Move v2_compat behind a Cargo feature.

This allows us to remove `gdc_rust_types` from the dependency tree if we
don't need it.

rust-connector-sdk/Cargo.toml

@@ -11,8 +11,11 @@ path = "src/lib.rs"
 name = "ndc_hub_example"
 path = "bin/main.rs"
 
+[features]
+v2_compat = ["dep:gdc_rust_types", "dep:indexmap"]
+
 [dependencies]
-gdc_rust_types = { git = "https://github.com/hasura/gdc_rust_types.git", rev = "3273434" }
+gdc_rust_types = { git = "https://github.com/hasura/gdc_rust_types.git", rev = "3273434", optional = true } # used for v2_compat
 ndc-client = { git = "http://github.com/hasura/ndc-spec.git", tag = "v0.1.0-rc.18" }
 ndc-test = { git = "http://github.com/hasura/ndc-spec.git", tag = "v0.1.0-rc.18" }
 
@@ -22,7 +25,7 @@ axum-extra = "^0.8.0"
 bytes = "1.5.0"
 clap = { version = "^4.4.7", features = ["derive", "env"] }
 http = "^0.2"
-indexmap = "2"
+indexmap = { version = "2", optional = true } # used for v2_compat
 mime = "0.3.17"
 opentelemetry = { version = "^0.20", default-features = false, features = ["rt-tokio", "trace"] }
 opentelemetry-http = "0.9.0"

rust-connector-sdk/src/default_main.rs

@@ -1,3 +1,4 @@
+#[cfg(feature = "v2_compat")]
 mod v2_compat;
 
 use std::error::Error;
@@ -180,11 +181,10 @@ where
         serve_command.service_token_secret.clone(),
     );
 
-    let router = if serve_command.enable_v2_compatibility {
+    #[cfg(feature = "v2_compat")]
+    let router = {
         let v2_router = create_v2_router(server_state, serve_command.service_token_secret.clone());
         Router::new().merge(router).nest("/v2", v2_router)
-    } else {
-        router
     };
 
     let port = serve_command.port;
@@ -326,6 +326,7 @@ where
         ))
 }
 
+#[cfg(feature = "v2_compat")]
 pub fn create_v2_router<C: Connector + 'static>(
     state: ServerState<C>,
     service_token_secret: Option<String>,