From 252443a50dc48939eb08b3bcd67273bb71bbe349 Mon Sep 17 00:00:00 2001
From: Sanchith Hegde <22217505+SanchithHegde@users.noreply.github.com>
Date: Fri, 5 Jan 2024 17:32:36 +0530
Subject: [PATCH] feat: include version number in response headers and on
 application startup (#3045)

---
 crates/drainer/src/main.rs         |  3 +++
 crates/router/Cargo.toml           |  2 +-
 crates/router/src/bin/router.rs    |  3 +++
 crates/router/src/bin/scheduler.rs |  8 ++++++--
 crates/router/src/middleware.rs    |  8 +++++++-
 crates/router_env/src/env.rs       | 10 ++++++++++
 6 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/crates/drainer/src/main.rs b/crates/drainer/src/main.rs
index 2b4142abc0..9e8b8e275c 100644
--- a/crates/drainer/src/main.rs
+++ b/crates/drainer/src/main.rs
@@ -20,6 +20,9 @@ async fn main() -> DrainerResult<()> {
     let shutdown_intervals = conf.drainer.shutdown_interval;
     let loop_interval = conf.drainer.loop_interval;
 
+    #[cfg(feature = "vergen")]
+    println!("Starting drainer (Version: {})", router_env::git_tag!());
+
     let _guard = router_env::setup(
         &conf.log,
         router_env::service_name!(),
diff --git a/crates/router/Cargo.toml b/crates/router/Cargo.toml
index a1ddc37bbf..eb7fbc7ddb 100644
--- a/crates/router/Cargo.toml
+++ b/crates/router/Cargo.toml
@@ -16,7 +16,7 @@ email = ["external_services/email", "dep:aws-config", "olap"]
 frm = []
 basilisk = ["kms"]
 stripe = ["dep:serde_qs"]
-release = ["kms", "stripe", "basilisk", "s3", "email", "backwards_compatibility", "business_profile_routing", "accounts_cache", "kv_store", "connector_choice_mca_id", "profile_specific_fallback_routing"]
+release = ["kms", "stripe", "basilisk", "s3", "email", "backwards_compatibility", "business_profile_routing", "accounts_cache", "kv_store", "connector_choice_mca_id", "profile_specific_fallback_routing", "vergen"]
 olap = ["data_models/olap", "storage_impl/olap", "scheduler/olap", "dep:analytics"]
 oltp = ["storage_impl/oltp"]
 kv_store = ["scheduler/kv_store"]
diff --git a/crates/router/src/bin/router.rs b/crates/router/src/bin/router.rs
index beb2869f99..a02758d8ed 100644
--- a/crates/router/src/bin/router.rs
+++ b/crates/router/src/bin/router.rs
@@ -34,6 +34,9 @@ async fn main() -> ApplicationResult<()> {
     conf.validate()
         .expect("Failed to validate router configuration");
 
+    #[cfg(feature = "vergen")]
+    println!("Starting router (Version: {})", router_env::git_tag!());
+
     let _guard = router_env::setup(
         &conf.log,
         router_env::service_name!(),
diff --git a/crates/router/src/bin/scheduler.rs b/crates/router/src/bin/scheduler.rs
index 32e9cfc6ca..b800ecb897 100644
--- a/crates/router/src/bin/scheduler.rs
+++ b/crates/router/src/bin/scheduler.rs
@@ -22,8 +22,6 @@ use tokio::sync::{mpsc, oneshot};
 const SCHEDULER_FLOW: &str = "SCHEDULER_FLOW";
 #[tokio::main]
 async fn main() -> CustomResult<(), ProcessTrackerError> {
-    // console_subscriber::init();
-
     let cmd_line = <CmdLineConf as clap::Parser>::parse();
 
     #[allow(clippy::expect_used)]
@@ -58,6 +56,12 @@ async fn main() -> CustomResult<(), ProcessTrackerError> {
     let scheduler_flow = scheduler::SchedulerFlow::from_str(&scheduler_flow_str)
         .expect("Unable to parse SchedulerFlow from environment variable");
 
+    #[cfg(feature = "vergen")]
+    println!(
+        "Starting {scheduler_flow} (Version: {})",
+        router_env::git_tag!()
+    );
+
     let _guard = router_env::setup(
         &state.conf.log,
         &scheduler_flow_str,
diff --git a/crates/router/src/middleware.rs b/crates/router/src/middleware.rs
index 0f2c5bd2cb..c6c94d3a78 100644
--- a/crates/router/src/middleware.rs
+++ b/crates/router/src/middleware.rs
@@ -70,7 +70,13 @@ where
 pub fn default_response_headers() -> actix_web::middleware::DefaultHeaders {
     use actix_web::http::header;
 
-    actix_web::middleware::DefaultHeaders::new()
+    let default_headers_middleware = actix_web::middleware::DefaultHeaders::new();
+
+    #[cfg(feature = "vergen")]
+    let default_headers_middleware =
+        default_headers_middleware.add(("x-hyperswitch-version", router_env::git_tag!()));
+
+    default_headers_middleware
         // Max age of 1 year in seconds, equal to `60 * 60 * 24 * 365` seconds.
         .add((header::STRICT_TRANSPORT_SECURITY, "max-age=31536000"))
         .add((header::VIA, "HyperSwitch"))
diff --git a/crates/router_env/src/env.rs b/crates/router_env/src/env.rs
index e57c38e7e4..644f9b50a1 100644
--- a/crates/router_env/src/env.rs
+++ b/crates/router_env/src/env.rs
@@ -167,3 +167,13 @@ macro_rules! profile {
         env!("CARGO_PROFILE")
     };
 }
+
+/// The latest git tag. If tags are not present in the repository, the short commit hash is used
+/// instead. Refer to the [`git describe`](https://git-scm.com/docs/git-describe) documentation for
+/// more details.
+#[macro_export]
+macro_rules! git_tag {
+    () => {
+        env!("VERGEN_GIT_DESCRIBE")
+    };
+}