Support tips for public mempool submission (#3041)

# Description
We had issues with submitting solutions on arbitrum whenever the gas
prices went above the 0.01 Gwei it usually is. To address that we
configured an additional tip. That worked well while we submitted via
`merkle`. Since we stopped using `merkle` we see a bunch of
[errors](https://aws-es.cow.fi/_dashboards/app/data-explorer/discover#?_a=(discover:(columns:!(log,log_level),isDirty:!f,sort:!()),metadata:(indexPattern:'86e4a5a0-4e4b-11ef-85c5-3946a99ed1a7',view:discover))&_g=(filters:!(),refreshInterval:(pause:!t,value:0),time:(from:'2024-09-08T19:45:08.598Z',to:'2024-10-08T01:21:43.919Z'))&_q=(filters:!(),query:(language:kuery,query:'%22gas:%20max%20fee%20per%20gas%20less%20than%20block%20base%20fee%22%20AND%20%22arbitrum%22')))
indicating that we provide a too low gas price for the transactions.
Turns out we only have the ability to configure additional tips using
private mempools but not with the public mempool. That's way we stopped
seeing those errors while `merkle` was active.

# Changes
Added the ability to also configure gas price tips when submitting via
public mempool.

Will create the necessary follow up PR afterwards.

## How to test
Compiler

crates/driver/example.toml

@@ -20,7 +20,8 @@ gas-price-cap = "1000000000000"
 
 [[submission.mempool]]
 mempool = "public"
-revert-protection = true
+max-additional-tip = "5000000000"
+additional-tip-percentage = 0.05
 
 [[submission.mempool]]
 mempool = "mev-blocker"

crates/driver/src/domain/mempools.rs

@@ -66,7 +66,10 @@ impl Mempools {
         if self.mempools.iter().any(|mempool| {
             matches!(
                 mempool.config().kind,
-                infra::mempool::Kind::Public(infra::mempool::RevertProtection::Disabled)
+                infra::mempool::Kind::Public {
+                    revert_protection: infra::mempool::RevertProtection::Disabled,
+                    ..
+                }
             )
         }) {
             RevertProtection::Disabled

crates/driver/src/infra/blockchain/gas.rs

@@ -39,13 +39,17 @@ impl GasPriceEstimator {
         };
         let additional_tip = mempools
             .iter()
-            .filter_map(|mempool| match mempool.kind {
+            .map(|mempool| match mempool.kind {
                 mempool::Kind::MEVBlocker {
                     max_additional_tip,
                     additional_tip_percentage,
                     ..
-                } => Some((max_additional_tip, additional_tip_percentage)),
-                mempool::Kind::Public(_) => None,
+                } => (max_additional_tip, additional_tip_percentage),
+                mempool::Kind::Public {
+                    max_additional_tip,
+                    additional_tip_percentage,
+                    ..
+                } => (max_additional_tip, additional_tip_percentage),
             })
             .next();
         // Use the lowest max_fee_per_gas of all mempools as the max_fee_per_gas

crates/driver/src/infra/config/file/load.rs

@@ -264,22 +264,29 @@ pub async fn load(chain: eth::ChainId, path: &Path) -> infra::Config {
                 target_confirm_time: config.submission.target_confirm_time,
                 retry_interval: config.submission.retry_interval,
                 kind: match mempool {
-                    file::Mempool::Public => {
+                    file::Mempool::Public {
+                        max_additional_tip,
+                        additional_tip_percentage,
+                    } => {
                         // If there is no private mempool, revert protection is
                         // disabled, otherwise driver would not even try to settle revertable
                         // settlements
-                        mempool::Kind::Public(
-                            if config
-                                .submission
-                                .mempools
-                                .iter()
-                                .any(|pool| matches!(pool, file::Mempool::MevBlocker { .. }))
-                            {
-                                mempool::RevertProtection::Enabled
-                            } else {
-                                mempool::RevertProtection::Disabled
-                            },
-                        )
+                        let revert_protection = if config
+                            .submission
+                            .mempools
+                            .iter()
+                            .any(|pool| matches!(pool, file::Mempool::MevBlocker { .. }))
+                        {
+                            mempool::RevertProtection::Enabled
+                        } else {
+                            mempool::RevertProtection::Disabled
+                        };
+
+                        mempool::Kind::Public {
+                            max_additional_tip: *max_additional_tip,
+                            additional_tip_percentage: *additional_tip_percentage,
+                            revert_protection,
+                        }
                     }
                     file::Mempool::MevBlocker {
                         url,

crates/driver/src/infra/config/file/mod.rs

@@ -104,7 +104,19 @@ struct SubmissionConfig {
 #[serde(tag = "mempool")]
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
 enum Mempool {
-    Public,
+    #[serde(rename_all = "kebab-case")]
+    Public {
+        /// Maximum additional tip in Gwei that we are willing to pay
+        /// above regular gas price estimation.
+        #[serde(default = "default_max_additional_tip")]
+        #[serde_as(as = "serialize::U256")]
+        max_additional_tip: eth::U256,
+        /// Additional tip in percentage of max_fee_per_gas we are willing to
+        /// pay above regular gas price estimation. Expects a
+        /// floating point value between 0 and 1.
+        #[serde(default = "default_additional_tip_percentage")]
+        additional_tip_percentage: f64,
+    },
     #[serde(rename_all = "kebab-case")]
     MevBlocker {
         /// The MEVBlocker URL to use.

crates/driver/src/infra/mempool/mod.rs

@@ -19,7 +19,11 @@ pub struct Config {
 #[derive(Debug, Clone)]
 pub enum Kind {
     /// The public mempool of the [`Ethereum`] node.
-    Public(RevertProtection),
+    Public {
+        max_additional_tip: eth::U256,
+        additional_tip_percentage: f64,
+        revert_protection: RevertProtection,
+    },
     /// The MEVBlocker private mempool.
     MEVBlocker {
         url: reqwest::Url,
@@ -33,7 +37,7 @@ impl Kind {
     /// for instrumentization purposes
     pub fn format_variant(&self) -> &'static str {
         match self {
-            Kind::Public(_) => "PublicMempool",
+            Kind::Public { .. } => "PublicMempool",
             Kind::MEVBlocker { .. } => "MEVBlocker",
         }
     }
@@ -65,7 +69,7 @@ impl std::fmt::Display for Mempool {
 impl Mempool {
     pub fn new(config: Config, transport: DynWeb3) -> Self {
         let transport = match &config.kind {
-            Kind::Public(_) => transport,
+            Kind::Public { .. } => transport,
             // Flashbots Protect RPC fallback doesn't support buffered transport
             Kind::MEVBlocker { url, .. } => unbuffered_web3_client(url),
         };
@@ -104,7 +108,7 @@ impl Mempool {
 
     pub fn may_revert(&self) -> bool {
         match &self.config.kind {
-            Kind::Public(_) => true,
+            Kind::Public { .. } => true,
             Kind::MEVBlocker { .. } => false,
         }
     }

crates/driver/src/tests/setup/driver.rs

@@ -219,6 +219,7 @@ async fn create_config_file(
                     file,
                     r#"[[submission.mempool]]
                     mempool = "public"
+                    additional-tip-percentage = 0.0
                     "#,
                 )
                 .unwrap();

crates/driver/src/tests/setup/solver.rs

@@ -380,7 +380,11 @@ impl Solver {
                     gas_price_cap: eth::U256::MAX,
                     target_confirm_time: Default::default(),
                     retry_interval: Default::default(),
-                    kind: infra::mempool::Kind::Public(infra::mempool::RevertProtection::Disabled),
+                    kind: infra::mempool::Kind::Public {
+                        max_additional_tip: 0.into(),
+                        additional_tip_percentage: 0.,
+                        revert_protection: infra::mempool::RevertProtection::Disabled,
+                    },
                 }],
             )
             .await