Fix #1211 - adjust ESP32 example to serve FS

examples/esp32/Makefile

@@ -9,7 +9,7 @@ example: main/main.c Makefile
 COMPORT ?= /dev/cu.SLAB_USBtoUART
 ESPTOOL ?= esptool.py
 flash:
-	cd build && $(ESPTOOL) --chip esp32 -p $(COMPORT) -b 460800 --before=default_reset --after=hard_reset write_flash --flash_mode dio --flash_freq 40m --flash_size 2MB 0x8000 partition_table/partition-table.bin 0x1000 bootloader/bootloader.bin 0x10000 mongoose-esp32-example.bin
+	cd build && $(ESPTOOL) --chip esp32 -p $(COMPORT) -b 460800 --before=default_reset --after=hard_reset write_flash --flash_mode dio --flash_freq 40m --flash_size 2MB 0x8000 partition_table/partition-table.bin 0x1000 bootloader/bootloader.bin 0x100000 mongoose-esp32-example.bin
 
 clean:
 	rm -rf $(PROG) *.o *.dSYM *.gcov *.gcno *.gcda *.obj *.exe *.ilk *.pdb mongoose mongoose_* mongoose.* build sdkconfig

examples/esp32/main/CMakeLists.txt

@@ -2,3 +2,4 @@ idf_component_register(SRCS "main.c"
                             "wifi.c"
                             "../../../mongoose.c"
                        INCLUDE_DIRS "../../..")
+component_compile_options(-DMG_ENABLE_DIRECTORY_LISTING=1 -DMG_ENABLE_LINES)

examples/esp32/main/main.c

@@ -1,54 +1,53 @@
 // Copyright (c) 2020 Cesanta Software Limited
 // All rights reserved
 
+#include "esp_spiffs.h"
+#include "freertos/FreeRTOS.h"
 #include "mongoose.h"
 
 #define WIFI_SSID "WIFI_NETWORK"   // SET THIS!
 #define WIFI_PASS "WIFI_PASSWORD"  // SET THIS!
+#define FS_ROOT "/spiffs"
 
-#define SERVER_URL "http://0.0.0.0:80"
-#define CLIENT_URL "http://info.cern.ch"
-
-// Event handler for an server (accepted) connection
+// Event handler for an server (accepted) connection. Implemented endpoints:
+//    /api/stats  - return JSON object with ESP32 stats (free RAM)
+//    any other   - serve files from the filesystem
 static void cb(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   if (ev == MG_EV_HTTP_MSG) {
-    mg_http_reply(c, 200, "", "Hello from ESP!\n");
+    struct mg_http_message *hm = ev_data;
+    if (mg_http_match_uri(hm, "/api/stats")) {
+      mg_http_reply(c, 200, "", "{\"ram\": %lu}\n", xPortGetFreeHeapSize());
+    } else {
+      struct mg_http_serve_opts opts = {.root_dir = FS_ROOT};
+      mg_http_serve_dir(c, hm, &opts);
+    }
   }
 }
 
-// Event handler for a client connection - fetch the first web page in history
-// To enable TLS for HTTP,
-//   1. Copy "ca.pem" file to the ESP32 flash FS
-//   2. Add TLS init snippet for the connection, see examples/http-client
-static void cb2(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
-  if (ev == MG_EV_CONNECT) {
-    struct mg_str s = mg_url_host(CLIENT_URL);
-    mg_printf(c, "GET / HTTP/1.0\r\nHost: %.*s\r\n\r\n", (int) s.len, s.ptr);
-  } else if (ev == MG_EV_HTTP_MSG) {
-    struct mg_http_message *hm = ev_data;  // Print HTTP response
-    LOG(LL_INFO, ("Fetched:\n%.*s", (int) hm->message.len, hm->message.ptr));
-    c->is_closing = 1;
-  }
-}
-
-// Called after we're connected to WiFi network
-static void run_mongoose(void) {
-  struct mg_mgr mgr;
-  mg_log_set("3");
-  mg_mgr_init(&mgr);
-  mg_http_listen(&mgr, SERVER_URL, cb, &mgr);    // Listening server
-  mg_http_connect(&mgr, CLIENT_URL, cb2, &mgr);  // Example client
-  LOG(LL_INFO, ("Starting Mongoose web server v%s", MG_VERSION));
-  for (;;) mg_mgr_poll(&mgr, 1000);
-  mg_mgr_free(&mgr);
+// SPIFFS is flat, so tell Mongoose that the FS root is a directory
+// This cludge is not required for filesystems with directory support
+bool mg_is_dir(const char *path) {
+  return strcmp(path, FS_ROOT) == 0;
 }
 
 void app_main(void) {
+  // Mount filesystem
+  esp_vfs_spiffs_conf_t conf = {
+      .base_path = FS_ROOT, .max_files = 20, .format_if_mount_failed = true};
+  int res = esp_vfs_spiffs_register(&conf);
+  LOG(res == ESP_OK ? LL_INFO : LL_ERROR, ("FS %s, %d", conf.base_path, res));
+  mg_file_printf(FS_ROOT "/hello.txt", "%s", "hello from ESP");
+
   // Setup wifi. This function is implemented in wifi.c
   // It blocks until connected to the configured WiFi network
   void wifi_init(const char *ssid, const char *pass);
   wifi_init(WIFI_SSID, WIFI_PASS);
 
-  // Done connecting to WiFi, now start HTTP server
-  run_mongoose();
+  // Connected to WiFi, now start HTTP server
+  struct mg_mgr mgr;
+  mg_log_set("3");
+  mg_mgr_init(&mgr);
+  mg_http_listen(&mgr, "http://0.0.0.0:80", cb, &mgr);  // Listening server
+  LOG(LL_INFO, ("Starting Mongoose web server v%s", MG_VERSION));
+  for (;;) mg_mgr_poll(&mgr, 1000);  // Infinite event loop
 }

examples/esp32/partitions.csv

@@ -0,0 +1,5 @@
+# Name,   Type, SubType, Offset,  Size, Flags
+nvs,      data, nvs,     0x9000,  0x6000,
+phy_init, data, phy,     0xf000,  0x1000,
+storage,  data, spiffs,  0x10000, 0x10000,
+factory,  app,  factory, 0x100000, 1M,

examples/esp32/sdkconfig.defaults

@@ -0,0 +1,3 @@
+CONFIG_PARTITION_TABLE_CUSTOM=y
+CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions.csv"
+CONFIG_PARTITION_TABLE_FILENAME="partitions.csv"