feat: add new endpoint for environment variables in the designer module (#791)

Author: halajohn

core/src/ten_manager/src/designer/env_var/mod.rs

@@ -0,0 +1,40 @@
+//
+// Copyright © 2025 Agora
+// This file is part of TEN Framework, an open source project.
+// Licensed under the Apache License, Version 2.0, with certain conditions.
+// Refer to the "LICENSE" file in the root directory for more information.
+//
+use std::env;
+use std::sync::Arc;
+
+use actix_web::{web, HttpResponse, Responder};
+use serde::{Deserialize, Serialize};
+
+use crate::designer::DesignerState;
+
+#[derive(Debug, Deserialize, Serialize)]
+pub struct GetEnvVarRequestPayload {
+    pub name: String,
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+pub struct GetEnvVarResponseData {
+    pub value: Option<String>,
+}
+
+/// This function handles requests for getting environment variables.
+/// It accepts a JSON payload with a "name" property and returns the
+/// corresponding environment variable value, or None if not defined.
+pub async fn get_env_var_endpoint(
+    request_payload: web::Json<GetEnvVarRequestPayload>,
+    _state: web::Data<Arc<DesignerState>>,
+) -> Result<impl Responder, actix_web::Error> {
+    let name = &request_payload.name;
+
+    // Cross-platform way to get environment variables.
+    let value = env::var(name).ok();
+
+    let response_data = GetEnvVarResponseData { value };
+
+    Ok(HttpResponse::Ok().json(response_data))
+}

core/src/ten_manager/src/designer/mod.rs

@@ -10,6 +10,7 @@ pub mod common;
 pub mod dir_list;
 pub mod doc_link;
 pub mod env;
+pub mod env_var;
 pub mod exec;
 pub mod extensions;
 pub mod file_content;
@@ -123,6 +124,7 @@ pub fn configure_routes(
             // Registry endpoints.
             .service(web::resource("/registry/packages").route(web::get().to(registry::packages::get_packages_endpoint)))
             // Environment endpoints.
-            .service(web::resource("/env").route(web::get().to(env::get_env_endpoint))),
+            .service(web::resource("/env").route(web::get().to(env::get_env_endpoint)))
+            .service(web::resource("/env-var").route(web::post().to(env_var::get_env_var_endpoint))),
     );
 }

core/src/ten_manager/tests/test_case/env_var/mod.rs

@@ -0,0 +1,123 @@
+//
+// Copyright © 2025 Agora
+// This file is part of TEN Framework, an open source project.
+// Licensed under the Apache License, Version 2.0, with certain conditions.
+// Refer to the "LICENSE" file in the root directory for more information.
+//
+#[cfg(test)]
+mod tests {
+    use std::env;
+
+    use actix_web::{test, web, App};
+    use ten_manager::designer::env_var::{
+        get_env_var_endpoint, GetEnvVarRequestPayload, GetEnvVarResponseData,
+    };
+
+    use crate::test_case::common::designer_state::create_designer_state;
+
+    #[actix_web::test]
+    async fn test_get_existing_env_var() {
+        // Setup
+        const TEST_VAR_NAME: &str = "TEST_ENV_VAR_EXISTING";
+        const TEST_VAR_VALUE: &str = "test_value";
+
+        // Set the environment variable
+        env::set_var(TEST_VAR_NAME, TEST_VAR_VALUE);
+
+        // Create test app with the endpoint
+        let state = web::Data::new(create_designer_state());
+        let app = test::init_service(
+            App::new()
+                .app_data(state.clone())
+                .route("/env-var", web::post().to(get_env_var_endpoint)),
+        )
+        .await;
+
+        // Create test request
+        let req = test::TestRequest::post()
+            .uri("/env-var")
+            .set_json(&GetEnvVarRequestPayload {
+                name: TEST_VAR_NAME.to_string(),
+            })
+            .to_request();
+
+        // Send request and get response.
+        let resp: GetEnvVarResponseData =
+            test::call_and_read_body_json(&app, req).await;
+
+        // Clean up.
+        env::remove_var(TEST_VAR_NAME);
+
+        // Verify response.
+        assert_eq!(resp.value, Some(TEST_VAR_VALUE.to_string()));
+    }
+
+    #[actix_web::test]
+    async fn test_get_nonexistent_env_var() {
+        // Setup - using a variable name that is unlikely to exist.
+        const TEST_VAR_NAME: &str = "TEST_ENV_VAR_NONEXISTENT_12345";
+
+        // Make sure the variable doesn't exist.
+        env::remove_var(TEST_VAR_NAME);
+
+        // Create test app with the endpoint
+        let state = web::Data::new(create_designer_state());
+        let app = test::init_service(
+            App::new()
+                .app_data(state.clone())
+                .route("/env-var", web::post().to(get_env_var_endpoint)),
+        )
+        .await;
+
+        // Create test request.
+        let req = test::TestRequest::post()
+            .uri("/env-var")
+            .set_json(&GetEnvVarRequestPayload {
+                name: TEST_VAR_NAME.to_string(),
+            })
+            .to_request();
+
+        // Send request and get response.
+        let resp: GetEnvVarResponseData =
+            test::call_and_read_body_json(&app, req).await;
+
+        // Verify response.
+        assert_eq!(resp.value, None);
+    }
+
+    #[actix_web::test]
+    async fn test_get_empty_env_var() {
+        // Setup.
+        const TEST_VAR_NAME: &str = "TEST_ENV_VAR_EMPTY";
+
+        // Set the environment variable to an empty string.
+        env::set_var(TEST_VAR_NAME, "");
+
+        // Create test app with the endpoint.
+        let state = web::Data::new(create_designer_state());
+        let app = test::init_service(
+            App::new()
+                .app_data(state.clone())
+                .route("/env-var", web::post().to(get_env_var_endpoint)),
+        )
+        .await;
+
+        // Create test request.
+        let req = test::TestRequest::post()
+            .uri("/env-var")
+            .set_json(&GetEnvVarRequestPayload {
+                name: TEST_VAR_NAME.to_string(),
+            })
+            .to_request();
+
+        // Send request and get response.
+        let resp: GetEnvVarResponseData =
+            test::call_and_read_body_json(&app, req).await;
+
+        // Clean up.
+        env::remove_var(TEST_VAR_NAME);
+
+        // Verify response - an empty string is still a value, not None.
+        assert_eq!(resp.value, Some("".to_string()));
+    }
+}

core/src/ten_manager/tests/test_case/mod.rs

@@ -7,6 +7,7 @@
 mod cmd;
 mod common;
 mod designer;
+mod env_var;
 mod fs;
 mod graph;
 mod log;