In this journey, we capture the regulatory compliance logic for the Food Supplier Verification Program in a smart contract deployed on a business network.
This business network defines:
Participants:
Supplier Importer Retailer Regulator
Assets:
ProductListingContract
Transactions:
createProductListing transferListing checkProducts updateExemptedList
Initially, the supplier will transfer the food products to an importer who verifies whether the supplier, country, and food type all match with the correct identifiers. At port of entry, the supplier is checked against a list of known suppliers in a database (managed by the regulator). If the supplier is of type exempt, then the products are then transferred to the retailer. If the supplier is of type non-exempt, then the products are checked against a list of known food products in the database (managed by the regulator). If the food is exempt product then transfer it to the retailer. If the food is a non-exempt product, the importer must conduct a harms analysis (either independently, or using a third-party). The supplier provides the harms analysis report to the regulator. The regulator reviews compliance attestation and transfers the products to the retailer.
The createProductListing function is called when an createProductListing transaction is submitted. The logic allows a supplier to create a ProductListingContract asset.
The transferListing function is called when a transferListing transaction is submitted by the owner of ProductListingContract. It is submitted either by Supplier to transfer ProductListingContract to Importer or by Importer to transfer ProductListingContract to Retailer when the exempt check for the products is completed.
The checkProducts function is called when a checkProducts transaction is submitted by the Supplier to perform the exempt check for the products present in the ProductListingContract. The status of ProductListingContract contract will change to CHECKCOMPLETED if all all the products are exempted else the status will change to HAZARDANALYSISCHECKREQ. HAZARDANALYSISCHECKREQ means the Supplier needs to provide Hazard Analysis report for the products. After submitting the report Supplier performs the checkProducts transaction to complete the exempt check for the products.
The updateExemptedList function is called when a updateExemptedList transaction is submitted by the Regulator to update the list of exempted Orgs ids and Product ids.
- Hyperledger Fabric
- Hyperledger Composer
- Blockchain
- Containers
- Cloud
- Install Hyperledger Composer development tools
- Configure and start Hyperledger Fabric network
- Generate the Business Network Archive file
- Deploy the Business Network Archive using Composer Playground
- (Alternative method) Deploy the Business Network Archive on Hyperledger Composer running locally
- Docker - v1.13 or higher
- Docker Compose - v1.8 or higher
- Node.js & npm - node v6.2.0 - v6.10.0 (v7+ not supported); npm comes with your node installation.
- Git client - needed for clone commands
- git - 2.9.x
- Python - 2.7.x
- Installing Hyperledger Composer Development Tools
- Starting Hyperledger Fabric
- Generate the Business Network Archive (BNA)
- Deploy the Business Network Archive on Hyperledger Composer running locally
Note: You may need to run these commands in superuser sudo mode. sudo allows a permitted user to execute a command as the superuser or another user, as specified by the security policy.
- The
composer-clicontains all the command line operations for developing business networks. To installcomposer-clirun the following command:
npm install -g composer-cli@0.16.0
- The
generator-hyperledger-composeris a Yeoman plugin that creates bespoke (e.g. customized) applications for your business network. Yeoman is an open source client-side development stack, consisting of tools and frameworks intended to help developers build web applications. To installgenerator-hyperledger-composerrun the following command:
npm install -g generator-hyperledger-composer@0.16.0
- The
composer-rest-serveruses the Hyperledger Composer LoopBack Connector to connect to a business network, extract the models and then present a page containing the REST APIs that have been generated for the model. To installcomposer-rest-serverrun the following command:
npm install -g composer-rest-server@0.16.0
- When combining
Yeomanwith thegenerator-hyperledger-composercomponent, it can interpret business networks and generate applications based on them. To installYeomanrun the following command:
npm install -g yo@2.0.0
First download the docker files for Fabric in preparation for creating a Composer profile. Hyperledger Composer uses Connection Profiles to connect to a runtime. A Connection Profile is a JSON document that lives in the user's home directory (or may come from an environment variable) and is referenced by name when using the Composer APIs or the Command Line tools. Using connection profiles ensures that code and scripts are easily portable from one runtime instance to another.
Start the Fabric and create a Composer profile using the following commands:
./downloadFabric.sh
./startFabric.sh
./createPeerAdminCard.shNo need to do it now; however as an fyi - you can stop and tear down Fabric using:
./stopFabric.sh
./teardownFabric.sh
To check that the structure of the files is valid, you can now generate a Business Network Archive (BNA) file for your business network definition. The BNA file is the deployable unit -- a file that can be deployed to the Composer runtime for execution.
Use the following command to generate the network archive:
npm installYou should see the following output:
Creating Business Network Archive
Looking for package.json of Business Network Definition
Input directory: /Users/ishan/Documents/git-demo/BlockchainPublicRegulationFabric-Food
Found:
Description: Sample food supplier verification network
Name: food-supply
Identifier: food-supply@0.0.1
Written Business Network Definition Archive file to
Output file: ./dist/food-supply.bna
Command succeededThe composer archive create command has created a file called food-supply.bna in the dist folder.
You can test the business network definition against the embedded runtime that stores the state of 'the blockchain' in-memory in a Node.js process. From your project working directory, open the file test/foodTest.js and run the following command:
npm test
You should see the following output :
> food-supply@0.0.1 test /Users/ishan/Documents/git-demo/BlockchainPublicRegulationFabric-Food
> mocha --recursive
FoodSupply - Test
#FSVP
✓ Create Participants (185ms)
✓ Transfer ProductListing to Importer
✓ Exempt Check for ProductListing (41ms)
✓ Transfer ProductListing to Retailer (56ms)
4 passing (1s)
Please start the local Fabric using the instructions.
Now change directory to the dist folder containing food-supply.bna file and type:
cd dist
composer runtime install --card PeerAdmin@hlfv1 --businessNetworkName food-supply
composer network start --card PeerAdmin@hlfv1 --networkAdmin admin --networkAdminEnrollSecret adminpw --archiveFile food-supply.bna --file networkadmin.card
composer card import --file networkadmin.card
You can verify that the network has been deployed by typing:
composer network ping --card admin@food-supply
You should see the the output as follows:
The connection to the network was successfully tested: food-supply
version: 0.16.0
participant: org.hyperledger.composer.system.NetworkAdmin#admin
Command succeeded
To create the REST API we need to launch the composer-rest-server and tell it how to connect to our deployed business network.
Now launch the server by changing directory to the BlockchainPublicRegulationFabric-Food folder and type:
cd ..
composer-rest-serverAnswer the questions posed at startup. These allow the composer-rest-server to connect to Hyperledger Fabric and configure how the REST API is generated.
- Enter
admin@food-supplyas the card name. - Select
never use namespaceswhen asked whether to use namespaces in the generated API. - Select
Nowhen asked whether to secure the generated API. - Select
Yeswhen asked whether to enable event publication. - Select
Nowhen asked whether to enable TLS security.
Test REST API
If the composer-rest-server started successfully you should see these two lines are output:
Web server listening at: http://localhost:3000
Browse your REST API at http://localhost:3000/explorer
Open a web browser and navigate to http://localhost:3000/explorer
You should see the LoopBack API Explorer, allowing you to inspect and test the generated REST API. Follow the instructions to test Business Network Definition as mentioned above in the composer section.