feat: Add RocksDB snapshot download RPC API with streaming support

.ethexe.example.local.toml

@@ -184,6 +184,26 @@ block-time = 1
 # (optional, default: false).
 # no-rpc = false
 
+# Flag to enable RocksDB snapshot download RPC API.
+# (optional, default: false).
+# snapshot = false
+
+# Bearer token used by `snapshot_download`.
+# Must be provided when `snapshot = true`.
+# snapshot-token = "replace-with-strong-random-token"
+
+# Snapshot stream chunk size in bytes.
+# (optional, default: 1048576).
+# snapshot-chunk-bytes = 1048576
+
+# Snapshot artifact retention in seconds.
+# (optional, default: 600).
+# snapshot-retention-secs = 600
+
+# Maximum concurrent snapshot downloads.
+# (optional, default: 1).
+# snapshot-max-concurrent = 1
+
 ##########################################################################################
 
 ### Prometheus (metrics) service parameters.

.ethexe.example.toml

@@ -184,6 +184,26 @@
 # (optional, default: false).
 # no-rpc = false
 
+# Flag to enable RocksDB snapshot download RPC API.
+# (optional, default: false).
+# snapshot = false
+
+# Bearer token used by `snapshot_download`.
+# Must be provided when `snapshot = true`.
+# snapshot-token = "replace-with-strong-random-token"
+
+# Snapshot stream chunk size in bytes.
+# (optional, default: 1048576).
+# snapshot-chunk-bytes = 1048576
+
+# Snapshot artifact retention in seconds.
+# (optional, default: 600).
+# snapshot-retention-secs = 600
+
+# Maximum concurrent snapshot downloads.
+# (optional, default: 1).
+# snapshot-max-concurrent = 1
+
 ##########################################################################################
 
 ### Prometheus (metrics) service parameters.

ethexe/cli/src/params/mod.rs

@@ -93,7 +93,10 @@ impl Params {
                     .transpose()
             })
             .transpose()?;
-        let rpc = rpc.and_then(|p| p.into_config(&node));
+        let rpc = match rpc {
+            Some(params) => params.into_config(&node)?,
+            None => None,
+        };
         let prometheus = prometheus.and_then(|p| p.into_config());
         Ok(Config {
             node,