From d2bf1bc7b646b85b3480cb0e0828b6e979093a23 Mon Sep 17 00:00:00 2001
From: Hector Sanjuan <code@hector.link>
Date: Mon, 2 Dec 2019 12:52:24 +0100
Subject: [PATCH] config: Add PeerAddresses

This adds a PeerAddresses entry to the main cluster configuration.

The peer will ingest and potentially connect to those peer addresses during
the start (similarly to the ones in the peerstore).

This allows to provide "bootstrap" (as in "peers we connect to") addresses
directly in the configuration, which is useful when distributing a single
configuration template that will allow a cluster peer to know where to connect
on the first boot.
---
 cluster.go             |  3 ++-
 cluster_config.go      | 22 +++++++++++++++++++++-
 cluster_config_test.go | 10 +++++++++-
 3 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/cluster.go b/cluster.go
index ed06058b..6f6f7325 100644
--- a/cluster.go
+++ b/cluster.go
@@ -165,9 +165,10 @@ func NewCluster(
 		readyB:      false,
 	}
 
-	// Import known cluster peers from peerstore file. Set
+	// Import known cluster peers from peerstore file and config. Set
 	// a non permanent TTL.
 	c.peerManager.ImportPeersFromPeerstore(false, peerstore.AddressTTL)
+	c.peerManager.ImportPeers(c.config.PeerAddresses, false, peerstore.AddressTTL)
 	// Attempt to connect to some peers (up to bootstrapCount)
 	connectedPeers := c.peerManager.Bootstrap(bootstrapCount)
 	// We cannot warn when count is low as this as this is normal if going
diff --git a/cluster_config.go b/cluster_config.go
index bdb39b4f..53b63b34 100644
--- a/cluster_config.go
+++ b/cluster_config.go
@@ -155,6 +155,11 @@ type Config struct {
 	// libp2p host peerstore addresses. This file is regularly saved.
 	PeerstoreFile string
 
+	// PeerAddresses stores additional addresses for peers that may or may
+	// not be in the peerstore file. These are considered high priority
+	// when bootstrapping the initial cluster connections.
+	PeerAddresses []ma.Multiaddr
+
 	// Tracing flag used to skip tracing specific paths when not enabled.
 	Tracing bool
 }
@@ -182,6 +187,7 @@ type configJSON struct {
 	DisableRepinning     bool               `json:"disable_repinning"`
 	FollowerMode         bool               `json:"follower_mode,omitempty"`
 	PeerstoreFile        string             `json:"peerstore_file,omitempty"`
+	PeerAddresses        []string           `json:"peer_addresses"`
 }
 
 // connMgrConfigJSON configures the libp2p host connection manager.
@@ -369,8 +375,9 @@ func (cfg *Config) setDefaults() {
 	cfg.PeerWatchInterval = DefaultPeerWatchInterval
 	cfg.MDNSInterval = DefaultMDNSInterval
 	cfg.DisableRepinning = DefaultDisableRepinning
-	cfg.PeerstoreFile = "" // empty so it gets ommited.
 	cfg.FollowerMode = DefaultFollowerMode
+	cfg.PeerstoreFile = "" // empty so it gets ommited.
+	cfg.PeerAddresses = []ma.Multiaddr{}
 	cfg.RPCPolicy = DefaultRPCPolicy
 }
 
@@ -444,6 +451,16 @@ func (cfg *Config) applyConfigJSON(jcfg *configJSON) error {
 		return err
 	}
 
+	// PeerAddresses
+	for _, addr := range jcfg.PeerAddresses {
+		peerAddr, err := ma.NewMultiaddr(addr)
+		if err != nil {
+			err = fmt.Errorf("error parsing peer_addresses: %s", err)
+			return err
+		}
+		cfg.PeerAddresses = append(cfg.PeerAddresses, peerAddr)
+	}
+
 	cfg.LeaveOnShutdown = jcfg.LeaveOnShutdown
 	cfg.DisableRepinning = jcfg.DisableRepinning
 	cfg.FollowerMode = jcfg.FollowerMode
@@ -497,6 +514,9 @@ func (cfg *Config) toConfigJSON() (jcfg *configJSON, err error) {
 	jcfg.MDNSInterval = cfg.MDNSInterval.String()
 	jcfg.DisableRepinning = cfg.DisableRepinning
 	jcfg.PeerstoreFile = cfg.PeerstoreFile
+	for _, addr := range cfg.PeerAddresses {
+		jcfg.PeerAddresses = append(jcfg.PeerAddresses, addr.String())
+	}
 	jcfg.FollowerMode = cfg.FollowerMode
 
 	return
diff --git a/cluster_config_test.go b/cluster_config_test.go
index 3ca3e120..e30798f9 100644
--- a/cluster_config_test.go
+++ b/cluster_config_test.go
@@ -29,7 +29,8 @@ var ccfgTestJSON = []byte(`
         "replication_factor_min": 5,
         "replication_factor_max": 5,
         "monitor_ping_interval": "2s",
-        "disable_repinning": true
+        "disable_repinning": true,
+        "peer_addresses": [ "/ip4/127.0.0.1/tcp/1234/p2p/QmXZrtE5jQwXNqCJMfHUTQkvhQ4ZAnqMnmzFMJfLewuabc" ]
 }
 `)
 
@@ -92,6 +93,13 @@ func TestLoadJSON(t *testing.T) {
 		}
 	})
 
+	t.Run("expected peer addresses", func(t *testing.T) {
+		cfg := loadJSON(t)
+		if len(cfg.PeerAddresses) != 1 {
+			t.Error("expected 1 peer address")
+		}
+	})
+
 	loadJSON2 := func(t *testing.T, f func(j *configJSON)) (*Config, error) {
 		cfg := &Config{}
 		j := &configJSON{}