Name	Name	Last commit message	Last commit date
parent directory ..
c	c
dotnet	dotnet
python	python
ts	ts
README.md	README.md

👉 Telemetry (Fan-in)

This scenario shows how multiple clients send data (the producers) to different topics that can be consumed by a single application (the consumer). This scenario also showcases routing the data to an Azure service.

Consider a use case where a backend solution needs to identify the location of vehicles on a map. Vehicles should be prohibited from listening to other vehicles location on their behalf. Finally, the location data need to be routed to a storage queue.

Client	Role	Operation	Topic/Topic Filter
vehicle01	producer	pub	vehicles/vehicle01/position
vehicle02	producer	pub	vehicles/vehicle02/position
map-app	consumer	sub	vehicles/+/position

Messages will use GeoJSON to represent the coordinates.

{
    "type": "Point",
    "coordinates": [125.6, 10.1]
}

🔒 Create Client Certificates

Run the following step commands to create the client certificates for vehicle01, vehicle02 and map-app clients.

# from folder scenarios/telemetry
step certificate create \
    vehicle01 vehicle01.pem vehicle01.key \
    --ca ~/.step/certs/intermediate_ca.crt \
    --ca-key ~/.step/secrets/intermediate_ca_key \
    --no-password --insecure \
    --not-after 2400h

step certificate create \
    vehicle02 vehicle02.pem vehicle02.key \
    --ca ~/.step/certs/intermediate_ca.crt \
    --ca-key ~/.step/secrets/intermediate_ca_key \
    --no-password --insecure \
    --not-after 2400h

step certificate create \
    map-app map-app.pem map-app.key \
    --ca ~/.step/certs/intermediate_ca.crt \
    --ca-key ~/.step/secrets/intermediate_ca_key \
    --no-password --insecure \
    --not-after 2400h

📐 Configure Event Grid Namespaces

Event Grid Namespaces requires to register the clients, and the topic spaces to set the client permissions.

Create the clients

The clients will be created based on the certificate subject, you can register the 3 clients in the portal or by running the script below:

# from folder scenarios/telemetry
source ../../az.env

az resource create --id "$res_id/clients/vehicle01" --properties '{
    "authenticationName": "vehicle01",
    "state": "Enabled",
    "clientCertificateAuthentication": {
        "validationScheme": "SubjectMatchesAuthenticationName"
    },
    "attributes": {
            "type": "vehicle"
    },
    "description": "This is a test publisher client"
}'

az resource create --id "$res_id/clients/vehicle02" --properties '{
    "authenticationName": "vehicle02",
    "state": "Enabled",
    "clientCertificateAuthentication": {
        "validationScheme": "SubjectMatchesAuthenticationName"
    },
    "attributes": {
            "type": "vehicle"
    },
    "description": "This is a test publisher client"
}'

az resource create --id "$res_id/clients/map-app" --properties '{
    "authenticationName": "map-app",
    "state": "Enabled",
    "clientCertificateAuthentication": {
        "validationScheme": "SubjectMatchesAuthenticationName"
    },
    "attributes": {
            "type": "map-client"
    },
    "description": "This is a test subscriber client"
}'

Configure topic spaces and permission bindings

# from folder scenarios/telemetry
az resource create --id "$res_id/topicSpaces/vehicles" --properties '{
    "topicTemplates": ["vehicles/#"]
}'

az resource create --id "$res_id/permissionBindings/vehiclesPub" --properties '{
    "clientGroupName":"$all",
    "topicSpaceName":"vehicles",
    "permission":"Publisher"
}'

az resource create --id "$res_id/permissionBindings/vehiclesSub" --properties '{
    "clientGroupName":"$all",
    "topicSpaceName":"vehicles",
    "permission":"Subscriber"
}'

Create the .env files with connection details

The required .env files can be configured manually, we provide the script below as a reference to create those files, as they are ignored from git.

# from folder scenarios/telemetry
source ../../az.env
host_name=$(az resource show --ids $res_id --query "properties.topicSpacesConfiguration.hostname" -o tsv)

echo "MQTT_HOST_NAME=$host_name" > vehicle01.env
echo "MQTT_USERNAME=vehicle01" >> vehicle01.env
echo "MQTT_CLIENT_ID=vehicle01" >> vehicle01.env
echo "MQTT_CERT_FILE=vehicle01.pem" >> vehicle01.env
echo "MQTT_KEY_FILE=vehicle01.key" >> vehicle01.env

echo "MQTT_HOST_NAME=$host_name" > vehicle02.env
echo "MQTT_USERNAME=vehicle02" >> vehicle02.env
echo "MQTT_CLIENT_ID=vehicle02" >> vehicle02.env
echo "MQTT_CERT_FILE=vehicle02.pem" >> vehicle02.env
echo "MQTT_KEY_FILE=vehicle02.key" >> vehicle02.env

echo "MQTT_HOST_NAME=$host_name" > map-app.env
echo "MQTT_USERNAME=map-app" >> map-app.env
echo "MQTT_CLIENT_ID=map-app" >> map-app.env
echo "MQTT_CERT_FILE=map-app.pem" >> map-app.env
echo "MQTT_KEY_FILE=map-app.key" >> map-app.env

🪰 Configure Mosquitto

To establish the TLS connection, the CA needs to be trusted, most MQTT clients allow to specify the ca trust chain as part of the connection, to create a chain file with the root and the intermediate use:

# from folder _mosquitto
cat ~/.step/certs/root_ca.crt ~/.step/certs/intermediate_ca.crt > chain.pem
cp chain.pem ../scenarios/telemetry

The chain.pem is used by mosquitto via the cafile settings to authenticate X509 client connections.

