Mqtt5 shared subscription sample

.builder/actions/build_samples.py

@@ -27,6 +27,7 @@ def run(self, env):
             'samples/mqtt/custom_authorizer_connect',
             'samples/mqtt/cognito_connect',
             'samples/mqtt5/mqtt5_pubsub',
+            'samples/mqtt5/mqtt5_shared_subscription',
             "samples/pub_sub/basic_pub_sub",
             "samples/pub_sub/cycle_pub_sub",
             'samples/secure_tunneling/secure_tunnel',

.github/workflows/ci.yml

@@ -451,6 +451,9 @@ jobs:
       - name: run MQTT5 PubSub sample
         run: |
           python3 ${{ env.CI_UTILS_FOLDER }}/run_sample_ci.py --file ${{ env.CI_SAMPLES_CFG_FOLDER }}/ci_run_mqtt5_pubsub_cfg.json
+      - name: run MQTT5 Shared Subscription sample
+        run: |
+          python3 ${{ env.CI_UTILS_FOLDER }}/run_sample_ci.py --file ${{ env.CI_SAMPLES_CFG_FOLDER }}/ci_run_mqtt5_shared_subscription_cfg.json
       - name: configure AWS credentials (Cognito)
         uses: aws-actions/configure-aws-credentials@v1
         with:

.github/workflows/ci_run_mqtt5_shared_subscription_cfg.json

@@ -0,0 +1,26 @@
+{
+    "language": "CPP",
+    "sample_file": "./aws-iot-device-sdk-cpp-v2/build/samples/mqtt5/mqtt5_shared_subscription/mqtt5_shared_subscription",
+    "sample_region": "us-east-1",
+    "sample_main_class": "",
+    "arguments": [
+        {
+            "name": "--endpoint",
+            "secret": "ci/endpoint"
+        },
+        {
+            "name": "--cert",
+            "secret": "ci/mqtt5/us/mqtt5_thing/cert",
+            "filename": "tmp_certificate.pem"
+        },
+        {
+            "name": "--key",
+            "secret": "ci/mqtt5/us/mqtt5_thing/key",
+            "filename": "tmp_key.pem"
+        },
+        {
+            "name": "--is_ci",
+            "data": "true"
+        }
+    ]
+}

samples/CMakeLists.txt

@@ -16,6 +16,7 @@ add_subdirectory(mqtt/windows_cert_connect)
 add_subdirectory(mqtt/x509_credentials_provider_connect)
 add_subdirectory(mqtt/cognito_connect)
 add_subdirectory(mqtt5/mqtt5_pubsub)
+add_subdirectory(mqtt5/mqtt5_shared_subscription)
 add_subdirectory(pub_sub/basic_pub_sub)
 add_subdirectory(pub_sub/cycle_pub_sub)
 add_subdirectory(secure_tunneling/secure_tunnel)

samples/README.md

@@ -3,6 +3,7 @@
 * [Basic Pub-Sub](./pub_sub/basic_pub_sub/README.md)
 * [Basic Connect](./mqtt/basic_connect/README.md)
 * [Mqtt5 Pub-Sub](./mqtt5/mqtt5_pubsub/README.md)
+* [Mqtt5 Shared Subscription](./mqtt5/mqtt5_shared_subscription/README.md)
 * [Websocket Connect](./mqtt/websocket_connect/README.md)
 * [PKCS#11 Connect](./mqtt/pkcs11_connect/README.md)
 * [Raw Connect](./mqtt/raw_connect/README.md)

samples/mqtt5/mqtt5_shared_subscription/CMakeLists.txt

@@ -0,0 +1,25 @@
+cmake_minimum_required(VERSION 3.1)
+# note: cxx-17 requires cmake 3.8, cxx-20 requires cmake 3.12
+project(mqtt5_shared_subscription CXX)
+
+file(GLOB SRC_FILES
+       "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
+)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES})
+
+set_target_properties(${PROJECT_NAME} PROPERTIES
+    CXX_STANDARD 14)
+
+#set warnings
+if (MSVC)
+    target_compile_options(${PROJECT_NAME} PRIVATE /W4 /WX /wd4068)
+else ()
+    target_compile_options(${PROJECT_NAME} PRIVATE -Wall -Wno-long-long -pedantic -Werror)
+endif ()
+
+find_package(aws-crt-cpp REQUIRED)
+
+target_link_libraries(${PROJECT_NAME} AWS::aws-crt-cpp)

