Merge pull request #295 from sigp/validator-updates

Persisting (random) Validator Keys

validator_client/Cargo.toml

@@ -4,6 +4,15 @@ version = "0.1.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = "2018"
 
+[[bin]]
+name = "validator_client"
+path = "src/main.rs"
+
+[lib]
+name = "validator_client"
+path = "src/lib.rs"
+
+
 [dependencies]
 block_proposer = { path = "../eth2/block_proposer" }
 bls = { path = "../eth2/utils/bls" }
@@ -18,3 +27,4 @@ slog = "^2.2.3"
 slog-term = "^2.4.0"
 slog-async = "^2.3.0"
 ssz = { path = "../eth2/utils/ssz" }
+bincode = "^1.1.2"

validator_client/README.md

@@ -57,10 +57,30 @@ complete and return a block from the BN.
 
 ### Configuration
 
-Presently the validator specifics (pubkey, etc.) are randomly generated and the
-chain specification (slot length, BLS domain, etc.) are fixed to foundation
-parameters. This is temporary and will be upgrade so these parameters can be
-read from file (or initialized on first-boot).
+Validator configurations are stored in a separate data directory from the main Beacon Node
+binary. The validator data directory defaults to:
+`$HOME/.lighthouse-validator`, however an alternative can be specified on the command line
+with `--datadir`.
+
+The configuration directory structure looks like:
+```
+~/.lighthouse-validator
+    ├── 3cf4210d58ec
+    │   └── private.key
+    ├── 9b5d8b5be4e7
+    │   └── private.key
+    └── cf6e07188f48
+        └── private.key
+```
+
+Where the hex value of the directory is a portion of the validator public key.
+
+Validator keys must be generated using the separate `accounts_manager` binary, which will
+place the keys into this directory structure in a format compatible with the validator client.
+
+The chain specification (slot length, BLS domain, etc.) defaults to foundation
+parameters, however is temporary and an upgrade will allow these parameters to be
+read from a file (or initialized on first-boot).
 
 ## BN Communication
 

validator_client/src/config.rs

@@ -1,28 +1,39 @@
+use bincode;
+use bls::Keypair;
+use clap::ArgMatches;
+use slog::{debug, error, info};
 use std::fs;
+use std::fs::File;
+use std::io::{Error, ErrorKind};
 use std::path::PathBuf;
 use types::ChainSpec;
 
 /// Stores the core configuration for this validator instance.
 #[derive(Clone)]
-pub struct ClientConfig {
+pub struct Config {
+    /// The data directory, which stores all validator databases
     pub data_dir: PathBuf,
+    /// The server at which the Beacon Node can be contacted
     pub server: String,
+    /// The chain specification that we are connecting to
     pub spec: ChainSpec,
 }
 
-const DEFAULT_LIGHTHOUSE_DIR: &str = ".lighthouse-validators";
+const DEFAULT_PRIVATE_KEY_FILENAME: &str = "private.key";
 
-impl ClientConfig {
-    /// Build a new configuration from defaults.
-    pub fn default() -> Self {
+impl Default for Config {
+    fn default() -> Self {
         let data_dir = {
-            let home = dirs::home_dir().expect("Unable to determine home dir.");
-            home.join(DEFAULT_LIGHTHOUSE_DIR)
+            let home = dirs::home_dir().expect("Unable to determine home directory.");
+            home.join(".lighthouse-validator")
         };
         fs::create_dir_all(&data_dir)
             .unwrap_or_else(|_| panic!("Unable to create {:?}", &data_dir));
+
         let server = "localhost:50051".to_string();
+
         let spec = ChainSpec::foundation();
+
         Self {
             data_dir,
             server,
@@ -30,3 +41,114 @@ impl ClientConfig {
         }
     }
 }
+
+impl Config {
+    /// Build a new configuration from defaults, which are overrided by arguments provided.
+    pub fn parse_args(args: &ArgMatches, log: &slog::Logger) -> Result<Self, Error> {
+        let mut config = Config::default();
+
+        // Use the specified datadir, or default in the home directory
+        if let Some(datadir) = args.value_of("datadir") {
+            config.data_dir = PathBuf::from(datadir);
+            fs::create_dir_all(&config.data_dir)
+                .unwrap_or_else(|_| panic!("Unable to create {:?}", &config.data_dir));
+            info!(log, "Using custom data dir: {:?}", &config.data_dir);
+        };
+
+        if let Some(srv) = args.value_of("server") {
+            //TODO: I don't think this parses correctly a server & port combo
+            config.server = srv.to_string();
+            info!(log, "Using custom server: {:?}", &config.server);
+        };
+
+        // TODO: Permit loading a custom spec from file.
+        if let Some(spec_str) = args.value_of("spec") {
+            info!(log, "Using custom spec: {:?}", spec_str);
+            config.spec = match spec_str {
+                "foundation" => ChainSpec::foundation(),
+                "few_validators" => ChainSpec::few_validators(),
+                // Should be impossible due to clap's `possible_values(..)` function.
+                _ => unreachable!(),
+            };
+        };
+
+        Ok(config)
+    }
+
+    /// Try to load keys from validator_dir, returning None if none are found or an error.
+    pub fn fetch_keys(&self, log: &slog::Logger) -> Option<Vec<Keypair>> {
+        let key_pairs: Vec<Keypair> = fs::read_dir(&self.data_dir)
+            .unwrap()
+            .filter_map(|validator_dir| {
+                let validator_dir = validator_dir.ok()?;
+
+                if !(validator_dir.file_type().ok()?.is_dir()) {
+                    // Skip non-directories (i.e. no files/symlinks)
+                    return None;
+                }
+
+                let key_filename = validator_dir.path().join(DEFAULT_PRIVATE_KEY_FILENAME);
+
+                if !(key_filename.is_file()) {
+                    info!(
+                        log,
+                        "Private key is not a file: {:?}",
+                        key_filename.to_str()
+                    );
+                    return None;
+                }
+
+                debug!(
+                    log,
+                    "Deserializing private key from file: {:?}",
+                    key_filename.to_str()
+                );
+
+                let mut key_file = File::open(key_filename.clone()).ok()?;
+
+                let key: Keypair = if let Ok(key_ok) = bincode::deserialize_from(&mut key_file) {
+                    key_ok
+                } else {
+                    error!(
+                        log,
+                        "Unable to deserialize the private key file: {:?}", key_filename
+                    );
+                    return None;
+                };
+
+                let ki = key.identifier();
+                if ki != validator_dir.file_name().into_string().ok()? {
+                    error!(
+                        log,
+                        "The validator key ({:?}) did not match the directory filename {:?}.",
+                        ki,
+                        &validator_dir.path().to_string_lossy()
+                    );
+                    return None;
+                }
+                Some(key)
+            })
+            .collect();
+
+        // Check if it's an empty vector, and return none.
+        if key_pairs.is_empty() {
+            None
+        } else {
+            Some(key_pairs)
+        }
+    }
+
+    /// Saves a keypair to a file inside the appropriate validator directory. Returns the saved path filename.
+    pub fn save_key(&self, key: &Keypair) -> Result<PathBuf, Error> {
+        let validator_config_path = self.data_dir.join(key.identifier());
+        let key_path = validator_config_path.join(DEFAULT_PRIVATE_KEY_FILENAME);
+
+        fs::create_dir_all(&validator_config_path)?;
+
+        let mut key_file = File::create(&key_path)?;
+
+        bincode::serialize_into(&mut key_file, &key)
+            .map_err(|e| Error::new(ErrorKind::InvalidData, e))?;
+        Ok(key_path)
+    }
+}

