Azure Iot Edge Module

IoT Edge Module Scaffolding

Prerequisites

Before scaffolding a module, gather the following information from the user:

1. Module name (PascalCase, e.g., "DataProcessorModule")
2. Module description (brief description of module purpose)

Scaffolding Process

Follow these steps in order to scaffold a new IoT Edge module:

Step 1: Detect or Load Project Structure

Run the project structure detection script to identify existing patterns:

python scripts/detect_project_structure.py --root .

Step 1.5: Verify IoTEdgeModules Folder Structure

If modules_base_path wasn't found or doesn't exist, ask the user via AskUserQuestion:

• Option 1: Create at default src/IoTEdgeModules/modules/
• Option 2: Specify custom path
• Option 3: Cancel scaffolding

Processing detection output:

1. Parse the JSON output
2. If config_source is "saved", use silently
3. If config_source is "detected", present findings and ask for confirmation via AskUserQuestion:
   • "Yes, use it" / "Save and use" / "No, customize"
4. If "Save and use": run python scripts/detect_project_structure.py --root . --save
5. If "No, customize" or detection fails, prompt for: project namespace, container registry URL, modules base path, contracts project name/path

Step 2: Gather Module-Specific Information

Ask the user for:

Required:

1. Module name (PascalCase)
2. Module description

Optional Features:

A. Private NuGet Feed

• Ask: "Does this project require a private NuGet feed? (Yes/No)"
• If Yes and not detected: Prompt for NuGet feed URL
• If Yes and detected: Confirm detected URL or allow override

B. Shared Contracts Project

• If contracts project was detected: Automatically use it for module constants (no prompt needed)
• If not detected: Ask "Do you have a shared contracts project? (Yes/No/Create standalone)"

Step 3: Validate and Normalize Module Names

Convert the user-provided module name to required formats:

ModuleName (PascalCase):

• Remove "Module" suffix if present, then add it back
• Example: "DataProcessor" → "DataProcessorModule"
• Example: "DataProcessorModule" → "DataProcessorModule"

modulename (lowercase):

• Convert ModuleName to lowercase
• Example: "DataProcessorModule" → "dataprocessormodule"

Confirm with user using AskUserQuestion tool:

Present the module details and ask for confirmation:

• Question: "Proceed with creating this module?"
• Header: "Confirm Module"
• Options:
  • "Yes, create module" → Continue to Step 4
  • "No, use different name" → Go back to Step 2 (gather module name)

Display in the question description:

Module will be created as:
• C# class name: <ModuleName>
• Module ID: <modulename>
• Directory: <modules_base_path>/<modulename>/

Do NOT assume "Yes" or proceed without using AskUserQuestion tool and getting explicit user confirmation

Step 4: Create Module Directory Structure

Create the module directory:

<modules_base_path>/<modulename>/

Check if directory already exists (MUST use this exact bash syntax):

test -d "<modules_base_path>/<modulename>" && echo "EXISTS" || echo "NOT_EXISTS"

Note: Do NOT use Windows CMD syntax like if exist. Always use Unix bash syntax as shown above.

• If EXISTS: Ask user "Module directory exists. Overwrite? (Yes/Rename/Cancel)"
• If Rename: Prompt for new name and restart from Step 3

Step 5: Generate Module Files from Templates

Use the template files in assets/ to generate module files with runtime substitutions. The skill generates 11 files total.

Placeholder substitutions:

Conditional placeholder handling:

A. Contracts Project Reference ({{CONTRACTS_PROJECT_REFERENCE}})

Calculate relative path from module directory to contracts directory:

Example:

• Module at: src/IoTEdgeModules/modules/mydemomodule/
• Contracts at: src/Company.IoT.Modules.Contracts/
• Relative path: ../../../Company.IoT.Modules.Contracts
  • Go up 3 levels: mydemomodule/ → modules/ → IoTEdgeModules/ → src/
  • Then down to: Company.IoT.Modules.Contracts/

If using shared contracts:

  <ItemGroup>
    <ProjectReference Include="<relative-path-to-contracts>/<contracts_project_name>.csproj" />
  </ItemGroup>

If NOT using shared contracts:

  <!-- No shared contracts project -->

B. Contracts Dockerfile COPY ({{CONTRACTS_CSPROJ_COPY}})

If using shared contracts:

COPY <contracts_project_path>/*.csproj ./src/

If NOT using shared contracts:

(empty - no COPY line)

C. NuGet Configuration ({{NUGET_CONFIG_SECTION}})

If using private NuGet feed:

ENV VSS_NUGET_EXTERNAL_FEED_ENDPOINTS="{\"endpointCredentials\": [{\"endpoint\":\"<nuget_feed_url>\", \"username\":\"docker\", \"password\":\"${FEED_ACCESSTOKEN}\"}]}"

If NOT using private NuGet feed:

(empty - no ENV line)

Template file mappings:

Processing workflow:

For each template file listed in the table above, process sequentially:

1. Read the template file from assets/
2. Replace all placeholders with calculated values
3. Write to target location in module directory using the target filename from the table
4. Report progress: "✓ Created "

Process all 11 files one at a time before proceeding to Step 6.