samples/mqtt5/mqtt5_shared_subscription/README.md

@@ -0,0 +1,96 @@
+# MQTT5 Shared Subscription
+
+[**Return to main sample list**](../../README.md)
+
+This sample uses the
+[Message Broker](https://docs.aws.amazon.com/iot/latest/developerguide/iot-message-broker.html)
+for AWS IoT to send and receive messages through an MQTT connection using MQTT5 using a Shared Subscription.
+
+MQTT5 introduces additional features and enhancements that improve the development experience with MQTT. You can read more about MQTT5 in the C++ V2 SDK by checking out the [MQTT5 user guide](../../../documents/MQTT5_Userguide.md).
+
+Note: MQTT5 support is currently in **developer preview**. We encourage feedback at all times, but feedback during the preview window is especially valuable in shaping the final product. During the preview period we may make backwards-incompatible changes to the public API, but in general, this is something we will try our best to avoid.
+
+Shared Subscriptions allow IoT devices to connect to a group where messages sent to a topic are then relayed to the group in a round-robin-like fashion. This is useful for distributing message load across multiple subscribing MQTT5 clients automatically. This is helpful for load balancing when you have many messages that need to processed.
+
+Shared Subscriptions rely on what is called a group identifier, which tells the MQTT5 broker/server which IoT devices are in what group. This is done when subscribing by formatting the subscription topic like the following: `$share/<group identifier>/<topic>`.
+* `$share`: Tells the MQTT5 broker/server that the device is subscribing to a Shared Subscription.
+* `<group identifier>`: Tells the MQTT5 broker/server which group to add this Shared Subscription to. THis is the group of MQTT5 clients that will be worked through as part of the round-robin when a message comes in. For example: `my-iot-group`.
+* `<topic>`: The topic that the Shared Subscription is for. Messages published to this topic will be processed in a round-robin fashion. For example, `test/topic`.
+
+As mentioned, Shared Subscriptions use a round-robbin like method of distributing messages. For example, say you have three MQTT5 clients all subscribed to the same Shared Subscription group and topic. If five messages are sent to the Shared Subscription topic, the messages will likely be delivered in the following order:
+* Message 1 -> Client one
+* Message 2 -> Client two
+* Message 3 -> Client three
+* Message 4 -> Client one
+* Message 5 -> Client two
+* etc...
+
+Your IoT Core Thing's [Policy](https://docs.aws.amazon.com/iot/latest/developerguide/iot-policies.html) must provide privileges for this sample to connect, subscribe, publish, and receive. Below is a sample policy that can be used on your IoT Core Thing that will allow this sample to run as intended.
+
+<details>
+<summary>(see sample policy)</summary>
+<pre>
+{
+  "Version": "2012-10-17",
+  "Statement": [
+    {
+      "Effect": "Allow",
+      "Action": [
+        "iot:Publish",
+        "iot:Receive"
+      ],
+      "Resource": [
+        "arn:aws:iot:<b>region</b>:<b>account</b>:topic/test/topic",
+        "arn:aws:iot:<b>region</b>:<b>account</b>:topic/$share/*/test/topic"
+      ]
+    },
+    {
+      "Effect": "Allow",
+      "Action": [
+        "iot:Subscribe"
+      ],
+      "Resource": [
+        "arn:aws:iot:<b>region</b>:<b>account</b>:topicfilter/test/topic",
+        "arn:aws:iot:<b>region</b>:<b>account</b>:topicfilter/$share/*/test/topic"
+      ]
+    },
+    {
+      "Effect": "Allow",
+      "Action": [
+        "iot:Connect"
+      ],
+      "Resource": [
+        "arn:aws:iot:<b>region</b>:<b>account</b>:client/test-*"
+      ]
+    }
+  ]
+}
+</pre>
+
+Replace with the following with the data from your AWS account:
+* `<region>`: The AWS IoT Core region where you created your AWS IoT Core thing you wish to use with this sample. For example `us-east-1`.
+* `<account>`: Your AWS IoT Core account ID. This is the set of numbers in the top right next to your AWS account name when using the AWS IoT Core website.
+
+Note that in a real application, you may want to avoid the use of wildcards in your ClientID or use them selectively. Please follow best practices when working with AWS on production applications using the SDK. Also, for the purposes of this sample, please make sure your policy allows a client ID of `test-*` to connect or use `--client_id <client ID here>` to send the client ID your policy supports.
+
+</details>
+
+## How to run
+
+To Run this sample using a direct MQTT connection with a key and certificate, use the following command:
+
+``` sh
+./mqtt5_shared_subscription  --endpoint <endpoint> --cert <path to the certificate> --key <path to the private key>
+```
+
+You can also pass a Certificate Authority file (CA) if your certificate and key combination requires it:
+
+``` sh
+./mqtt5_shared_subscription  --endpoint <endpoint> --cert <path to the certificate> --key <path to the private key> --ca_file <path to root CA>
+```
+
+Finally, you can also set the Shared Subscription group identifier and topic with `--group_identifier` and `--topic` respectively:
+
+``` sh
+./mqtt5_shared_subscription  --endpoint <endpoint> --cert <path to the certificate> --key <path to the private key> --group_identifier <group identifier> --topic <topic>
+```