Add config for downloading repo migrations

Author: gammazero

config.go

@@ -29,6 +29,7 @@ type Config struct {
 	Pubsub    PubsubConfig
 	Peering   Peering
 	DNS       DNS
+	Migration Migration
 
 	Provider     Provider
 	Reprovider   Reprovider

init.go

@@ -92,6 +92,10 @@ func InitWithIdentity(identity Identity) (*Config, error) {
 		DNS: DNS{
 			Resolvers: map[string]string{},
 		},
+		Migration: Migration{
+			DownloadSources: DefaultMigrationDownloadSources,
+			Keep:            DefaultMigrationKeep,
+		},
 	}
 
 	return conf, nil

migration.go

@@ -0,0 +1,22 @@
+package config
+
+import "github.com/libp2p/go-libp2p-core/peer"
+
+const DefaultMigrationKeep = "cache"
+
+var DefaultMigrationDownloadSources = []string{"HTTPS", "IPFS"}
+
+// Migration configures how migrations are downloaded and if the downloads are
+// added to IPFS locally
+type Migration struct {
+	// Sources in order of preference where "HTTPS" means our gateways and
+	// "IPFS" means over IPFS. Any other values are interpretes as hostnames
+	// for custom gateways. An empty list means "do the default thing"
+	DownloadSources []string
+	// Whether or not to keep the migration after downloading it.
+	// Options are "discard", "cache", "pin".  Empty string for default.
+	Keep string
+	// Peers lists the nodes to attempt to connect with when downloading
+	// migrations.
+	Peers []peer.AddrInfo
+}