Struct ServerSettings 

pub struct ServerSettings {
    pub agent_prune_days: Option<u32>,
}

Value stored in the server_settings KV bucket under the single key crate::kv::KEY_SERVER_SETTINGS. Operator-editable, backend-side server configuration that isn’t per-agent (so it doesn’t belong in agent_config’s layered scopes) and isn’t a fleet-wide switch every agent watches (so it doesn’t belong in fleet_config). Managed via the SPA Settings page’s “server settings” tab.

Every field is Option<_>: None (the default / the JSON value null / the field simply absent) means unset — fall back to the built-in default (ServerSettings::defaults), exactly like the agent layered-config scopes. The SPA renders the built-in default as a faint placeholder so a blank field shows what it resolves to, and when a real default is introduced here it appears in the UI (and takes effect for already-deployed-but-unset fleets) for free.

#[serde(default)] on the container keeps the document backward/forward compatible: a freshly-created or missing key decodes to all-None (pre-feature behaviour), an older backend reading a newer document ignores unknown fields, and a newer backend reading an older document fills the missing field with None. Keep that invariant — never add a field whose None doesn’t mean “behave as before”.

Fields

agent_prune_days: Option<u32>

Days a dead agent (one whose heartbeat stopped arriving) may linger in the agents registry before the backend cleanup task prunes its row.

None (unset) falls back to the built-in default; with no default configured that resolves to pruning disabled (see ServerSettings::effective_agent_prune_days). A positive value makes the cleanup sweep delete rows whose last_heartbeat is older than that many days. The agents table is a projection of the heartbeat stream, so a machine that’s merely offline (not gone) reappears on its next heartbeat (~30s cadence); only genuinely-retired machines stay gone.

Implementations

impl ServerSettings

pub fn defaults() -> Self

Built-in defaults applied when a field is unset (None) in the stored document. Currently every field is None: there’s no fleet-meaningful default prune window, so leaving it blank means “disabled” rather than some arbitrary number of days.

Exposed via GET /api/server-settings/defaults so the SPA renders these as faint placeholders (mirroring the agent layered-config page’s built-in floor). Introducing a real default later is a one-line change here that automatically shows up in the UI and applies to every deployment that hasn’t overridden the field.

pub fn effective_agent_prune_days(&self) -> u32

The effective dead-agent prune window in days: the stored value if set, else the built-in default, else 0 (= pruning disabled). The final unwrap_or(0) is the absent-everywhere floor, not a user-facing default — the cleanup task treats 0 as “don’t prune”.

Clamped to MAX_AGENT_PRUNE_DAYS so the cleanup task’s now - Duration::days(n) can never overflow DateTime (and panic the task), even if a value larger than the PUT handler allows was written to the KV out-of-band.

Trait Implementations

impl Clone for ServerSettings

fn clone(&self) -> ServerSettings

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ServerSettings

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

Formats the value using the given formatter.

impl Default for ServerSettings

fn default() -> ServerSettings

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ServerSettings

where ServerSettings: Default,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ServerSettings

impl PartialEq for ServerSettings

fn eq(&self, other: &ServerSettings) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for ServerSettings

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ServerSettings