now we talkin, updates to db now get reflected in cluster!

src/state/db.go

@@ -0,0 +1,89 @@
+package state
+
+import (
+	"context"
+
+	log "bitsnthings.dev/overlord/src/log"
+	"libvirt.org/go/libvirt"
+
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+func (state *State) setDBWatchers() {
+	state.startWatchStreamHandler(
+		*state.MongoDB.Collection("domains"),
+		mongo.Pipeline{},
+		state.Libvirt.DomainChangeHandler)
+}
+
+func (state *State) startWatchStreamHandler(
+	collection mongo.Collection,
+	pipeline mongo.Pipeline,
+	handler func(*mongo.ChangeStream),
+) {
+	stream, err := collection.Watch(
+		context.TODO(),
+		pipeline,
+		state.streamOpts)
+	if err != nil {
+		log.PrintLog(
+			log.ERROR,
+			"Error starting mongodb watch stream! %s",
+			err)
+		stream.Close(context.TODO())
+		return
+	}
+	state.changeStreams = append(state.changeStreams, stream)
+	go handler(stream)
+}
+
+func (state *State) fetchDBState() {
+
+}
+
+func (state *State) pushDBState() {
+	for uri, domMap := range state.Libvirt.Domains.Active {
+		setDomainStatesInDB(
+			domMap, state, true, uri, state.upsertOpts)
+	}
+	for uri, domMap := range state.Libvirt.Domains.Inactive {
+		setDomainStatesInDB(
+			domMap, state, false, uri, state.upsertOpts)
+	}
+}
+
+func setDomainStatesInDB(
+	domMap map[string]libvirt.Domain,
+	state *State,
+	domainState bool,
+	uri string,
+	opts *options.UpdateOptions,
+) {
+	var flags libvirt.DomainXMLFlags
+	if !state.Libvirt.IsReadOnly(uri) {
+		flags = libvirt.DOMAIN_XML_INACTIVE + libvirt.DOMAIN_XML_INACTIVE
+	}
+	for uuid, dom := range domMap {
+		xml, err := dom.GetXMLDesc(flags)
+		if err != nil {
+			log.PrintLog(
+				log.ERROR,
+				"Error getting XML of domain with uuid: \"%s\" on node with uri: \"%s\"! %s",
+				uuid, uri, err)
+		}
+		state.MongoDB.Collection("domains").UpdateOne(
+			context.TODO(),
+			bson.D{
+				{Key: "uri", Value: uri},
+				{Key: "uuid", Value: uuid}},
+			bson.D{
+				{Key: "$set", Value: bson.M{
+					"active": domainState,
+					"xml":    xml,
+				}}},
+			opts,
+		)
+	}
+}