Functions

What it is

A function is a unit of deployed backend logic (JavaScript/TypeScript, Python, or Ruby) that Volcano builds, packages, and runs on a managed runtime. It is invoked over HTTP, by name/alias, or on a schedule.

How it relates

• Belongs to a project.
• Reads configuration and secrets from variables. By default it receives every project variable; declare a narrower variable scope to give it only the ones it needs.
• Connects to databases and storage in the same project.
• Its visibility (public/private) and schedulers can be declared in the declarative config or managed with the CLI.
• Can be given an alias so you can invoke it by a friendly name.
• Work that has to run for hours belongs in a durable function instead, which is a separate collection with its own commands.

The CLI discovers functions in the volcano/functions directory, detects the runtime from source file extensions, and uploads a packaged archive.

If a volcano-config.yaml is present, functions deploy also sends the variable_scope and variables declared there for each function it uploads. Functions the manifest does not mention keep their existing scope. The manifest is only read — deploying never writes it back. See variable scope.

Because those declarations come from the manifest, a manifest that is present but cannot be read stops the deploy before anything is uploaded, and the error says what to fix. That includes a ${VAR} reference anywhere in the file whose environment variable is not set in the deploying shell, even in a section unrelated to functions. Deploying past it would upload a function without the scope it declared, giving it every project variable. With no volcano-config.yaml at all there is nothing to declare and deploy runs normally.

CLI operations

Prefix with cloud (e.g. volcano cloud functions deploy) to target cloud. Without the prefix, function commands always target local development.

Cloud deploys use latest-wins queueing. If the function is already deploying, the new source replaces any older queued deploy and runs next. Delete supersedes queued deploys; later deploys are rejected until deletion finishes.

Examples

# Deploy everything, or a single function by name or path
volcano functions deploy --all
volcano functions deploy -f get-notes
volcano functions deploy -f volcano/functions/get-notes.js

# Invoke with a JSON payload; --json prints compact machine output
volcano functions invoke hello --payload '{"name":"Ada"}'
volcano functions invoke hello --json
volcano functions invoke --id 33333333-3333-4333-8333-333333333333

# Tail build/runtime logs
volcano functions logs hello

# Schedule a function (cron), then disable it
volcano functions schedulers create hello --name refresh-cache --cron "*/5 * * * *"
volcano functions schedulers disable hello --name refresh-cache

# Invoke-by-alias
volcano functions alias set hello 44444444-4444-4444-8444-444444444444
volcano functions invoke hello