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.

---

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.

---

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

graph TD
  T["Trigger (HTTP, Event, Schedule)"] --> F["OCI Functions: Container (Your Code)"]
  F --> R["Response / Output"]

---

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.

---

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

---

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:

graph LR
  G1["GET /api/users"] --> GW1["OCI API Gateway"]
  GW1 --> Fn1["OCI Function (get-users)"]
  P1["POST /api/orders"] --> GW2["OCI API Gateway"]
  GW2 --> Fn2["OCI Function (create-order)"]

Event Triggers (Events Service)

Trigger functions in response to OCI events: