feat: Add gateway_url to EN config (#2698)

## What ❔

<!-- What are the changes this PR brings about? -->
<!-- Example: This PR adds a PR template to the repo. -->
<!-- (For bigger PRs adding more context is appreciated) -->

## Why ❔

<!-- Why are these changes done? What goal do they contribute to? What
are the principles behind them? -->
<!-- Example: PR templates ensure PR reviewers, observers, and future
iterators are in context about the evolution of repos. -->

## Checklist

<!-- Check your PR fulfills the following items. -->
<!-- For draft PRs check the boxes as you complete them. -->

- [ ] PR title corresponds to the body of PR (we generate changelog
entries from PRs).
- [ ] Tests for the changes have been added / updated.
- [ ] Documentation comments have been added / updated.
- [ ] Code has been formatted via `zk fmt` and `zk lint`.

core/bin/external_node/src/config/mod.rs

@@ -439,6 +439,9 @@ pub(crate) struct OptionalENConfig {
     /// If set to 0, L1 batches will not be retained based on their timestamp. The default value is 7 days.
     #[serde(default = "OptionalENConfig::default_pruning_data_retention_sec")]
     pruning_data_retention_sec: u64,
+    /// Gateway RPC URL, needed for operating during migration.
+    #[allow(dead_code)]
+    pub gateway_url: Option<SensitiveUrl>,
 }
 
 impl OptionalENConfig {
@@ -663,6 +666,7 @@ impl OptionalENConfig {
                 .unwrap_or_else(Self::default_main_node_rate_limit_rps),
             api_namespaces,
             contracts_diamond_proxy_addr: None,
+            gateway_url: enconfig.gateway_url.clone(),
         })
     }
 

core/lib/config/src/configs/en_config.rs

@@ -17,4 +17,6 @@ pub struct ENConfig {
     // Main node configuration
     pub main_node_url: SensitiveUrl,
     pub main_node_rate_limit_rps: Option<NonZeroUsize>,
+
+    pub gateway_url: Option<SensitiveUrl>,
 }

core/lib/config/src/testonly.rs

@@ -928,6 +928,8 @@ impl Distribution<configs::en_config::ENConfig> for EncodeDist {
                 _ => L1BatchCommitmentMode::Validium,
             },
             main_node_rate_limit_rps: self.sample_opt(|| rng.gen()),
+            gateway_url: self
+                .sample_opt(|| format!("localhost:{}", rng.gen::<u16>()).parse().unwrap()),
         }
     }
 }

core/lib/protobuf_config/src/en.rs

@@ -31,6 +31,11 @@ impl ProtoRepr for proto::ExternalNode {
             main_node_rate_limit_rps: self
                 .main_node_rate_limit_rps
                 .and_then(|a| NonZeroUsize::new(a as usize)),
+            gateway_url: self
+                .gateway_url
+                .as_ref()
+                .map(|a| a.parse().context("gateway_url"))
+                .transpose()?,
         })
     }
 
@@ -46,6 +51,10 @@ impl ProtoRepr for proto::ExternalNode {
                 .into(),
             ),
             main_node_rate_limit_rps: this.main_node_rate_limit_rps.map(|a| a.get() as u64),
+            gateway_url: this
+                .gateway_url
+                .as_ref()
+                .map(|a| a.expose_str().to_string()),
         }
     }
 }

core/lib/protobuf_config/src/proto/config/en.proto

@@ -9,4 +9,5 @@ message ExternalNode {
   optional uint64 l1_chain_id = 3; // required
   optional uint64 main_node_rate_limit_rps = 6; // optional
   optional config.genesis.L1BatchCommitDataGeneratorMode l1_batch_commit_data_generator_mode = 7; // optional, default to rollup
+  optional string gateway_url = 8; // optional
 }

etc/env/configs/ext-node.toml

@@ -50,6 +50,9 @@ file_backed_base_path = "artifacts"
 [en.main_node]
 url = "http://127.0.0.1:3050"
 
+[en.gateway]
+url = "http://127.0.0.1:3052"
+
 [rust]
 # `RUST_LOG` environment variable for `env_logger`
 # Here we use TOML multiline strings: newlines will be trimmed.

etc/env/file_based/external_node.yaml

@@ -4,3 +4,5 @@ l1_batch_commit_data_generator_mode: Rollup
 
 main_node_url: http://localhost:3050
 main_node_rate_limit_rps: 1000
+
+gateway_url: http://localhost:3052

zk_toolbox/crates/zk_inception/src/commands/external_node/prepare_configs.rs

@@ -61,6 +61,7 @@ fn prepare_configs(
                 .http_url,
         )?,
         main_node_rate_limit_rps: None,
+        gateway_url: None,
     };
     let mut general_en = general.clone();