OCI Functions and Serverless

OCI Functions is a serverless compute platform that lets you run code without managing infrastructure. Built on the open-source Fn Project, OCI Functions provides a standards-based, event-driven compute service.

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What is OCI Functions?

OCI Functions lets you:

• Write small, focused pieces of code (functions)
• Deploy them without provisioning servers
• Pay only for the time your code executes
• Scale automatically from zero to thousands of concurrent executions

OCI Functions is based on the Fn Project, an open-source, container-native serverless platform.

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How OCI Functions Works

1. You write a function in a supported language
2. The function is packaged as a Docker container
3. You deploy it to an application (a logical grouping of functions)
4. When invoked, OCI provisions the container, runs your code, and returns the result

Trigger (HTTP, Event, Schedule)
        │
        ▼
┌─────────────────┐
│  OCI Functions   │
│  ┌─────────────┐ │
│  │ Container   │ │
│  │ (Your Code) │ │
│  └─────────────┘ │
└────────┬────────┘
         │
         ▼
    Response / Output

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Supported Runtimes

Runtime	Versions
Java	8, 11, 17
Python	3.8, 3.9, 3.11
Node.js	14, 18
Go	1.19+
Ruby	2.7
C#	.NET 6
Custom	Any language via a Docker image

Since functions are packaged as containers, you can use any language with a custom Docker image.

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Applications and Functions

Applications

An application is a logical grouping of functions:

• Shares a VCN subnet (for network access)
• Shares configuration (environment variables, logging)
• Applied IAM policies at the application level

Functions

A function is a single unit of code within an application:

• Has its own Docker image
• Has configurable memory (128 MB to 1,024 MB) and timeout (up to 300 seconds)
• Scales independently

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Invoking Functions

Direct Invocation

Call a function using the OCI CLI or SDK:

oci fn function invoke --function-id <ocid> --body '{"name": "world"}'

HTTP Triggers (API Gateway)

Expose functions as HTTP endpoints using OCI API Gateway:

GET /api/users → OCI API Gateway → OCI Function (get-users)
POST /api/orders → OCI API Gateway → OCI Function (create-order)

Event Triggers (Events Service)

Trigger functions in response to OCI events: