aboutsummaryrefslogtreecommitdiff
path: root/src/rpc/system.rs
blob: f5ce817f3d322e930c8bd0cb691c74e802a30a05 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
//! Module containing structs related to membership management
use std::collections::HashMap;
use std::io::{Read, Write};
use std::net::SocketAddr;
use std::path::Path;
use std::sync::{Arc, RwLock};
use std::time::{Duration, Instant};

use arc_swap::ArcSwap;
use async_trait::async_trait;
use futures::{join, select};
use futures_util::future::*;
use serde::{Deserialize, Serialize};
use sodiumoxide::crypto::sign::ed25519;
use tokio::sync::watch;
use tokio::sync::Mutex;

use netapp::endpoint::{Endpoint, EndpointHandler};
use netapp::peering::fullmesh::FullMeshPeeringStrategy;
use netapp::proto::*;
use netapp::util::parse_and_resolve_peer_addr;
use netapp::{NetApp, NetworkKey, NodeID, NodeKey};

use garage_util::background::BackgroundRunner;
use garage_util::config::Config;
use garage_util::data::Uuid;
use garage_util::error::*;
use garage_util::persister::Persister;
use garage_util::time::*;

use crate::consul::*;
use crate::ring::*;
use crate::rpc_helper::*;

const DISCOVERY_INTERVAL: Duration = Duration::from_secs(60);
const STATUS_EXCHANGE_INTERVAL: Duration = Duration::from_secs(10);
const PING_TIMEOUT: Duration = Duration::from_secs(2);

/// RPC endpoint used for calls related to membership
pub const SYSTEM_RPC_PATH: &str = "garage_rpc/membership.rs/SystemRpc";

pub const CONNECT_ERROR_MESSAGE: &str = "Error establishing RPC connection to remote node. This can happen if the remote node is not reachable on the network, but also if the two nodes are not configured with the same rpc_secret";

/// RPC messages related to membership
#[derive(Debug, Serialize, Deserialize, Clone)]
pub enum SystemRpc {
	/// Response to successfull advertisements
	Ok,
	/// Request to connect to a specific node (in <pubkey>@<host>:<port> format)
	Connect(String),
	/// Ask other node its config. Answered with AdvertiseConfig
	PullConfig,
	/// Advertise Garage status. Answered with another AdvertiseStatus.
	/// Exchanged with every node on a regular basis.
	AdvertiseStatus(NodeStatus),
	/// Advertisement of nodes config. Sent spontanously or in response to PullConfig
	AdvertiseConfig(NetworkConfig),
	/// Get known nodes states
	GetKnownNodes,
	/// Return known nodes
	ReturnKnownNodes(Vec<KnownNodeInfo>),
}

impl Rpc for SystemRpc {
	type Response = Result<SystemRpc, Error>;
}

/// This node's membership manager
pub struct System {
	/// The id of this node
	pub id: Uuid,

	persist_config: Persister<NetworkConfig>,
	persist_peer_list: Persister<Vec<(Uuid, SocketAddr)>>,

	local_status: ArcSwap<NodeStatus>,
	node_status: RwLock<HashMap<Uuid, (u64, NodeStatus)>>,

	pub netapp: Arc<NetApp>,
	fullmesh: Arc<FullMeshPeeringStrategy>,
	pub rpc: RpcHelper,

	system_endpoint: Arc<Endpoint<SystemRpc, System>>,

	rpc_listen_addr: SocketAddr,
	rpc_public_addr: Option<SocketAddr>,
	bootstrap_peers: Vec<(NodeID, SocketAddr)>,
	consul_host: Option<String>,
	consul_service_name: Option<String>,
	replication_factor: usize,

	/// The ring
	pub ring: watch::Receiver<Arc<Ring>>,
	update_ring: Mutex<watch::Sender<Arc<Ring>>>,

	/// The job runner of this node
	pub background: Arc<BackgroundRunner>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NodeStatus {
	/// Hostname of the node
	pub hostname: String,
	/// Replication factor configured on the node
	pub replication_factor: usize,
	/// Configuration version
	pub config_version: u64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct KnownNodeInfo {
	pub id: Uuid,
	pub addr: SocketAddr,
	pub is_up: bool,
	pub last_seen_secs_ago: Option<u64>,
	pub status: NodeStatus,
}

pub fn read_node_id(metadata_dir: &Path) -> Result<NodeID, Error> {
	let mut pubkey_file = metadata_dir.to_path_buf();
	pubkey_file.push("node_key.pub");

	let mut f = std::fs::File::open(pubkey_file.as_path())?;
	let mut d = vec![];
	f.read_to_end(&mut d)?;
	if d.len() != 32 {
		return Err(Error::Message("Corrupt node_key.pub file".to_string()));
	}

	let mut key = [0u8; 32];
	key.copy_from_slice(&d[..]);
	Ok(NodeID::from_slice(&key[..]).unwrap())
}

pub fn gen_node_key(metadata_dir: &Path) -> Result<NodeKey, Error> {
	let mut key_file = metadata_dir.to_path_buf();
	key_file.push("node_key");
	if key_file.as_path().exists() {
		let mut f = std::fs::File::open(key_file.as_path())?;
		let mut d = vec![];
		f.read_to_end(&mut d)?;
		if d.len() != 64 {
			return Err(Error::Message("Corrupt node_key file".to_string()));
		}

		let mut key = [0u8; 64];
		key.copy_from_slice(&d[..]);
		Ok(NodeKey::from_slice(&key[..]).unwrap())
	} else {
		if !metadata_dir.exists() {
			info!("Metadata directory does not exist, creating it.");
			std::fs::create_dir(&metadata_dir)?;
		}

		info!("Generating new node key pair.");
		let (pubkey, key) = ed25519::gen_keypair();

		{
			use std::os::unix::fs::PermissionsExt;
			let mut f = std::fs::File::create(key_file.as_path())?;
			let mut perm = f.metadata()?.permissions();
			perm.set_mode(0o600);
			std::fs::set_permissions(key_file.as_path(), perm)?;
			f.write_all(&key[..])?;
		}

		{
			let mut pubkey_file = metadata_dir.to_path_buf();
			pubkey_file.push("node_key.pub");
			let mut f2 = std::fs::File::create(pubkey_file.as_path())?;
			f2.write_all(&pubkey[..])?;
		}

		Ok(key)
	}
}

impl System {
	/// Create this node's membership manager
	pub fn new(
		network_key: NetworkKey,
		background: Arc<BackgroundRunner>,
		replication_factor: usize,
		config: &Config,
	) -> Arc<Self> {
		let node_key =
			gen_node_key(&config.metadata_dir).expect("Unable to read or generate node ID");
		info!("Node public key: {}", hex::encode(&node_key.public_key()));

		let persist_config = Persister::new(&config.metadata_dir, "network_config");
		let persist_peer_list = Persister::new(&config.metadata_dir, "peer_list");

		let net_config = match persist_config.load() {
			Ok(x) => x,
			Err(e) => {
				info!(
					"No valid previous network configuration stored ({}), starting fresh.",
					e
				);
				NetworkConfig::new()
			}
		};

		let local_status = NodeStatus {
			hostname: gethostname::gethostname()
				.into_string()
				.unwrap_or_else(|_| "<invalid utf-8>".to_string()),
			replication_factor,
			config_version: net_config.version,
		};

		let ring = Ring::new(net_config, replication_factor);
		let (update_ring, ring) = watch::channel(Arc::new(ring));

		if let Some(addr) = config.rpc_public_addr {
			println!("{}@{}", hex::encode(&node_key.public_key()), addr);
		} else {
			println!("{}", hex::encode(&node_key.public_key()));
		}

		let netapp = NetApp::new(network_key, node_key);
		let fullmesh = FullMeshPeeringStrategy::new(
			netapp.clone(),
			config.bootstrap_peers.clone(),
			config.rpc_public_addr,
		);

		let system_endpoint = netapp.endpoint(SYSTEM_RPC_PATH.into());

		let sys = Arc::new(System {
			id: netapp.id.into(),
			persist_config,
			persist_peer_list,
			local_status: ArcSwap::new(Arc::new(local_status)),
			node_status: RwLock::new(HashMap::new()),
			netapp: netapp.clone(),
			fullmesh: fullmesh.clone(),
			rpc: RpcHelper {
				fullmesh,
				background: background.clone(),
			},
			system_endpoint,
			replication_factor,
			rpc_listen_addr: config.rpc_bind_addr,
			rpc_public_addr: config.rpc_public_addr,
			bootstrap_peers: config.bootstrap_peers.clone(),
			consul_host: config.consul_host.clone(),
			consul_service_name: config.consul_service_name.clone(),
			ring,
			update_ring: Mutex::new(update_ring),
			background,
		});
		sys.system_endpoint.set_handler(sys.clone());
		sys
	}

	/// Perform bootstraping, starting the ping loop
	pub async fn run(self: Arc<Self>, must_exit: watch::Receiver<bool>) {
		join!(
			self.netapp
				.clone()
				.listen(self.rpc_listen_addr, None, must_exit.clone()),
			self.fullmesh.clone().run(must_exit.clone()),
			self.discovery_loop(must_exit.clone()),
			self.status_exchange_loop(must_exit.clone()),
		);
	}

	// ---- INTERNALS ----

	async fn advertise_to_consul(self: Arc<Self>) -> Result<(), Error> {
		let (consul_host, consul_service_name) =
			match (&self.consul_host, &self.consul_service_name) {
				(Some(ch), Some(csn)) => (ch, csn),
				_ => return Ok(()),
			};

		let rpc_public_addr = match self.rpc_public_addr {
			Some(addr) => addr,
			None => {
				warn!("Not advertising to Consul because rpc_public_addr is not defined in config file.");
				return Ok(());
			}
		};

		publish_consul_service(
			consul_host,
			consul_service_name,
			self.netapp.id,
			&self.local_status.load_full().hostname,
			rpc_public_addr,
		)
		.await
		.err_context("Error while publishing Consul service")
	}

	/// Save network configuration to disc
	async fn save_network_config(self: Arc<Self>) -> Result<(), Error> {
		let ring: Arc<Ring> = self.ring.borrow().clone();
		self.persist_config
			.save_async(&ring.config)
			.await
			.expect("Cannot save current cluster configuration");
		Ok(())
	}

	fn update_local_status(&self) {
		let mut new_si: NodeStatus = self.local_status.load().as_ref().clone();

		let ring = self.ring.borrow();
		new_si.config_version = ring.config.version;
		self.local_status.swap(Arc::new(new_si));
	}

	async fn handle_connect(&self, node: &str) -> Result<SystemRpc, Error> {
		let (pubkey, addrs) = parse_and_resolve_peer_addr(node).ok_or_else(|| {
			Error::Message(format!(
				"Unable to parse or resolve node specification: {}",
				node
			))
		})?;
		let mut errors = vec![];
		for ip in addrs.iter() {
			match self
				.netapp
				.clone()
				.try_connect(*ip, pubkey)
				.await
				.err_context(CONNECT_ERROR_MESSAGE)
			{
				Ok(()) => return Ok(SystemRpc::Ok),
				Err(e) => {
					errors.push((*ip, e));
				}
			}
		}
		return Err(Error::Message(format!(
			"Could not connect to specified peers. Errors: {:?}",
			errors
		)));
	}

	fn handle_pull_config(&self) -> SystemRpc {
		let ring = self.ring.borrow().clone();
		SystemRpc::AdvertiseConfig(ring.config.clone())
	}

	fn handle_get_known_nodes(&self) -> SystemRpc {
		let node_status = self.node_status.read().unwrap();
		let known_nodes = self
			.fullmesh
			.get_peer_list()
			.iter()
			.map(|n| KnownNodeInfo {
				id: n.id.into(),
				addr: n.addr,
				is_up: n.is_up(),
				last_seen_secs_ago: n.last_seen.map(|t| (Instant::now() - t).as_secs()),
				status: node_status
					.get(&n.id.into())
					.cloned()
					.map(|(_, st)| st)
					.unwrap_or(NodeStatus {
						hostname: "?".to_string(),
						replication_factor: 0,
						config_version: 0,
					}),
			})
			.collect::<Vec<_>>();
		SystemRpc::ReturnKnownNodes(known_nodes)
	}

	async fn handle_advertise_status(
		self: &Arc<Self>,
		from: Uuid,
		info: &NodeStatus,
	) -> Result<SystemRpc, Error> {
		let local_info = self.local_status.load();

		if local_info.replication_factor < info.replication_factor {
			error!("Some node have a higher replication factor ({}) than this one ({}). This is not supported and might lead to bugs",
				info.replication_factor,
				local_info.replication_factor);
			std::process::exit(1);
		}

		if info.config_version > local_info.config_version {
			let self2 = self.clone();
			self.background.spawn_cancellable(async move {
				self2.pull_config(from).await;
				Ok(())
			});
		}

		self.node_status
			.write()
			.unwrap()
			.insert(from, (now_msec(), info.clone()));

		Ok(SystemRpc::Ok)
	}

	async fn handle_advertise_config(
		self: Arc<Self>,
		adv: &NetworkConfig,
	) -> Result<SystemRpc, Error> {
		let update_ring = self.update_ring.lock().await;
		let ring: Arc<Ring> = self.ring.borrow().clone();

		if adv.version > ring.config.version {
			let ring = Ring::new(adv.clone(), self.replication_factor);
			update_ring.send(Arc::new(ring))?;
			drop(update_ring);

			let self2 = self.clone();
			let adv = adv.clone();
			self.background.spawn_cancellable(async move {
				self2
					.rpc
					.broadcast(
						&self2.system_endpoint,
						SystemRpc::AdvertiseConfig(adv),
						RequestStrategy::with_priority(PRIO_HIGH),
					)
					.await;
				Ok(())
			});
			self.background.spawn(self.clone().save_network_config());
		}