Step 6: Create Shared Contract Constants (Conditional)

If using shared contracts project:

Directory: <contracts_project_path>/<ModuleName>/

File: <ModuleName>Constants.cs

Process:

1. Create directory if it doesn't exist
2. Read template-ModuleConstants.cs
3. Replace placeholders
4. Write to contracts project location

If NOT using shared contracts:

Directory: <modules_base_path>/<modulename>/Contracts/

File: <ModuleName>Constants.cs

Process:

1. Create Contracts/ folder in module directory
2. Read template-ModuleConstants.cs
3. Replace {{PROJECT_NAMESPACE}}.Modules.Contracts with just {{ModuleName}}.Contracts
4. Write to module's Contracts folder

Step 6.5: Create LoggingBuilderExtensions (First Module Only)

This extension method is required for AddModuleConsoleLogging() in Program.cs.

If using shared contracts project:

Check if <contracts_project_path>/Extensions/LoggingBuilderExtensions.cs exists:

• If file exists: Skip this step (already created by previous module)
• If file does NOT exist: Create it

Directory: <contracts_project_path>/Extensions/

File: LoggingBuilderExtensions.cs

Process:

1. Create Extensions/ directory if it doesn't exist
2. Read template-LoggingBuilderExtensions.cs
3. Replace {{PROJECT_NAMESPACE}} placeholder
4. Write to contracts project Extensions folder
5. Report to user: "✓ Created LoggingBuilderExtensions.cs in shared contracts project"

If NOT using shared contracts:

Directory: <modules_base_path>/<modulename>/Extensions/

File: LoggingBuilderExtensions.cs

Process:

1. Create Extensions/ folder in module directory
2. Read template-LoggingBuilderExtensions.cs
3. Replace {{PROJECT_NAMESPACE}}.Modules.Contracts with {{ModuleName}}
4. Write to module's Extensions folder

Step 7: Scan and Select Deployment Manifests

Run the manifest scanning script:

python scripts/scan_manifests.py --root .

Process the output:

1. Parse JSON to get list of manifest files
2. If 0 manifests found: Go to Step 7.5 (create base manifest)
3. If 1 manifest found: Ask "Add module to ? (Yes/No)"
4. If multiple manifests found: Present selection list

Step 7.5: Handle "No Manifests Found" Scenario

If 0 manifests found, ask user to create a base manifest or skip:

• If Yes: Prompt for manifest name (default: "base"), create from assets/template-base.deployment.manifest.json at <manifests_base_path>/{name}.deployment.manifest.json, then add module via the update script
• If No: Skip to Step 9

Multi-manifest selection: If multiple manifests found, present list with module counts and let user pick which to update (comma-separated numbers, 'all', or 'none').

Step 8: Update Deployment Manifests (Automated)

For each selected manifest, run the update script:

python scripts/update_deployment_manifest.py \
  "<manifest_path>" \
  "<modulename>" \
  --registry "<container_registry>"

Process the output:

1. Check for "success": true in JSON output
2. Report to user: "✓ Added to (startup order: )"
3. If error: Report error and provide manual fallback instructions

If the script fails, show the error and provide manual fallback instructions from references/deployment-manifests.md.

Step 9: Update README.md (Optional)

Search for "Solution project overview" or "IoTEdge modules" section in README.md:

If section exists:

• Add entry: - **<modulename>** (\`) - `
• Insert alphabetically

If section doesn't exist:

• Ask user: "README.md section not found. Create it? (Yes/No)"

Step 9.5: Add Module to Solution File

Detect solution file:

Run the solution detection script:

python scripts/manage_solution.py --root . --detect

Process detection results:

If .slnx file found:

Automatically add module to solution:

python scripts/manage_solution.py \
  --root . \
  --add-module "<module_csproj_path>" \
  --module-name "<ModuleName>"

• Parse JSON output
• If action: "added": Report "✓ Added to solution at position "
• If action: "already_exists": Report "Module already in solution"
• If action: "error": Show error and continue

If .sln file found:

• Run manual instruction generator:

  python scripts/manage_solution.py \
    --root . \
    --add-module "<module_csproj_path>" \
    --module-name "<ModuleName>"
  

• Parse JSON output and display instructions field to user
• Recommend using: dotnet sln add "<module_csproj_path>"

If no solution file found:

• Skip this step
• Inform user: "No solution file found. Module created successfully without solution integration."

Step 10: Provide Summary and Next Steps

Summary of created files:

✓ Module scaffolding complete!

Created:
• Module directory: <module_full_path>/ (11 files)
• Constants file: <constants_full_path>
• LoggingBuilderExtensions: <"Created" or "Already exists - skipped">
• Updated manifests: <manifest_count> manifest(s) [or "Created base manifest" if first module]
• Solution integration: <"Added to .slnx" or "Manual instructions provided" or "Skipped">

Configuration:
• Container registry: <container_registry>
• Project namespace: <project_namespace>
• NuGet feed: <nuget_feed_url or "None">
• Shared contracts: <"Yes" or "No">

Next steps for the user:

1. Implement business logic in <ModuleName>Service.cs → ExecuteAsync()
2. Test locally: dotnet run --project <module_path> (uses mock IoT Hub client)
3. Build Docker image, push to registry, deploy manifest to IoT Hub

For post-scaffolding customizations (Quartz, config options, routing, direct methods, etc.), see references/customizations.md.

Reference Documentation

• references/module-structure.md - Module structure, naming conventions, and notes
• references/deployment-manifests.md - Deployment manifest configuration
• references/customizations.md - Post-scaffolding customizations, error handling, and config file format