v0.1.29 - fix auth routing: allow public GET /health operation bypass

.gitignore

@@ -4,5 +4,5 @@ nostr_core_lib/
 blobs/
 c-relay/
 text_graph/
-.test_keys/
+.test_keys
 ginxsom-local.service

deploy_local.sh

@@ -199,5 +199,5 @@ echo "  Reload:  sudo systemctl reload nginx"
 echo "  Logs:    sudo tail -f /var/log/nginx/error.log"
 echo ""
 echo "Test the server:"
-echo "  curl http://localhost:$NGINX_PORT/health"
-echo "  curl http://localhost:$NGINX_PORT/"
+echo "  curl -k https://localhost:$NGINX_PORT/health"
+echo "  curl -k https://localhost:$NGINX_PORT/"

plans/fix-ginxsom-cpu-spin.md

@@ -0,0 +1,149 @@
+# Fix: Ginxsom 100% CPU Busy-Wait Bug
+
+## Root Cause Analysis
+
+The ginxsom-fcgi process consumes 100% CPU due to a **busy-wait spin loop** in the relay management thread.
+
+### The Bug Chain
+
+1. **`relay_management_thread()`** in `src/relay_client.c:328` runs a `while` loop calling `nostr_relay_pool_poll()` with a 1000ms timeout
+2. **`nostr_relay_pool_poll()`** in `nostr_core_lib/nostr_core/core_relay_pool.c:1699` iterates over all relays, but **skips disconnected relays** at line 1725-1728 — it only calls `nostr_ws_receive()` (which actually blocks) for connected relays
+3. **When no relays are connected** (or all are in error/disconnected state), the entire poll function returns 0 instantly with zero blocking
+4. **The caller has no sleep** for the `events_processed == 0` case — it immediately loops back and calls poll again
+5. This creates a **tight spin loop** consuming 100% of a CPU core
+
+### Additional Issues Found
+
+- **No signal handling**: `main.c` has zero `signal()`, `SIGTERM`, or `SIGINT` handling. When systemd sends SIGTERM to stop the service, the process ignores it and must be SIGKILL'd after timeout (confirmed in journal: `State 'stop-sigterm' timed out. Killing.`)
+- **`relay_client_stop()` never called**: The cleanup function exists but is never invoked — there's no shutdown path
+- **`g_relay_state.running` not volatile**: The `running` flag is read by the management thread but set by the main thread (or signal handler). Without `volatile`, the compiler may optimize away the check
+
+```mermaid
+graph TD
+    A["relay_management_thread()"] -->|"while running"| B["nostr_relay_pool_poll(pool, 1000)"]
+    B --> C{"Any relays connected?"}
+    C -->|"Yes"| D["nostr_ws_receive() blocks up to timeout_ms"]
+    C -->|"No - all disconnected"| E["Returns 0 immediately"]
+    D --> F{"events_processed > 0?"}
+    E --> F
+    F -->|"> 0"| A
+    F -->|"== 0"| G["No sleep! Loops immediately"]
+    F -->|"< 0"| H["sleep(1) then loop"]
+    G -->|"BUSY WAIT"| A
+```
+
+## Fixes Required
+
+### Fix 1: Add idle sleep to poll loop (`src/relay_client.c`)
+
+**File:** `src/relay_client.c`, lines 327-337
+
+**Before:**
+```c
+while (g_relay_state.running) {
+    int events_processed = nostr_relay_pool_poll(g_relay_state.pool, 1000);
+    if (events_processed < 0) {
+        app_log(LOG_ERROR, "Error polling relay pool");
+        sleep(1);
+    }
+}
+```
+
+**After:**
+```c
+while (g_relay_state.running) {
+    int events_processed = nostr_relay_pool_poll(g_relay_state.pool, 1000);
+    if (events_processed < 0) {
+        app_log(LOG_ERROR, "Error polling relay pool");
+        sleep(1);
+    } else if (events_processed == 0) {
+        // Prevent busy-wait when no relays are connected or no events pending.
+        // nostr_relay_pool_poll() returns immediately if all relays are disconnected
+        // because it skips the blocking nostr_ws_receive() call for non-connected relays.
+        usleep(100000); // 100ms idle sleep
+    }
+}
+```
+
+### Fix 2: Make `running` flag volatile (`src/relay_client.c`)
+
+**File:** `src/relay_client.c`, line 39
+
+**Before:**
+```c
+static struct {
+    int enabled;
+    int initialized;
+    int running;
+    ...
+```
+
+**After:**
+```c
+static struct {
+    int enabled;
+    int initialized;
+    volatile int running;
+    ...
+```
+
+### Fix 3: Add signal handler for graceful shutdown (`src/main.c`)
+
+**File:** `src/main.c`
+
+Add near the top (after includes):
+```c
+#include <signal.h>
+
+static volatile sig_atomic_t g_shutdown_requested = 0;
+
+static void shutdown_handler(int signum) {
+    (void)signum;
+    g_shutdown_requested = 1;
+}
+```
+
+Register the handler before the FCGI loop (before line 2664):
+```c
+// Register signal handlers for graceful shutdown
+signal(SIGTERM, shutdown_handler);
+signal(SIGINT, shutdown_handler);
+```
+
+### Fix 4: Call `relay_client_stop()` on shutdown (`src/main.c`)
+
+**File:** `src/main.c`
+
+Modify the FCGI loop condition (line 2667) to also check the shutdown flag:
+```c
+while (FCGI_Accept() >= 0 && !g_shutdown_requested) {
+```
+
+Add cleanup after the FCGI loop exits (before `return 0` at line 3068):
+```c
+  // Graceful shutdown
+  app_log(LOG_INFO, "Shutting down ginxsom...");
+  relay_client_stop();
+  app_log(LOG_INFO, "Ginxsom shutdown complete");
+```
+
+Also add the `relay_client.h` include at the top of `main.c`.
+
+## Summary of Changes
+
+| File | Change | Purpose |
+|------|--------|---------|
+| `src/relay_client.c:328-336` | Add `usleep(100000)` when poll returns 0 | Fix 100% CPU busy-wait |
+| `src/relay_client.c:39` | Make `running` field `volatile` | Thread-safe flag checking |
+| `src/main.c` (top) | Add signal handler function | Respond to SIGTERM/SIGINT |
+| `src/main.c` (before FCGI loop) | Register signal handlers | Enable graceful shutdown |
+| `src/main.c:2667` | Add `&& !g_shutdown_requested` to loop | Exit FCGI loop on signal |
+| `src/main.c` (after FCGI loop) | Call `relay_client_stop()` | Clean up relay thread |
+
+## Testing
+
+1. Build locally: `make clean && make`
+2. Run locally and verify CPU usage stays near 0% when idle
+3. Send SIGTERM and verify clean shutdown (no SIGKILL needed)
+4. Deploy to remote server via `deploy_lt.sh`
+5. Monitor with `top` to confirm CPU usage is normal

