Fix Linux extension exits 0 without writing status file on enable

proxy_agent_extension/src/common.rs

@@ -8,6 +8,7 @@ use crate::structs;
 use crate::structs::FormattedMessage;
 use crate::structs::HandlerEnvironment;
 use crate::structs::TopLevelStatus;
+#[cfg(windows)]
 use proxy_agent_shared::service;
 use proxy_agent_shared::{misc_helpers, telemetry};
 use std::fs;
@@ -167,7 +168,28 @@ pub fn get_current_seq_no(exe_path: &Path) -> String {
 }
 
 pub fn get_proxy_agent_service_path() -> PathBuf {
-    service::query_service_executable_path(constants::PROXY_AGENT_SERVICE_NAME)
+    #[cfg(windows)]
+    {
+        match service::query_service_executable_path(constants::PROXY_AGENT_SERVICE_NAME) {
+            Ok(path) => path,
+            Err(e) => {
+                logger::write(format!(
+                    "get_proxy_agent_service_path: query failed with error: {e}"
+                ));
+                PathBuf::new()
+            }
+        }
+    }
+    // On Linux the GPA binary is always installed at a well-known fixed path by the
+    // setup tool. Avoid querying `systemctl show --property=ExecStart` here: the
+    // systemd unit-file cache may not be hot right after install, causing
+    // ExecStart to come back empty, which previously triggered a false
+    // VersionMismatch and a spurious re-install on every enable invocation.
+    #[cfg(not(windows))]
+    {
+        PathBuf::from(proxy_agent_shared::linux::EXE_FOLDER_PATH)
+            .join(constants::PROXY_AGENT_SERVICE_NAME)
+    }
 }
 
 pub fn get_proxy_agent_exe_path() -> PathBuf {

proxy_agent_setup/src/running.rs

@@ -11,9 +11,17 @@ pub fn proxy_agent_running_folder(_service_name: &str) -> PathBuf {
     let path;
     #[cfg(windows)]
     {
-        path = match service::query_service_executable_path(_service_name).parent() {
-            Some(p) => p.to_path_buf(),
-            None => proxy_agent_parent_folder().join("Package"),
+        path = match service::query_service_executable_path(_service_name) {
+            Ok(exe_path) => match exe_path.parent() {
+                Some(p) => p.to_path_buf(),
+                None => proxy_agent_parent_folder().join("Package"),
+            },
+            Err(e) => {
+                logger::write(format!(
+                    "query_service_executable_path failed for {_service_name}: {e}"
+                ));
+                proxy_agent_parent_folder().join("Package")
+            }
         };
     }
     #[cfg(not(windows))]

proxy_agent_shared/src/service.rs

@@ -94,30 +94,23 @@ pub fn update_service(
     }
 }
 
-pub fn query_service_executable_path(service_name: &str) -> PathBuf {
+pub fn query_service_executable_path(service_name: &str) -> Result<PathBuf> {
     #[cfg(windows)]
     {
         match windows_service::query_service_config(service_name) {
             Ok(service_config) => {
                 logger_manager::write_info(format!("Service {service_name} successfully queried",));
-                service_config.executable_path.to_path_buf()
+                Ok(service_config.executable_path.to_path_buf())
             }
             Err(e) => {
                 logger_manager::write_info(format!("Service {service_name} query failed: {e}",));
-                eprintln!("Service {service_name} query failed: {e}");
-                PathBuf::new()
+                Err(e)
             }
         }
     }
     #[cfg(not(windows))]
     {
-        match linux_service::query_service_executable_path(service_name) {
-            Ok(path) => path,
-            Err(e) => {
-                eprintln!("Service {service_name} query failed: {e}");
-                PathBuf::new()
-            }
-        }
+        linux_service::query_service_executable_path(service_name)
     }
 }