validator_client/src/lib.rs

@@ -0,0 +1,3 @@
+pub mod config;
+
+pub use crate::config::Config;

validator_client/src/main.rs

@@ -1,17 +1,14 @@
 use self::block_producer_service::{BeaconBlockGrpcClient, BlockProducerService};
 use self::duties::{DutiesManager, DutiesManagerService, EpochDutiesMap};
-use crate::config::ClientConfig;
+use crate::config::Config;
 use block_proposer::{test_utils::LocalSigner, BlockProducer};
-use bls::Keypair;
 use clap::{App, Arg};
 use grpcio::{ChannelBuilder, EnvBuilder};
 use protos::services_grpc::{BeaconBlockServiceClient, ValidatorServiceClient};
-use slog::{error, info, o, Drain};
+use slog::{info, o, Drain};
 use slot_clock::SystemTimeSlotClock;
-use std::path::PathBuf;
 use std::sync::Arc;
 use std::thread;
-use types::ChainSpec;
 
 mod block_producer_service;
 mod config;
@@ -55,36 +52,11 @@ fn main() {
         )
         .get_matches();
 
-    let mut config = ClientConfig::default();
-
-    // Custom datadir
-    if let Some(dir) = matches.value_of("datadir") {
-        config.data_dir = PathBuf::from(dir.to_string());
-    }
-
-    // Custom server port
-    if let Some(server_str) = matches.value_of("server") {
-        if let Ok(addr) = server_str.parse::<u16>() {
-            config.server = addr.to_string();
-        } else {
-            error!(log, "Invalid address"; "server" => server_str);
-            return;
-        }
-    }
-
-    // TODO: Permit loading a custom spec from file.
-    // Custom spec
-    if let Some(spec_str) = matches.value_of("spec") {
-        match spec_str {
-            "foundation" => config.spec = ChainSpec::foundation(),
-            "few_validators" => config.spec = ChainSpec::few_validators(),
-            // Should be impossible due to clap's `possible_values(..)` function.
-            _ => unreachable!(),
-        };
-    }
+    let config = Config::parse_args(&matches, &log)
+        .expect("Unable to build a configuration for the validator client.");
 
     // Log configuration
-    info!(log, "";
+    info!(log, "Configuration parameters:";
           "data_dir" => &config.data_dir.to_str(),
           "server" => &config.server);
 
@@ -119,13 +91,13 @@ fn main() {
     let poll_interval_millis = spec.seconds_per_slot * 1000 / 10; // 10% epoch time precision.
     info!(log, "Starting block producer service"; "polls_per_epoch" => spec.seconds_per_slot * 1000 / poll_interval_millis);
 
+    let keypairs = config.fetch_keys(&log)
+        .expect("No key pairs found in configuration, they must first be generated with: account_manager generate.");
+
     /*
      * Start threads.
      */
     let mut threads = vec![];
-    // TODO: keypairs are randomly generated; they should be loaded from a file or generated.
-    // https://github.com/sigp/lighthouse/issues/160
-    let keypairs = vec![Keypair::random()];
 
     for keypair in keypairs {
         info!(log, "Starting validator services"; "validator" => keypair.pk.concatenated_hex_id());