ci: Make the mqtt example test to send only portion of the partition

This makes the test faster and more robust in very a busy WiFi environment
(our CI) and still exercises the scenario of fragmenting the message on
both mqtt and ssl levels (binary size to send > mqtt buffer size)

examples/protocols/mqtt/ssl/main/Kconfig.projbuild

@@ -17,4 +17,10 @@ menu "Example Configuration"
         bool
         default y if BROKER_CERTIFICATE_OVERRIDE != ""
 
+    config BROKER_BIN_SIZE_TO_SEND
+        # This option is not visible and is used only to set parameters for example tests
+        # Here we configure the data size to send and to be expected in the python script
+        int
+        default 20000
+
 endmenu

examples/protocols/mqtt/ssl/main/app_main.c

@@ -21,6 +21,7 @@
 #include "mqtt_client.h"
 #include "esp_tls.h"
 #include "esp_ota_ops.h"
+#include <sys/param.h>
 
 static const char *TAG = "MQTTS_EXAMPLE";
 
@@ -33,7 +34,7 @@ extern const uint8_t mqtt_eclipse_org_pem_start[]   asm("_binary_mqtt_eclipse_or
 extern const uint8_t mqtt_eclipse_org_pem_end[]   asm("_binary_mqtt_eclipse_org_pem_end");
 
 //
-// Note: this function is for testing purposes only publishing the entire active partition
+// Note: this function is for testing purposes only publishing part of the active partition
 //       (to be checked against the original binary)
 //
 static void send_binary(esp_mqtt_client_handle_t client)
@@ -42,7 +43,9 @@ static void send_binary(esp_mqtt_client_handle_t client)
     const void *binary_address;
     const esp_partition_t* partition = esp_ota_get_running_partition();
     esp_partition_mmap(partition, 0, partition->size, SPI_FLASH_MMAP_DATA, &binary_address, &out_handle);
-    int msg_id = esp_mqtt_client_publish(client, "/topic/binary", binary_address, partition->size, 0, 0);
+    // sending only the configured portion of the partition (if it's less than the partition size)
+    int binary_size = MIN(CONFIG_BROKER_BIN_SIZE_TO_SEND,partition->size);
+    int msg_id = esp_mqtt_client_publish(client, "/topic/binary", binary_address, binary_size, 0, 0);
     ESP_LOGI(TAG, "binary sent with msg_id=%d", msg_id);
 }
 

examples/protocols/mqtt/ssl/mqtt_ssl_example_test.py

@@ -36,20 +36,19 @@ def on_message(client, userdata, msg):
     global event_client_received_correct
     global event_client_received_binary
     if msg.topic == '/topic/binary':
-        binary = userdata
-        size = os.path.getsize(binary)
-        print('Receiving binary from esp and comparing with {}, size {}...'.format(binary, size))
+        binary, bin_size = userdata
+        print('Receiving binary from esp and comparing with {}, size {}...'.format(binary, bin_size))
         with open(binary, 'rb') as f:
             bin = f.read()
-            if bin == msg.payload[:size]:
+            if bin[:bin_size] == msg.payload[:bin_size]:
                 print('...matches!')
                 event_client_received_binary.set()
                 return
-            else:
-                recv_binary = binary + '.received'
-                with open(recv_binary, 'w') as fw:
-                    fw.write(msg.payload)
-                raise ValueError('Received binary (saved as: {}) does not match the original file: {}'.format(recv_binary, binary))
+            recv_binary = binary + '.received'
+            with open(recv_binary, 'w') as fw:
+                fw.write(msg.payload)
+            raise ValueError('Received binary (saved as: {}) does not match the original file: {}'.format(recv_binary, binary))
+
     payload = msg.payload.decode()
     if not event_client_received_correct.is_set() and payload == 'data':
         client.subscribe('/topic/binary')
@@ -64,7 +63,7 @@ def test_examples_protocol_mqtt_ssl(env, extra_data):
     broker_url = ''
     broker_port = 0
     """
-    steps: |
+    steps:
       1. join AP and connects to ssl broker
       2. Test connects a client to the same broker
       3. Test evaluates python client received correct qos0 message
@@ -82,6 +81,7 @@ def test_examples_protocol_mqtt_ssl(env, extra_data):
         value = re.search(r'\:\/\/([^:]+)\:([0-9]+)', dut1.app.get_sdkconfig()['CONFIG_BROKER_URI'])
         broker_url = value.group(1)
         broker_port = int(value.group(2))
+        bin_size = min(int(dut1.app.get_sdkconfig()['CONFIG_BROKER_BIN_SIZE_TO_SEND']), bin_size)
     except Exception:
         print('ENV_TEST_FAILURE: Cannot find broker url in sdkconfig')
         raise
@@ -91,7 +91,7 @@ def test_examples_protocol_mqtt_ssl(env, extra_data):
         client = mqtt.Client()
         client.on_connect = on_connect
         client.on_message = on_message
-        client.user_data_set(binary_file)
+        client.user_data_set((binary_file, bin_size))
         client.tls_set(None,
                        None,
                        None, cert_reqs=ssl.CERT_NONE, tls_version=ssl.PROTOCOL_TLSv1_2, ciphers=None)