# from folder scenarios/telemetry
echo "MQTT_HOST_NAME=localhost" > vehicle01.env
echo "MQTT_CLIENT_ID=vehicle01" >> vehicle01.env
echo "MQTT_CERT_FILE=vehicle01.pem" >> vehicle01.env
echo "MQTT_KEY_FILE=vehicle01.key" >> vehicle01.env
echo "MQTT_CA_FILE=chain.pem" >> vehicle01.env

echo "MQTT_HOST_NAME=localhost" > vehicle02.env
echo "MQTT_CLIENT_ID=vehicle02" >> vehicle02.env
echo "MQTT_CERT_FILE=vehicle02.pem" >> vehicle02.env
echo "MQTT_KEY_FILE=vehicle02.key" >> vehicle02.env
echo "MQTT_CA_FILE=chain.pem" >> vehicle02.env

echo "MQTT_HOST_NAME=localhost" > map-app.env
echo "MQTT_CLIENT_ID=map-app" >> map-app.env
echo "MQTT_CERT_FILE=map-app.pem" >> map-app.env
echo "MQTT_KEY_FILE=map-app.key" >> map-app.env
echo "MQTT_CA_FILE=chain.pem" >> map-app.env

To use mosquitto without certificates: change the port to 1883 and disable TLS

# from folder scenarios/telemetry
echo "MQTT_HOST_NAME=localhost" > vehicle01.env
echo "MQTT_CLIENT_ID=vehicle01" >> vehicle01.env
echo "MQTT_TCP_PORT=1883" >> vehicle01.env
echo "MQTT_USE_TLS=false" >> vehicle01.env

echo "MQTT_HOST_NAME=localhost" > vehicle02.env
echo "MQTT_CLIENT_ID=vehicle02" >> vehicle02.env
echo "MQTT_TCP_PORT=1883" >> vehicle02.env
echo "MQTT_USE_TLS=false" >> vehicle02.env

echo "MQTT_HOST_NAME=localhost" > map-app.env
echo "MQTT_CLIENT_ID=map-app" >> map-app.env
echo "MQTT_TCP_PORT=1883" >> map-app.env
echo "MQTT_USE_TLS=false" >> map-app.env

🎲 Run the Sample

All samples are designed to be executed from the root scenario folder.

dotnet

To build the dotnet sample run:

# from folder scenarios/telemetry
dotnet build dotnet/telemetry.sln

To run the dotnet sample execute each line below in a different shell/terminal.

# from folder scenarios/telemetry
 dotnet/telemetry_producer/bin/Debug/net7.0/telemetry_producer --envFile=vehicle01.env

 dotnet/telemetry_producer/bin/Debug/net7.0/telemetry_producer --envFile=vehicle02.env

 dotnet/telemetry_consumer/bin/Debug/net7.0/telemetry_consumer --envFile=map-app.env

C

To build the C sample, run from the root folder:

cmake --preset=telemetry
cmake --build --preset=telemetry

This will generate the produced binary in scenarios/telemetry/c/build

To run the C sample, execute each line below in a different shell/terminal.

# from folder scenarios/telemetry
c/build/telemetry_producer vehicle01.env

c/build/telemetry_producer vehicle02.env

c/build/telemetry_consumer map-app.env

For alternate building/running methods and more information, see the C documentation.

python

Install the paho client for python:

pip install paho-mqtt

Install internal sample package:

pip install ../../mqttclients/python

To run the python sample have the necessary environment files are in scenarios/telemetry folder.

Then execute each line below in a different shell/terminal.

# from folder scenarios/telemetry
python python/telemetry_producer.py --env-file="vehicle01.env"

# from folder scenarios/telemetry
python python/telemetry_producer.py --env-file="vehicle02.env"

# from folder scenarios/telemetry
python python/telemetry_consumer.py --env-file=map-app.env

TypeScript

To build the TypeScript sample run:

Note: The scenario should already be built from the initial npm i command at the root.

# from folder scenarios/telemetry
npm run build --prefix ./ts/telemetryProducer && npm run build --prefix ./ts/telemetryConsumer

To run the dotnet sample execute each line below in a different shell/terminal:

# from folder scenarios/telemetry
node ./ts/telemetryProducer/dist/index.js --env-file vehicle01.env

# from folder scenarios/telemetry
node ./ts/telemetryProducer/dist/index.js --env-file vehicle02.env

# from folder scenarios/telemetry
node ./ts/telemetryConsumer/dist/index.js --env-file map-app.env

To see detailed MQTT.js debug logging configure the DEBUG environment variable before running the sample.

export DEBUG=mqttjs* && node ...

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

telemetry

telemetry

README.md

👉 Telemetry (Fan-in)

🔒 Create Client Certificates

📐 Configure Event Grid Namespaces

Create the clients

Configure topic spaces and permission bindings

Create the .env files with connection details

🪰 Configure Mosquitto

🎲 Run the Sample

dotnet

C

python

TypeScript

Files

telemetry

Directory actions

More options

Directory actions

More options

Latest commit

History

telemetry

Folders and files

parent directory

README.md

👉 Telemetry (Fan-in)

🔒 Create Client Certificates

📐 Configure Event Grid Namespaces

Create the clients

Configure topic spaces and permission bindings

Create the .env files with connection details

🪰 Configure Mosquitto

🎲 Run the Sample

dotnet

C

python

TypeScript