open-design/charts/open-design

Introduction

This chart bootstraps an Open Design deployment on a Kubernetes cluster using the Helm package manager.

Prerequisites

• Kubernetes 1.23+
• Helm 3.8.0+
• PV provisioner support in the underlying infrastructure (if persistence is enabled)

Installing the Chart

To install the chart with the release name my-release:

helm install my-release ./charts/open-design

These commands deploy an Open Design application on the Kubernetes cluster in the default configuration.

Tip: List all releases using helm list

Architecture and Configuration Notes

SQLite State & Concurrency Limitations

The current Open Design runtime stores state in local files and SQLite under /app/.od. Because SQLite does not support concurrent writes from multiple network replicas, this chart is strictly limited to 1 replica.

Horizontal Pod Autoscaling (HPA) is disabled by default. Do not enable HPA or scale the deployment beyond replicas: 1 unless you have modified the application to externalize the state to a standalone database.

Server-Sent Events (SSE) and Ingress

Open Design relies on Server-Sent Events (SSE) for real-time streaming. If you enable the Ingress resource, it is critical to disable reverse-proxy buffering. If you are using the NGINX Ingress Controller, this chart automatically applies the required annotations by default:

nginx.ingress.kubernetes.io/proxy-buffering: "off"
nginx.ingress.kubernetes.io/proxy-read-timeout: "600"
nginx.ingress.kubernetes.io/proxy-send-timeout: "600"

Path Constraints: Non-root ingress path prefixes (sub-paths) are explicitly unsupported by the proxy routing stack. Ingress paths must be configured as /.

Authentication Proxy

An authentication proxy (NGINX) is introduced to front the application. This proxy runs as a mandatory sidecar container alongside the main application. The Kubernetes Service routes traffic to the proxy, which handles authentication for the API and health checks, proxying valid requests to the application.

Security Context

This chart adheres to strict security defaults:

• Runs as non-root user 1001.
• Drops all kernel capabilities (ALL).
• Enforces a readOnlyRootFilesystem.
• Prevents privilege escalation.

Parameters

Global & Image Parameters

Name	Description	Value
commonLabels	Custom labels injected into all resources	{app.kubernetes.io/environment: production}
image.repository	Open Design image repository	vanjayak/open-design
image.pullPolicy	Image pull policy	IfNotPresent
image.tag	Image tag (overrides AppVersion)	latest

Application Configuration

Name	Description	Value
config.nodeEnv	Node.js environment (production or development)	production
config.allowedOrigins	CORS allowed origins. Mandatory if service.type is LoadBalancer or NodePort to prevent 403 render failures.	""
config.publicBaseUrl	Public base URL used by the application (derived dynamically if empty)	""
config.nodeOptions	V8 engine memory optimizations	--max-old-space-size=192
config.webPort	Web server listening port	7456
config.bindHost	Host to bind the web server to	"127.0.0.1"
config.apiToken	API authentication token (must be changed from default)	"secure-default-token-change-me"

Auth Proxy Parameters

Name	Description	Value
authProxy.image	NGINX proxy image	nginxinc/nginx-unprivileged:1.25-alpine-slim
authProxy.port	Proxy server port inside the container	8080
authProxy.securityContext	Security context for the proxy container	{...}

Health Check Parameters

Name	Description	Value
livenessProbe.enabled	Enable liveness probe	true
livenessProbe.initialDelaySeconds	Initial delay seconds for liveness probe	20
livenessProbe.periodSeconds	Period seconds for liveness probe	30
livenessProbe.timeoutSeconds	Timeout seconds for liveness probe	5
livenessProbe.failureThreshold	Failure threshold for liveness probe	3
readinessProbe.enabled	Enable readiness probe	true
readinessProbe.initialDelaySeconds	Initial delay seconds for readiness probe	5
readinessProbe.periodSeconds	Period seconds for readiness probe	10
readinessProbe.timeoutSeconds	Timeout seconds for readiness probe	5
readinessProbe.failureThreshold	Failure threshold for readiness probe	3

Network & Ingress Parameters

Name	Description	Value
service.type	Kubernetes Service type	ClusterIP
service.port	Service HTTP port	80
ingress.enabled	Enable ingress record generation	false
ingress.className	Ingress class name	nginx
ingress.annotations	Additional custom annotations for Ingress (e.g., SSE fixes)	{...}
ingress.hosts[0].host	Hostname for the ingress record	open-design.local
ingress.tls	TLS configuration for ingress records	[]

Persistence Parameters

Name	Description	Value
persistence.enabled	Enable PVC for SQLite and file state	true
persistence.storageClass	Storage class (leave empty to use cluster default)	""
persistence.accessMode	PVC Access Mode	ReadWriteOnce
persistence.size	PVC Storage Request	10Gi

Resources & Autoscaling Parameters

Name	Description	Value
replicaCount	Number of application replicas	1
resources.limits.cpu	CPU limits for the container	1000m
resources.limits.memory	Memory limits for the container	1024Mi
resources.requests.cpu	CPU requests for the container	200m
resources.requests.memory	Memory requests for the container	256Mi
hpa.enabled	Enable Horizontal Pod Autoscaler (WARNING: Breaks SQLite)	false

Security & Scheduling Parameters

Name	Description	Value
podSecurityContext.fsGroupChangePolicy	Set filesystem group change policy	Always
podSecurityContext.sysctls	Set kernel settings using the sysctl interface	[]
podSecurityContext.supplementalGroups	Set filesystem extra groups	[]
podSecurityContext.fsGroup	Group ID for the persistent volume	1001
containerSecurityContext.seLinuxOptions	Set SELinux options in container	{}
containerSecurityContext.runAsUser	Run the application as this UID	1001
containerSecurityContext.runAsGroup	Run the application as this GID	1001
containerSecurityContext.runAsNonRoot	Set container's Security Context runAsNonRoot	true
containerSecurityContext.privileged	Set container's Security Context privileged	false
containerSecurityContext.readOnlyRootFilesystem	Enforce read-only root FS	true
containerSecurityContext.allowPrivilegeEscalation	Set container's Security Context allowPrivilegeEscalation	false
containerSecurityContext.capabilities.drop	List of capabilities to be dropped	["ALL"]
containerSecurityContext.seccompProfile.type	Set container's Security Context seccomp profile	"RuntimeDefault"
nodeSelector	Node labels for pod assignment	{}
tolerations	Tolerations for pod assignment	[]
affinity	Affinity rules for pod assignment	{}
initContainers	Additional init containers to add to the pod	[]
sidecars	Additional sidecar containers to add to the pod	[]

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

helm install my-release --set config.nodeEnv=development ./charts/open-design

The above command sets the Open Design node environment to development.

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

helm install my-release -f values.yaml ./charts/open-design

Tip: You can use the default values.yaml