feat: publish standalone worker

Separate worker packaging and service lifecycle from the control plane.

internal/workercluster/entries.go

@@ -0,0 +1,152 @@
+package workercluster
+
+import "encoding/json"
+
+// EntryType enumerates the kinds of replicated log entries the FSM
+// understands. Every log entry committed through the Raft Apply path
+// carries an Entry of one of these kinds.
+//
+// The set is the subset from plan section 6.2 that this implementation
+// actually exercises today. The remaining kinds are defined in
+// distworker/entries.go placeholders (ObserverSetUpdate, IncidentObserve,
+// ...) so later phases can add Apply branches without a wire-format
+// churn.
+type EntryType string
+
+const (
+	// EntryConfigAdopt installs a new adopted critical-check list
+	// into the FSM. Replaces any previously adopted list.
+	EntryConfigAdopt EntryType = "config.adopt"
+
+	// EntryObserverSetUpdate installs a new observer set with a
+	// version stamp.
+	EntryObserverSetUpdate EntryType = "observer_set.update"
+
+	// EntryMembershipProposeAdd appends a Member to the membership
+	// cache. The Raft library itself handles the voter promotion; the
+	// FSM just keeps a denormalized mirror.
+	EntryMembershipProposeAdd EntryType = "membership.propose_add"
+
+	// EntryMembershipDemote flips a voter's role to observer.
+	EntryMembershipDemote EntryType = "membership.demote"
+
+	// EntryMembershipRemove drops a Member from the membership cache.
+	EntryMembershipRemove EntryType = "membership.remove"
+
+	// EntryIncidentObserve appends one observer vote for a check.
+	EntryIncidentObserve EntryType = "incident.observe"
+
+	// EntryIncidentTransition records a state transition produced by
+	// the FSM from committed observations.
+	EntryIncidentTransition EntryType = "incident.transition"
+
+	// EntryOutboxEnqueue appends notification outbox metadata.
+	EntryOutboxEnqueue EntryType = "outbox.enqueue"
+
+	// EntryOutboxDelivered marks an outbox entry as delivered.
+	EntryOutboxDelivered EntryType = "outbox.delivered"
+
+	// EntryOutboxAck records a delivery ack / duplicate marker.
+	EntryOutboxAck EntryType = "outbox.ack"
+
+	// EntryPartitionReport stores the cluster's view of network
+	// partition state.
+	EntryPartitionReport EntryType = "partition.report"
+
+	// EntryDiagnosticsUpdate stores per-worker health metadata.
+	EntryDiagnosticsUpdate EntryType = "diagnostics.update"
+)
+
+// Entry is the wire format the FSM expects on every Apply. The Data
+// field holds the JSON-encoded payload of the matching struct.
+type Entry struct {
+	Type     EntryType       `json:"type"`
+	Term     uint64          `json:"term,omitempty"`
+	Index    uint64          `json:"index,omitempty"`
+	ActorID  string          `json:"actor_id,omitempty"`
+	Version  uint64          `json:"version,omitempty"`
+	Adopted  json.RawMessage `json:"adopted,omitempty"`
+	Set      json.RawMessage `json:"set,omitempty"`
+	Member   json.RawMessage `json:"member,omitempty"`
+	State    json.RawMessage `json:"state,omitempty"`
+	Observe  json.RawMessage `json:"observe,omitempty"`
+	Outbox   json.RawMessage `json:"outbox,omitempty"`
+	OutboxID uint64          `json:"outbox_seq,omitempty"`
+	Report   json.RawMessage `json:"report,omitempty"`
+	Diag     json.RawMessage `json:"diag,omitempty"`
+}
+
+// ConfigAdoptPayload is the body of an EntryConfigAdopt entry.
+type ConfigAdoptPayload struct {
+	Version uint64                `json:"version"`
+	Actor   string                `json:"actor"`
+	Checks  []CriticalCheckConfig `json:"checks"`
+}
+
+// ObserverSetPayload is the body of an EntryObserverSetUpdate entry.
+type ObserverSetPayload struct {
+	Set ObserverSet `json:"set"`
+}
+
+// MemberPayload is the body of an EntryMembershipProposeAdd,
+// EntryMembershipDemote, and EntryMembershipRemove entries.
+type MemberPayload struct {
+	Member Member  `json:"member"`
+	Reason string  `json:"reason,omitempty"`
+	Prev   *Member `json:"prev,omitempty"` // populated on demote/remove
+}
+
+// IncidentObservePayload is one observer vote for a check.
+type IncidentObservePayload struct {
+	CheckID    int64  `json:"check_id"`
+	WorkerID   string `json:"worker_id"`
+	Label      string `json:"label"` // ok | warn | down | unknown
+	ObservedIx uint64 `json:"observed_at_index"`
+}
+
+// IncidentTransitionPayload is the FSM-produced state transition
+// recorded after a quorum rule fires.
+type IncidentTransitionPayload struct {
+	CheckID int64         `json:"check_id"`
+	State   IncidentState `json:"state"`
+	Reason  string        `json:"reason,omitempty"`
+}
+
+// OutboxPayload is the body of an EntryOutboxEnqueue entry.
+type OutboxPayload struct {
+	Entry OutboxMeta `json:"entry"`
+}
+
+// OutboxUpdatePayload is the body of EntryOutboxDelivered and
+// EntryOutboxAck entries.
+type OutboxUpdatePayload struct {
+	Seq       uint64 `json:"seq"`
+	State     string `json:"state"`
+	Attempts  int    `json:"attempts"`
+	LastError string `json:"last_error,omitempty"`
+}
+
+// PartitionReportPayload is the body of an EntryPartitionReport entry.
+type PartitionReportPayload struct {
+	State PartitionState `json:"state"`
+}
+
+// DiagnosticsPayload is the body of an EntryDiagnosticsUpdate entry.
+type DiagnosticsPayload struct {
+	Diag WorkerDiagnostics `json:"diag"`
+}
+
+// EncodeEntry marshals a fully-populated Entry to JSON bytes ready to
+// hand to raft.Apply.
+func EncodeEntry(e *Entry) ([]byte, error) {
+	return json.Marshal(e)
+}
+
+// DecodeEntry parses Entry bytes back into the wire struct.
+func DecodeEntry(b []byte) (Entry, error) {
+	var e Entry
+	if err := json.Unmarshal(b, &e); err != nil {
+		return e, err
+	}
+	return e, nil
+}