samples: google_iot_device: Remove "command line" and replace with co…

…nfig.c (zephyrproject-rtos#8)

* samples: google_iot_device: Remove "command line" and replace with config.c

There is no "command line" in Zephyr RTOS. "Command line" which was
used previously is an artifact of a special-purpose, testing target
"native_posix", not portable to any other Zephyr target.

So, instead provide config.c file, where a user can define all needed
application parameters (which previously were passed on "command
line"). As such a file contain credentials, it should be never put
under version control. This commit includes a template file,
config.c.in, which can be copied by a user to config.c, and required
values filled in.

Signed-off-by: Paul Sokolovsky <[email protected]>

* samples: google_iot_device: README: Update for moving from cmdline to config.c

Signed-off-by: Paul Sokolovsky <[email protected]>

samples/net/google_iot_device/CMakeLists.txt

@@ -22,7 +22,7 @@ add_compile_definitions(IOTC_DISABLE_CERTVERIFY)
 
 target_sources(app PRIVATE
 	src/main.c
-	src/commandline.c
+	src/config.c
 	src/example_utils.c
 	src/bsp/iotc_bsp_tls_mbedtls.c
 	src/bsp/iotc_bsp_crypto_mbedtls.c

samples/net/google_iot_device/README.rst

@@ -90,16 +90,10 @@ in a Zephyr github repo clone in github/atigyi account
 - `west update`
 - `export ZEPHYR_TOOLCHAIN_VARIANT=zephyr`
 - `cd zephyr/samples/net/google_iot_device`
+- Copy template file `config.c.in` to `config.c`, and fill in Google Cloud
+  connection parameters (read comments there).
 - `west build -b native_posix -- -G'Unix Makefiles'`
-- provide an ECDSA private key in PEM format in the CWD in a file
-  named `ec_private.pem`. This private key is associated with the
-  Goolge IoT Device the sample app will impersonate.
-- `./build/zephyr/zephyr.exe -testargs -p [GOOGLE_CLOUD_PROJECT_ID] -d
-  [GOOGLE_CLOUD_DEVICE_PATH] -t [GOOGLE_CLOUD_PUBLIS_TOPIC]`
-- example command: `./build/zephyr/zephyr.exe -testargs -p
-  macr-o-matic-3100t -d
-  projects/macr-o-matic-3100t/locations/europe-west1/registries/garage-door-meters/devices/sz11-front-reel
-  -t /devices/sz11-front-reel/state`
+- Run the application: `./build/zephyr/zephyr.exe`
 
 See `Google Cloud MQTT Documentation
 <https://cloud.google.com/iot/docs/how-tos/mqtt-bridge>`_.

samples/net/google_iot_device/src/config.c.in

@@ -0,0 +1,24 @@
+/* Copyright 2019 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "config.h"
+
+/* CHANGE THIS */
+const char* iotc_project_id = "<GCP IoT Core Project ID>";
+/* CHANGE THIS */
+const char* iotc_device_path = "projects/<GCP IoT Core Project ID>/locations/<Region>/registries/<GCP IoT Core Registry ID>/devices/<GCP IoT Core Device ID>";
+/* CHANGE THIS */
+const char* iotc_publish_topic = "/devices/<GCP IoT Core Device ID>/state";
+/* CHANGE THIS*/
+const char* iotc_private_key_pem =
+"-----BEGIN EC PRIVATE KEY-----\n"
+"use\n"
+"your\n"
+"key\n"
+"-----END EC PRIVATE KEY-----\n";
+
+const char* iotc_publish_message = "Hello from Zephyr!";
+
+iotc_mqtt_qos_t iotc_example_qos = IOTC_MQTT_QOS_AT_LEAST_ONCE;

samples/net/google_iot_device/src/config.h

@@ -0,0 +1,18 @@
+/* Copyright 2019 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * Declarations for application config options.
+ */
+
+#include <iotc_mqtt.h>
+
+extern iotc_mqtt_qos_t iotc_example_qos;
+
+extern const char* iotc_project_id;
+extern const char* iotc_device_path;
+extern const char* iotc_private_key_pem;
+extern const char* iotc_publish_topic;
+extern const char* iotc_publish_message;

samples/net/google_iot_device/src/example_utils.c

@@ -7,7 +7,7 @@
 #include <iotc_jwt.h>
 #include <stdio.h>
 
-#include "commandline.h"
+#include "config.h"
 #include "example_utils.h"
 
 #define IOTC_UNUSED(x) (void)(x)
@@ -17,90 +17,6 @@ extern iotc_crypto_key_data_t iotc_connect_private_key_data;
 static iotc_timed_task_handle_t delayed_publish_task =
     IOTC_INVALID_TIMED_TASK_HANDLE;
 