src/ginxsom.h

@@ -10,8 +10,8 @@
 // Version information (auto-updated by build system)
 #define VERSION_MAJOR 0
 #define VERSION_MINOR 1
-#define VERSION_PATCH 28
-#define VERSION "v0.1.28"
+#define VERSION_PATCH 29
+#define VERSION "v0.1.29"
 
 #include <stddef.h>
 #include <stdint.h>

src/main.c

@@ -23,6 +23,15 @@
 #include <unistd.h>
 #include <dirent.h>
 #include <sched.h>
+#include <signal.h>
+
+// Shutdown flag set by signal handler - volatile sig_atomic_t is async-signal-safe
+static volatile sig_atomic_t g_shutdown_requested = 0;
+
+static void shutdown_handler(int signum) {
+    (void)signum;
+    g_shutdown_requested = 1;
+}
 
 // Centralized logging system (declaration in ginxsom.h)
 void app_log(log_level_t level, const char *format, ...) {
@@ -2663,8 +2672,12 @@ if (!config_loaded /* && !initialize_server_config() */) {
   /////////////////////////////////////////////////////////////////////
   app_log(LOG_INFO, "FastCGI request loop starting - ready to accept requests");
 
+  // Register signal handlers for graceful shutdown
+  signal(SIGTERM, shutdown_handler);
+  signal(SIGINT, shutdown_handler);
+
   int first_request = 1;
-  while (FCGI_Accept() >= 0) {
+  while (FCGI_Accept() >= 0 && !g_shutdown_requested) {
     // Test stderr capture on first request
     if (first_request) {
       fprintf(stderr, "FCGI: First request received - testing nginx stderr capture\n");
@@ -2794,6 +2807,8 @@ if (!config_loaded /* && !initialize_server_config() */) {
       operation = "list";
     } else if (strcmp(request_method, "GET") == 0 && strcmp(request_uri, "/auth") == 0) {
       operation = "challenge";
+    } else if (strcmp(request_method, "GET") == 0 && strcmp(request_uri, "/health") == 0) {
+      operation = "health";
     } else if (strcmp(request_method, "DELETE") == 0) {
       operation = "delete";
       resource_hash = extract_sha256_from_uri(request_uri);
@@ -2831,6 +2846,8 @@ if (!config_loaded /* && !initialize_server_config() */) {
         // HEAD requests might not require auth depending on config - let handler decide
       } else if (strcmp(operation, "list") == 0) {
         // List operation might be optional auth - let handler decide
+      } else if (strcmp(operation, "health") == 0) {
+        // Health endpoint is public and doesn't require authentication - let handler decide
       } else if (strcmp(operation, "admin") == 0 && strcmp(request_uri, "/api/health") == 0) {
         // Health endpoint is public and doesn't require authentication - let handler decide
       } else if (strcmp(operation, "admin_event") == 0) {
@@ -3065,6 +3082,11 @@ if (!config_loaded /* && !initialize_server_config() */) {
     }
   }
 
+  // Graceful shutdown - stop relay client thread cleanly
+  app_log(LOG_INFO, "Shutting down ginxsom (shutdown_requested=%d)...", (int)g_shutdown_requested);
+  relay_client_stop();
+  app_log(LOG_INFO, "Ginxsom shutdown complete");
+
   return 0;
 }
 // ===== END UNUSED CODE =====

src/relay_client.c

@@ -36,7 +36,7 @@ void app_log(log_level_t level, const char* format, ...);
 static struct {
     int enabled;
     int initialized;
-    int running;
+    volatile int running;
     char db_path[512];
     nostr_relay_pool_t* pool;
     char** relay_urls;
@@ -332,6 +332,11 @@ static void *relay_management_thread(void *arg) {
         if (events_processed < 0) {
             app_log(LOG_ERROR, "Error polling relay pool");
             sleep(1);
+        } else if (events_processed == 0) {
+            // Prevent busy-wait: nostr_relay_pool_poll() returns immediately when all
+            // relays are disconnected because it skips the blocking nostr_ws_receive()
+            // call for non-connected relays. Without this sleep, the loop spins at 100% CPU.
+            usleep(100000); // 100ms idle sleep
         }
         // Pool handles all connection management, reconnection, and message processing
     }