		Ok(SystemRpc::Ok)
	}

	async fn status_exchange_loop(&self, mut stop_signal: watch::Receiver<bool>) {
		while !*stop_signal.borrow() {
			let restart_at = tokio::time::sleep(STATUS_EXCHANGE_INTERVAL);

			self.update_local_status();
			let local_status: NodeStatus = self.local_status.load().as_ref().clone();
			self.rpc
				.broadcast(
					&self.system_endpoint,
					SystemRpc::AdvertiseStatus(local_status),
					RequestStrategy::with_priority(PRIO_HIGH).with_timeout(PING_TIMEOUT),
				)
				.await;

			select! {
				_ = restart_at.fuse() => {},
				_ = stop_signal.changed().fuse() => {},
			}
		}
	}

	async fn discovery_loop(self: &Arc<Self>, mut stop_signal: watch::Receiver<bool>) {
		let consul_config = match (&self.consul_host, &self.consul_service_name) {
			(Some(ch), Some(csn)) => Some((ch.clone(), csn.clone())),
			_ => None,
		};

		while !*stop_signal.borrow() {
			let not_configured = self.ring.borrow().config.members.is_empty();
			let no_peers = self.fullmesh.get_peer_list().len() < self.replication_factor;
			let bad_peers = self
				.fullmesh
				.get_peer_list()
				.iter()
				.filter(|p| p.is_up())
				.count() != self.ring.borrow().config.members.len();

			if not_configured || no_peers || bad_peers {
				info!("Doing a bootstrap/discovery step (not_configured: {}, no_peers: {}, bad_peers: {})", not_configured, no_peers, bad_peers);

				let mut ping_list = self.bootstrap_peers.clone();

				// Add peer list from list stored on disk
				if let Ok(peers) = self.persist_peer_list.load_async().await {
					ping_list.extend(peers.iter().map(|(id, addr)| ((*id).into(), *addr)))
				}

				// Fetch peer list from Consul
				if let Some((consul_host, consul_service_name)) = &consul_config {
					match get_consul_nodes(consul_host, consul_service_name).await {
						Ok(node_list) => {
							ping_list.extend(node_list);
						}
						Err(e) => {
							warn!("Could not retrieve node list from Consul: {}", e);
						}
					}
				}

				for (node_id, node_addr) in ping_list {
					tokio::spawn(
						self.netapp
							.clone()
							.try_connect(node_addr, node_id)
							.map(|r| r.err_context(CONNECT_ERROR_MESSAGE)),
					);
				}
			}

			let peer_list = self
				.fullmesh
				.get_peer_list()
				.iter()
				.map(|n| (n.id.into(), n.addr))
				.collect::<Vec<_>>();
			if let Err(e) = self.persist_peer_list.save_async(&peer_list).await {
				warn!("Could not save peer list to file: {}", e);
			}

			self.background.spawn(self.clone().advertise_to_consul());

			let restart_at = tokio::time::sleep(DISCOVERY_INTERVAL);
			select! {
				_ = restart_at.fuse() => {},
				_ = stop_signal.changed().fuse() => {},
			}
		}
	}

	async fn pull_config(self: Arc<Self>, peer: Uuid) {
		let resp = self
			.rpc
			.call(
				&self.system_endpoint,
				peer,
				SystemRpc::PullConfig,
				RequestStrategy::with_priority(PRIO_HIGH).with_timeout(PING_TIMEOUT),
			)
			.await;
		if let Ok(SystemRpc::AdvertiseConfig(config)) = resp {
			let _: Result<_, _> = self.handle_advertise_config(&config).await;
		}
	}
}

#[async_trait]
impl EndpointHandler<SystemRpc> for System {
	async fn handle(self: &Arc<Self>, msg: &SystemRpc, from: NodeID) -> Result<SystemRpc, Error> {
		match msg {
			SystemRpc::Connect(node) => self.handle_connect(node).await,
			SystemRpc::PullConfig => Ok(self.handle_pull_config()),
			SystemRpc::AdvertiseStatus(adv) => self.handle_advertise_status(from.into(), adv).await,
			SystemRpc::AdvertiseConfig(adv) => self.clone().handle_advertise_config(&adv).await,
			SystemRpc::GetKnownNodes => Ok(self.handle_get_known_nodes()),
			_ => Err(Error::BadRpc("Unexpected RPC message".to_string())),
		}
	}
}