Create Environment
Create a language runtime environment with fission env create, set CPU/memory limits and poolsize, and attach a builder image for source builds.
Function
Fission function
Create Function
Create a function with fission fn create, route HTTP traffic to it, test it, and update its code through the everyday function workflow.
Accessing URL parameters
Define path parameters in an HTTP trigger URL with gorilla/mux patterns and read their values inside a function via request headers.
Accessing Secrets/ConfigMaps
Mount Kubernetes Secrets and ConfigMaps into a Fission function and read their values for API keys and configuration.
Pull an Image From a Private Registry
Pull environment images from a private registry by passing an imagePullSecret to fission environment create with –imagepullsecret.
Use URL as archive source when creating functions/packages
Embed a remote URL directly in a package archive when creating functions or packages to cut creation time and improve spec portability.
Packaging source code
Create source and deployment packages with fission package, build source archives on the cluster with a builder, and attach packages to functions.
OCI image packages
Ship Fission function code as an OCI image instead of an archive: build a code-only image, create a package with –oci, and pin digests for fast cold starts.
Building a Custom Environment
Build or modify a Fission environment: implement the specialize HTTP contract, write the runtime and builder images, test locally, and add a new language.
Controlling Function Execution
Choose and configure a function executor (poolmgr, newdeploy, or container) with –executortype to control cold starts and per-function autoscaling.
Running container as functions
Run an existing container image as a function with the container executor via fission function run-container, without an environment or builder.
Streaming Responses
Stream a Fission function’s response incrementally over Server-Sent Events, HTTP chunked transfer, or WebSocket — for LLM tokens, chat, and long-running calls.
Canary Deployments for Functions
Gradually shift HTTP traffic to a new function version with a CanaryConfig, using Prometheus health checks to auto-rollback on failure.
Functions as MCP Tools
Expose a Fission function as a Model Context Protocol (MCP) tool so LLM agents can discover and invoke it, with a JSON Schema for inputs and JWT-scoped access.
Enabling Istio on Fission
Install Fission with the Istio service mesh and enable automatic sidecar injection for Fission and function pods.