer	`0`	Maximum concurrent jobs. `0` means unlimited.
`cronicle.extraEnv`	array	`[]`	Extra environment variables for SMTP auth and advanced configuration.

baseUrl defaults to localhost — update before deploying

The default cronicle.baseUrl is http://localhost:3012. If not changed, email notification links and some internal UI references will point to localhost instead of your actual instance. Set this to your public URL (e.g. https://cronicle.example.com) before first deployment.

Limit maxJobs in production to avoid node overload

With maxJobs: 0 (unlimited), Cronicle will run as many concurrent jobs as are scheduled, which can saturate the node’s CPU and memory. For production use, set maxJobs to a value that matches your available resources — typically 5–10 for a standard pod with 1–2 CPU cores.

Session Secret

Parameter	Type	Default	Description
`secret.create`	boolean	`true`	Auto-generate a `secret_key` for Cronicle session encryption.
`secret.existingSecret`	string	`""`	Use an existing Kubernetes Secret (must contain key `secret_key`).

Preserve the secret_key across reinstalls

Cronicle uses secret_key to sign user sessions. If the Helm release is deleted and reinstalled with secret.create: true, a new key is generated and all existing sessions are invalidated. For stable deployments, create the Secret manually and reference it with secret.existingSecret.

Persistence

Cronicle stores all job definitions, schedules, history, and state in flat JSON files under /opt/cronicle/data. No external database is required.

Parameter	Type	Default	Description
`persistence.enabled`	boolean	`true`	Enable a PVC for `/opt/cronicle/data`.
`persistence.size`	string	`5Gi`	PVC size.
`persistence.storageClass`	string	`""`	StorageClass for the PVC.
`persistence.accessModes`	array	`["ReadWriteOnce"]`	PVC access modes.
`persistence.existingClaim`	string	`""`	Use an existing PVC instead of creating one.

Service

Parameter	Type	Default	Description
`service.type`	string	`ClusterIP`	Kubernetes service type.
`service.port`	integer	`80`	Service port exposed to the cluster.
`service.annotations`	object	`{}`	Annotations for the Service.

Ingress

Parameter	Type	Default	Description
`ingress.enabled`	boolean	`false`	Enable an Ingress resource.
`ingress.ingressClassName`	string	`traefik`	Ingress class name.
`ingress.annotations`	object	`{}`	Annotations for the Ingress (e.g. cert-manager).
`ingress.hosts`	array	`[]`	Ingress host and path rules.
`ingress.tls`	array	`[]`	TLS configuration (secret name and hosts).

Probes

Parameter	Type	Default	Description
`probes.startup.enabled`	boolean	`true`	Enable startup probe.
`probes.startup.initialDelaySeconds`	integer	`5`	Startup probe initial delay.
`probes.startup.periodSeconds`	integer	`5`	Startup probe period.
`probes.startup.timeoutSeconds`	integer	`3`	Startup probe timeout.
`probes.startup.failureThreshold`	integer	`30`	Startup probe failure threshold.
`probes.liveness.enabled`	boolean	`true`	Enable liveness probe.
`probes.liveness.initialDelaySeconds`	integer	`0`	Liveness probe initial delay.
`probes.liveness.periodSeconds`	integer	`15`	Liveness probe period.
`probes.liveness.timeoutSeconds`	integer	`5`	Liveness probe timeout.
`probes.liveness.failureThreshold`	integer	`3`	Liveness probe failure threshold.
`probes.readiness.enabled`	boolean	`true`	Enable readiness probe.
`probes.readiness.initialDelaySeconds`	integer	`0`	Readiness probe initial delay.
`probes.readiness.periodSeconds`	integer	`10`	Readiness probe period.
`probes.readiness.timeoutSeconds`	integer	`5`	Readiness probe timeout.
`probes.readiness.failureThreshold`	integer	`3`	Readiness probe failure threshold.

Resources and Security

Parameter	Type	Default	Description
`resources`	object	`{}`	CPU and memory requests and limits.
`podSecurityContext`	object	`{}`	Pod-level security context.
`securityContext`	object	`{}`	Container-level security context.

Service Account

Parameter	Type	Default	Description
`serviceAccount.create`	boolean	`false`	Create a dedicated ServiceAccount.
`serviceAccount.name`	string	`""`	Override the ServiceAccount name.
`serviceAccount.annotations`	object	`{}`	Annotations for the ServiceAccount.

Scheduling

Parameter	Type	Default	Description
`nodeSelector`	object	`{}`	Node selector for scheduling.
`tolerations`	array	`[]`	Tolerations for scheduling.
`affinity`	object	`{}`	Affinity rules.
`topologySpreadConstraints`	array	`[]`	Topology spread constraints.
`priorityClassName`	string	`""`	PriorityClass for the pod.
`terminationGracePeriodSeconds`	integer	`30`	Termination grace period.
`podLabels`	object	`{}`	Extra labels for the pod.
`podAnnotations`	object	`{}`	Extra annotations for the pod.

Extra

Parameter	Type	Default	Description
`extraVolumes`	array	`[]`	Extra volumes to attach to the pod.
`extraVolumeMounts`	array	`[]`	Extra volume mounts for the container.
`extraManifests`	array	`[]`	Extra Kubernetes manifests deployed alongside the chart.

Common Issues

Jobs not running after pod restart

If scheduled jobs stop running after a pod restart, verify that persistence.enabled: true and that the PVC is correctly mounted. Cronicle stores all job definitions in the PVC — if it is not mounted, the scheduler starts with no configured jobs.

Viewing job output and history

Cronicle stores job run logs in the web UI under Activity Log. For debugging, live output is visible in real time during job execution. Historical log files are also stored in the PVC under /opt/cronicle/data/logs/.