Struct ChildLaunchRequest 

pub struct ChildLaunchRequest {
    pub parent_accessible_root: WorkdirRoot,
    pub capsule_name: String,
    pub capsule_version: String,
    pub grant: SpawnApproval,
    pub child_env_allow: Vec<String>,
    pub roost_url: String,
    pub spawner: Option<Spawner>,
    pub completion_deadline: Option<Duration>,
    pub formation_id: Option<FormationId>,
}

What the parent’s runtime needs in order to start one approved child.

Carries no manifest and no capability declaration: what the child holds is decided by the daemon from the child’s own registry manifest, both at the POST /spawn that granted grant and again at the POST /register the child performs for itself.

Fields

parent_accessible_root: WorkdirRoot

The parent’s own accessible workdir. The child’s directory is created beneath it, with no link followed, which is what keeps the child inside the single preopen the parent’s WASI layer already has.

capsule_name: String

capsule_version: String

grant: SpawnApproval

The approval POST /spawn returned, spent by the child’s own registration.

child_env_allow: Vec<String>

The child’s capabilities.env.allow. Names listed here are copied from the parent’s process environment into the child’s; every other host variable the parent holds is absent from the child, because the child’s environment is built from a cleared one.

roost_url: String

Base URL of the daemon the child registers with.

spawner: Option<Spawner>

The session this child belongs to, or None for a launch that is not a delegation.

Some is what turns the launch into a delegation: the launcher mints a delegation id and injects a SpawnerHandle as SPAWNER_ENV, which is where the child reads the lineage it records in its own session_start. The watcher that reports for a child which could not report for itself starts only when that spawner also names a CompletionAddress — a parent waiting on its own connection wants no completion. None injects nothing and starts nothing.

completion_deadline: Option<Duration>

How long the completion watcher observes this child before ending it, or None to observe it for as long as it runs.

Meaningful only alongside a CompletionAddress, because the watcher that enforces it starts only for a spawner that names one. On expiry the watcher stops the process and posts a DelegationStatus::Terminated outcome naming the bound, which is the only thing that tells a parent about a child that never ends.

formation_id: Option<FormationId>

The parent session’s formation, which the child joins: injected as FORMATION_ID_ENV when Some, whether or not Self::spawner is. Inherited from the parent and never minted here; None — a parent in no formation — injects nothing.

Trait Implementations

impl Debug for ChildLaunchRequest

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.