-int iotc_example_handle_command_line_args(int argc, char* argv[]) {
-  char options[] = "h:p:d:t:m:f:";
-  int missingparameter = 0;
-  int retval = 0;
-
-  /* log the executable name and library version */
-  printf("\n%s\n%s\n", argv[0], iotc_cilent_version_str);
-
-  /* Parse the argv array for ONLY the options specified in the options string
-   */
-  retval = iotc_parse(argc, argv, options, sizeof(options));
-
-  if (-1 == retval) {
-    /* iotc_parse has returned an error, and has already logged the error
-       to the console. Therefore just silently exit here. */
-    return -1;
-  }
-
-  /* Check to see that the required parameters were all present on the command
-   * line */
-  if (NULL == iotc_project_id) {
-    missingparameter = 1;
-    printf("-p --project_id is required\n");
-  }
-
-  if (NULL == iotc_device_path) {
-    missingparameter = 1;
-    printf("-d --device_path is required\n");
-  }
-
-  if (NULL == iotc_publish_topic) {
-    missingparameter = 1;
-    printf("-t --publish_topic is required\n");
-  }
-
-  if (1 == missingparameter) {
-    /* Error has already been logged, above.  Silently exit here */
-    printf("\n");
-    return -1;
-  }
-
-  return 0;
-}
-
-int load_ec_private_key_pem_from_posix_fs(char* buf_ec_private_key_pem,
-                                          size_t buf_len) {
-  FILE* fp = fopen(iotc_private_key_filename, "rb");
-  if (fp == NULL) {
-    printf("ERROR!\n");
-    printf(
-        "\tMissing Private Key required for JWT signing.\n"
-        "\tPlease copy and paste your device's EC private key into\n"
-        "\ta file with the following path based on this executable's\n"
-        "\tcurrent working dir:\n\t\t\'%s\'\n\n"
-        "\tAlternatively use the --help command line parameter to learn\n"
-        "\thow to set a path to your file using command line arguments\n",
-        iotc_private_key_filename);
-    return -1;
-  }
-
-  fseek(fp, 0, SEEK_END);
-  long file_size = ftell(fp);
-  rewind(fp);
-
-  if ((size_t)file_size > buf_len) {
-    printf(
-        "private key file size of %lu bytes is larger that certificate buffer "
-        "size of %lu bytes\n",
-        file_size, (long)buf_len);
-    fclose(fp);
-    return -1;
-  }
-
-  long bytes_read = fread(buf_ec_private_key_pem, 1, file_size, fp);
-  fclose(fp);
-
-  if (bytes_read != file_size) {
-    printf("could not fully read private key file\n");
-    return -1;
-  }
-
-  return 0;
-}
-
 void on_connection_state_changed(iotc_context_handle_t in_context_handle,
                                  void* data, iotc_state_t state) {
   iotc_connection_data_t* conn_data = (iotc_connection_data_t*)data;

samples/net/google_iot_device/src/example_utils.h

@@ -7,20 +7,13 @@
 
 #include <iotc.h>
 
-/* Parses and manages commandline arguments. Project id, device path and publish
- * topic are require to be passed as command line arguments. Prints
- * notification if either of these is not found.
- */
-int iotc_example_handle_command_line_args(int argc, char* argv[]);
-
-/* Attempts to load the client's identifying private key from disk so that the
+/* Attempts to load the client's identifying private key so that the
    byte data may be passed to the 'iotc_connect function'.  Please note that the
    IoTC API and Board Support Package have various means to use private keys.
    This example assumes the use of one that must be provided to a TLS
    implementation in a buffer, but secure chips with slot-based key stores can
    also be used. Please see the Crypto BSP for more information. */
-int load_ec_private_key_pem_from_posix_fs(char* buf_ec_private_key_pem,
-                                          size_t buf_len);
+int load_ec_private_key_pem(char* buf_ec_private_key_pem, size_t buf_len);
 
 /* A callback function that will be invoked whenever the connection state
    has changed.
@@ -61,8 +54,8 @@ int load_ec_private_key_pem_from_posix_fs(char* buf_ec_private_key_pem,
 void on_connection_state_changed(iotc_context_handle_t in_context_handle,
                                  void* data, iotc_state_t state);
 
-/* A function that publishes to the topic that was specified in the command
-   line parameters of the application. This is invoked directly upon connect
+/* A function that publishes to the topic that was specified in the config
+   parameters of the application. This is invoked directly upon connect
    in the 'on_connection_state_changed' function, but also by the IoTC Client's
    event system on a 5 second interval. */
 void publish_function(iotc_context_handle_t context_handle,