FastAPI Helm Chart

This repository contains a Helm chart for a FastAPI application to be deployed on OpenShift clusters with minimal effort with customizable configurations.

Prerequisites

• Helm CLI (version 3+)
• OpenShift Cluster (version 4.x recommended)
• Docker (for building application images)
• Poetry (for Python dependency management)

Configuration

The following tables describe the configurable parameters of the FastAPI Helm chart. You can override these values by creating your own values.yaml file.

Core Configuration

Parameter	Description	Default
replicaCount	Number of replicas of the FastAPI application	1

Image Configuration

Parameter	Description	Default
image.registry	Docker registry for the FastAPI image	""
image.repository	Docker image repository	""
image.tag	Docker image tag	""
image.pullPolicy	Image pull policy (Always, IfNotPresent, Never)	IfNotPresent
imagePullSecrets	Image pull secrets for private registries	[]

Network Configuration

Parameter	Description	Default
service.type	Kubernetes service type (ClusterIP, LoadBalancer, NodePort)	ClusterIP
service.port	Service port for accessing the application	80

Environment Variables (ConfigMap)

You can define as many environment variables as needed in the configMap. The chart comes with some default FastAPI application environment variables. These variables will be available to your FastAPI application at runtime.

Parameter	Description	Default
configMap.data.APP_NAME	Name of the FastAPI application	"Example FastAPI App"
configMap.data.DEBUG	Enable debug mode (true/false)	false
configMap.data.VERSION	Application version	"0.1.0"

To add or modify environment variables, you can update the configMap.data section in your values.yaml file. For example:

configMap:
  data:
    APP_NAME: "My FastAPI Application"
    DEBUG: "false"
    VERSION: "1.0.0"
    CUSTOM_VAR: "custom-value"  # Add your custom variables here

OpenShift Route Configuration

Parameter	Description	Default
route.enabled	Enable OpenShift route for external access	false
route.host	Route hostname (e.g., myapp.apps.cluster.com)	""
route.path	Route path	/
route.tls.enabled	Enable TLS for secure routes	false
route.tls.termination	TLS termination type (edge, passthrough, reencrypt)	edge
route.tls.insecureEdgeTerminationPolicy	How to handle insecure traffic	Allow

Resource Management

Parameter	Description	Default
resources.limits.cpu	Maximum CPU allocation	""
resources.limits.memory	Maximum memory allocation	""
resources.requests.cpu	Minimum CPU requirement	""
resources.requests.memory	Minimum memory requirement	""

Scheduling Configuration

Parameter	Description	Default
nodeSelector	Node labels for pod assignment	{}
tolerations	Pod tolerations for node taints	[]
affinity	Pod affinity/anti-affinity rules	{}

Build the Docker image

Build

docker build -t {YOUR_DOCKER_REGISTRY}/{YOUR_DOCKER_IMAGE_NAME}:{YOUR_DOCKER_TAG} .

Tag

docker tag {YOUR_DOCKER_IMAGE_NAME}:{YOUR_DOCKER_TAG} {YOUR_DOCKER_REGISTRY}/{YOUR_DOCKER_IMAGE_NAME}:{YOUR_DOCKER_TAG}

Push

docker push {YOUR_DOCKER_REGISTRY}/{YOUR_DOCKER_IMAGE_NAME}:{YOUR_DOCKER_TAG}

Example of Implemented Values.yaml file

# Number of application replicas to run
replicaCount: 1

# Container image configuration
image:
  repository: {YOUR_DOCKER_REGISTRY}  # e.g., quay.io/myorg/myapp
  tag: {YOUR_DOCKER_TAG}  # e.g., latest, v1.0.0
  pullPolicy: {YOUR_DOCKER_PULL_POLICY}  # Usually IfNotPresent or Always

# Secrets for pulling images from private registries
imagePullSecrets:
  - name: {YOUR_IMAGE_PULL_SECRET_NAME}

# Optional name overrides
nameOverride: ""
fullnameOverride: ""

# Service configuration for accessing your application
service:
  type: LoadBalancer  # Can be ClusterIP, LoadBalancer, or NodePort
  port: 80  # Port your service will listen on

# Environment variables for your application
configMap:
  data:
    APP_NAME: {YOUR_APP_NAME}  # e.g., "My FastAPI App"
    DEBUG: {YOUR_DEBUG_VALUE}  # e.g., "false"
    VERSION: {YOUR_VERSION}  # e.g., "1.0.0"
    # Add your custom environment variables here

# Resource limits and requests
resources:
  limits:
    cpu: 100m  # 100 millicores = 0.1 CPU
    memory: 128Mi  # 128 megabytes
  requests:
    cpu: 100m
    memory: 128Mi

# Pod scheduling configurations
nodeSelector: {}  # Add node selectors if needed

tolerations: []  # Add tolerations if needed

affinity: {}  # Add affinity rules if needed

Add the repository to your Helm CLI

helm repo add fastapi-helm-chart https://anqorithm.github.io/fastapi-helm-chart/charts/fastapi

Install the chart

helm install my-fastapi-helm-chart fastapi-helm-chart/fastapi-helm-chart --version 0.0.4

Installation

To install the chart with the release name "fastapi-chart":

Clone the repository

git clone https://github.com/anqorithm/fastapi-helm-chart.git

Install the chart

helm install fastapi-chart ./charts/fastapi

Open OpenShift to see the application

Create a route to access the application

Access the application

This will deploy your FastAPI application to the OpenShift cluster using the default configuration values. For custom configurations, create a values.yaml file with your desired settings and use:

helm install fastapi-chart ./charts/fastapi -f values.yaml

Contributing

Contributions are welcome! Please feel free to submit a PR.

Contributors

• Abdullah Alqahtani

License

This project is licensed under the MIT License. See the LICENSE file for details.

Acknowledgments

• FastAPI
• OpenShift
• Kubernetes
• Helm
• Artifact Hub
• Poetry
• Docker
• GitHub
• Bitbucket