[debug-endpoint]: add api for dumping config + git revision

Adding a /node-info route to collect data about the node_config and git_revision from a given node. NodeDebugService now takes in a reference to a NodeConfig as a parameter. Created a NodeInfo struct to contain the git_revision and node_config fields and make it easy to serialize the data using Serde macros. Also added dependencies to cargo.toml to support serde serialization and updated references to NodeDebugService in other files like in diem-node > src > lib.rs.

Closes: aptos-labs#9376

common/debug-interface/Cargo.toml

@@ -12,10 +12,13 @@ edition = "2018"
 [dependencies]
 anyhow = "1.0.38"
 bytes = "1.0.1"
-tokio = { version = "1.8.1", features = ["full"] }
 reqwest = { version = "0.11.2", features = ["blocking", "json"], default_features = false }
+serde = { version = "1.0.124", features = ["derive"], default-features = false }
+serde_json = "1.0.64"
+tokio = { version = "1.8.1", features = ["full"] }
 warp = "0.3.0"
 
+diem-config = { path = "../../config" }
 diem-logger = { path = "../logger" }
 diem-metrics = { path = "../metrics" }
 diem-workspace-hack = { path = "../workspace-hack" }

common/debug-interface/src/node_debug_service.rs

@@ -3,7 +3,10 @@
 
 //! Debug interface to access information in a specific node.
 
+use diem_config::config::NodeConfig;
 use diem_logger::{info, json_log, Filter, Logger};
+use diem_metrics::json_metrics::get_git_rev;
+use serde::{Deserialize, Serialize};
 use std::{net::SocketAddr, sync::Arc};
 use tokio::runtime::{Builder, Runtime};
 use warp::Filter as _;
@@ -13,8 +16,16 @@ pub struct NodeDebugService {
     runtime: Runtime,
 }
 
+#[derive(Clone, Debug, Default, Deserialize, PartialEq, Serialize)]
+struct NodeInfo {
+    #[serde(default)]
+    node_config: NodeConfig,
+    #[serde(default)]
+    git_revision: String,
+}
+
 impl NodeDebugService {
-    pub fn new(address: SocketAddr, logger: Option<Arc<Logger>>) -> Self {
+    pub fn new(address: SocketAddr, logger: Option<Arc<Logger>>, node_config: &NodeConfig) -> Self {
         let runtime = Builder::new_multi_thread()
             .thread_name("nodedebug")
             .enable_all()
@@ -65,7 +76,14 @@ impl NodeDebugService {
             .and(warp::path("log"))
             .and(local_filter.or(remote_filter));
 
-        let routes = log.or(warp::get().and(metrics.or(events)));
+        // Get /node-info (git revision the node was built at and the node config being used)
+        let node_info = NodeInfo {
+            git_revision: get_git_rev(),
+            node_config: node_config.clone(),
+        };
+        let node_info_route = warp::path("node-info").map(move || warp::reply::json(&node_info));
+
+        let routes = log.or(warp::get().and(metrics.or(events).or(node_info_route)));
 
         runtime
             .handle()

common/metrics/src/json_metrics.rs

@@ -14,3 +14,7 @@ fn add_revision_hash(mut json_metrics: HashMap<String, String>) -> HashMap<Strin
     json_metrics.insert("revision".to_string(), env!("GIT_REV").to_string());
     json_metrics
 }
+
+pub fn get_git_rev() -> String {
+    env!("GIT_REV").to_string()
+}

common/metrics/src/lib.rs

@@ -48,7 +48,7 @@
 #![recursion_limit = "128"]
 
 mod json_encoder;
-mod json_metrics;
+pub mod json_metrics;
 pub mod metric_server;
 mod public_metrics;
 

diem-node/src/lib.rs

@@ -215,7 +215,7 @@ fn setup_debug_interface(config: &NodeConfig, logger: Option<Arc<Logger>>) -> No
     .next()
     .unwrap();
 
-    NodeDebugService::new(addr, logger)
+    NodeDebugService::new(addr, logger, config)
 }
 
 async fn periodic_state_dump(node_config: NodeConfig, db: DbReaderWriter) {