Fan-out

The for block lives inside a job or service and wraps env and run. It iterates over a typed iterable, binding a local variable per iteration — one process instance is spawned for each element.

Basic Example

job nodes {
  for config_path in glob("configs/node-*.yaml") {
    env NODE_CONFIG = config_path
    run "start-node --config $NODE_CONFIG"
  }
}

This spawns one instance per matching file, each with its own NODE_CONFIG environment variable.

Iterable Types

Syntax	Description
`glob("pattern")`	File glob, evaluated at runtime (after `wait` conditions are satisfied), sorted lexicographically. Zero matches is a runtime error.
`["a", "b", "c"]`	Literal array of strings
`0..3`	Exclusive range: 0, 1, 2
`0..=3`	Inclusive range: 0, 1, 2, 3

`glob()`

job nodes {
  for config_path in glob("configs/node-*.yaml") {
    env NODE_CONFIG = config_path
    run "start-node --config $NODE_CONFIG"
  }
}

Literal array

job services {
  for svc in ["auth", "billing", "notifications"] {
    env SERVICE = svc
    run "deploy-service $SERVICE"
  }
}

Range

service workers {
  for i in 0..4 {
    env WORKER_ID = i
    run "worker --id $WORKER_ID"
  }
}

Instance Naming

Instances are named {job_name}-{index} where the index is 0-based. For the nodes example with three glob matches, the instances are nodes-0, nodes-1, and nodes-2.

An after @nodes condition in another job’s wait block is satisfied only when all instances have exited successfully (exit code 0). This lets you gate a downstream job on the entire fan-out group completing:

job nodes {
  for config_path in glob("configs/node-*.yaml") {
    env NODE_CONFIG = config_path
    run "provision --config $NODE_CONFIG"
  }
}

job deploy {
  wait {
    after @nodes
  }

  run "deploy-cluster"
}

Here deploy will not start until every nodes-* instance has completed successfully.

Env Inheritance

env bindings outside the for block apply to all instances. Bindings inside are per-iteration:

job nodes {
  env CLUSTER = "prod"

  for config_path in glob("configs/*.yaml") {
    env NODE_CONFIG = config_path
    run "start-node --config $NODE_CONFIG --cluster $CLUSTER"
  }
}

All instances share CLUSTER=prod, but each gets its own NODE_CONFIG.

Scoping

The iteration variable is scoped to the for block
It shares the local variable namespace with var bindings from contains conditions
args.x and @job.KEY have distinct syntactic prefixes and cannot collide with bare local names
Shadowing any existing local variable name is a parse-time error

procman