Introduce a ChainScanner to scan the chains for clients, connection…

…s and channels

modules/src/core/ics03_connection/connection.rs

@@ -2,7 +2,7 @@ use crate::prelude::*;
 
 use core::str::FromStr;
 use core::time::Duration;
-use core::u64;
+use core::{fmt, u64};
 
 use serde::{Deserialize, Serialize};
 use tendermint_proto::Protobuf;
@@ -323,15 +323,16 @@ pub enum State {
 
 impl State {
     /// Yields the State as a string.
-    pub fn as_string(&self) -> &'static str {
+    pub fn as_str(&self) -> &'static str {
         match self {
             Self::Uninitialized => "UNINITIALIZED",
             Self::Init => "INIT",
             Self::TryOpen => "TRYOPEN",
             Self::Open => "OPEN",
         }
     }
-    // Parses the State out from a i32.
+
+    /// Parses the State out from a i32.
     pub fn from_i32(s: i32) -> Result<Self, Error> {
         match s {
             0 => Ok(Self::Uninitialized),
@@ -361,6 +362,12 @@ impl State {
     }
 }
 
+impl fmt::Display for State {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.as_str())
+    }
+}
+
 impl TryFrom<i32> for State {
     type Error = Error;
     fn try_from(value: i32) -> Result<Self, Self::Error> {

relayer/src/chain/counterparty.rs

@@ -73,7 +73,7 @@ fn connection_on_destination(
 }
 
 pub fn connection_state_on_destination(
-    connection: IdentifiedConnectionEnd,
+    connection: &IdentifiedConnectionEnd,
     counterparty_chain: &impl ChainHandle,
 ) -> Result<ConnectionState, Error> {
     if let Some(remote_connection_id) = connection.connection_end.counterparty().connection_id() {

relayer/src/connection.rs

@@ -602,7 +602,7 @@ impl<ChainA: ChainHandle, ChainB: ChainHandle> Connection<ChainA, ChainB> {
             connection_id: connection_id.clone(),
         };
 
-        connection_state_on_destination(connection, &self.dst_chain())
+        connection_state_on_destination(&connection, &self.dst_chain())
             .map_err(ConnectionError::supervisor)
     }
 

relayer/src/supervisor.rs

@@ -36,12 +36,14 @@ pub mod dump_state;
 use dump_state::SupervisorState;
 
 pub mod spawn;
-use spawn::SpawnContext;
+use spawn::{SpawnContext, SpawnMode};
+
+pub mod scan;
 
 pub mod cmd;
 use cmd::{CmdEffect, ConfigUpdate, SupervisorCmd};
 
-use self::spawn::SpawnMode;
+use self::scan::ChainsScan;
 
 type ArcBatch = Arc<event::monitor::Result<EventBatch>>;
 type Subscription = Receiver<ArcBatch>;
@@ -332,8 +334,22 @@ impl<Chain: ChainHandle + 'static> Supervisor<Chain> {
 
     /// Spawn all the workers necessary for the relayer to connect
     /// and relay between all the chains in the configurations.
-    fn spawn_workers(&mut self, mode: SpawnMode) {
-        self.spawn_context(mode).spawn_workers();
+    fn spawn_workers(&mut self, scan: ChainsScan, mode: SpawnMode) {
+        self.spawn_context(mode).spawn_workers(scan);
+    }
+
+    fn scan(&mut self) -> ChainsScan {
+        use self::scan::ChainScanner;
+
+        let mut scanner = ChainScanner::new(
+            self.config.read().unwrap().clone(),
+            self.registry.clone(),
+            &mut self.client_state_filter,
+        );
+
+        let scan = scanner.scan_chains();
+        println!("{}", scan);
+        scan
     }
 
     /// Perform a health check on all connected chains
@@ -413,7 +429,9 @@ impl<Chain: ChainHandle + 'static> Supervisor<Chain> {
     }
 
     pub fn run_without_health_check(&mut self) -> Result<(), Error> {
-        self.spawn_workers(SpawnMode::Startup);
+        let scan = self.scan();
+
+        self.spawn_workers(scan, SpawnMode::Startup);
 
         let mut subscriptions = self.init_subscriptions()?;
 

relayer/src/supervisor/error.rs

@@ -5,6 +5,7 @@ use ibc::core::ics24_host::identifier::{ChainId, ChannelId, ConnectionId, PortId
 
 use crate::error::Error as RelayerError;
 use crate::registry::SpawnError;
+use crate::supervisor::scan::Error as ScanError;
 use crate::worker::WorkerError;
 
 define_error! {
@@ -66,6 +67,10 @@ define_error! {
             [ SpawnError ]
             |_| { "supervisor was not able to connect to any chains" },
 
+        Scan
+            [ ScanError ]
+            |_| { "supervisor encountered an error when scanning chains" },
+
         Worker
             [ WorkerError ]
             |_| { "worker error" },