Distributed REALTOR Engagement Tracking on Hyperledger Fabric

There is a simple AngularJS frontend application, a NodeJS backend application and of course a blockchain network. Locally, the app starts up a blockchain network using Docker containers; on Bluemix you can use the Blockchain service.

The Application uses Hyperledger Fabric v0.6.1-developer-preview and HFC 0.6.5.

This Application is based off IBM Hyperledger Boiler Plate guide.

• Go
• Govend Once you have installed go, you can download the package with go get -u github.com/govend/govend. Important: Be sure your GOPATH variable is defined, the directory exists, you have the right permissions to read/write in it and the installation (command above) completes correctly (empty output in console). Furthermore, to be able to use govend bin to download the vendor directory, you need to add your GOPATH/bin to the global PATH variable. For instance, add them to .bash_profile or .profile (e.g.):

export GOPATH=/whatever/directory/you/want
# e.g. /home/john/gopath  or  /Users/John/mygopath
export PATH=$PATH:$GOPATH/bin

Important: Remember to restart any instance of terminal running in order to apply the changes.

You can test the installation running the following command (once you cloned the project): npm run installgo

Please pay attention to this step or you will not be able to build your chaincode.

• NodeJS
• Docker
• Nodemon

Once you have installed node and npm, you can install the module with: npm install nodemon -g

Use git clone from your preferred workspace folder to clone your project-code with:

1. git clone https://github.com/NationalAssociationOfRealtors/EngagementOnChain.git
2. cd EngagementOnChain and run npm install

1. Pull peer image: docker pull hyperledger/fabric-peer:x86_64-0.6.1-preview
2. Pull membersrvc image: docker pull hyperledger/fabric-membersrvc:x86_64-0.6.1-preview
3. Pull fabric-baseimage image: docker pull hyperledger/fabric-baseimage:x86_64-0.2.1 (note: be sure you do not have already an image with the same tag, in that case, rename/tag first the current hyperledger/fabric-baseimage to something else)
4. Change tag to the fabric-baseimage:xx to latest: docker tag hyperledger/fabric-baseimage:x86_64-0.2.1 hyperledger/fabric-baseimage:latest This will prepare a docker baseimage in which the chaincode will be launched and deployed.

Important: Be sure after all the above procedure you have the following docker images (with correct commit code) in docker images:

hyperledger/fabric-baseimage    latest                 930520b2a511
hyperledger/fabric-baseimage    x86_64-0.2.1           930520b2a511
hyperledger/fabric-membersrvc   x86_64-0.6.1-preview   b3654d32e4f9
hyperledger/fabric-peer         x86_64-0.6.1-preview   21cb00fb27f4

From your WORKSPACE/EngagementOnChain folder:

docker-compose up

This will start up a local blockchain network with two validating peers and a memberservice. The first time you run this script it will take a little while to download the necessary images.

You can see if your local blockchain network is running by going to localhost:7050/chain in your browser. Once the network is up and running, open a second terminal and from your WORKSPACE/EngagementOnChain folder:

npm start

This will start up a NodeJS application that serves the frontend, deploys the chaincode to the network and will register the users with the memberservice. The application is configured to run with nodemon and node-sass to automatically restart the server when you make changes during development.

Check if the app is running at http://localhost:8080/ in your browser. You can login with the user credentials you find in testData/testData.json

To make local development easier there is a script that will cleanup your environment, start the blockchain network and run the app. From your WORKSPACE/fEngagementOnChain folder:

Warning: This script ask you either to clean or not your environment. Be aware answering yes you will permanently deleted all your containers (not images).

./start.sh

Once you have been thorugh the process of setting up the system and ensuring it runs correctly, you can routinely setup "demos" for interested parties by running:

./run_all.sh

This script will:

1. Cleanup the environment. You are prompted if you would like to do this.
2. Pull images
3. Clone the chaincode and prepare the code
4. Start the server

First run the following:

npm run build-css

This way node-sass will create the complete .css file composing all the .scss ones.

The SDK needs to register and enroll an admin user and any other users you would like to add. When this takes place the SDK receives enrollment certificates (ECerts) for each user. You only get these certificates once. So if you would redeploy or restart your app on Bluemix and the SDK wants to register and enroll the users again this would fail. Our solution to this problem is to register and enroll the users from your local environment before you deploy. When the ECerts are received, you can then push the app to Bluemix, including the ECerts. So the app that runs on Bluemix does not have to register and enroll the users again, because the ECerts are already available.

We managed to make all the procedure as much automatic as possible. Now you can upload your app and it will deploys on Bluemix and push all testData automatically with one command! (explained below)

Perform the following steps to run the application on Bluemix:

1. Create a Blockchain Service on Bluemix
2. Update the manifest.yml file (it is in the root of the project):
   • replace the name and host. The values can be anything, as long as they are unique
   • replace the name of the service. This should be the name of the Blockchain Service you just created
3. Copy the credentials of the Blockchain Service and overwrite the credentials in credentials.json in blockchain/deployBluemix. The suggestion is to get the credentials directly from the Bluemix Blockchain service dashboard. If you retrieve your Service Credentials from a console instance of Bluemix then you will need to edit your credentials.json. Add "credentials": { to line 2 and then add a closing } to the final line.
4. Download the TLS certificate; you can find the url at the bottom of the credentials.json
5. Rename the file to certificate.pem
6. Save the certificate in src/build-chaincode and blockchain/deployBluemix

Deployment and uploading procedure

The first and fundamental operation to do in the beginning is to register and enroll all the users, in order to collect all their private keys which are going to be used every time the application communicates with the Member Service. Therefore, we will procede with 2 separated steps:

1. Deployment of the chaincode (and it includes registering and enrolling all the users and adding all the data contained in testData.json)
2. Uploading of the app to your Bluemix space

1. Deployment

This will:

• Register and enroll users to the Bluemix MemberService. That means, WebAppAdmin user plus all the others listed in testData.json. It also saves the ECerts (private keys) in blockchain/deployBluemix/keyValStore-[SHORT_ID_YOUR_NETWORK].
• Send a deploy request to one of your Bluemix Peer. That means, deploying the chaincode and it also stores the chaincodeID in blockchain/deployBluemix/chaincode_id.
• Send an invoke request (with all the test data) to one of your Bluemix Peer. Run from the root folder of project:

npm run deploy

Then open the dashboard of the blockchain service on Bluemix. Wait until you see the chaincode id appear on the Network tab. Ensure that it is running on all four peers and that all the way at the end it says Up for x seconds/minutes. If this is the case, then your chaincode has been deployed successfully!

Note: It can take 2-3 minutes.

IMPORTANT: Do not remove the keys once they are generated or it will be necessary to recreate the blockchain service, as the keys are unique and the membersrvc will not create again for the same user once he is in its list.

2. Uploading app

This will push the app to your Bluemix space.

IMPORTANT: Be sure your manifest.yml is configured correctly before executing the command below.

Note: If you only want to push a new version of the application, you have to be sure the chaincode_id file is inside blockchain/deployBluemix and it contains the correct id listed under your bluemix blockchain service.

To avoid the auto-deployment be sure blockchain/deployBluemix/chaincode_id exists (do not add it in your .cfignore!).

Viceversa - Remove blockchain/deployBluemix/chaincode_id if you want your application to deploy a new chaincode.

Run from the root folder of project:

npm run push

For assistance with the cloud foundry cli, visit the cloud foundry repo. There are prerequisites for using the cf cli, such as homebrew.

Debugging

After the app has been pushed to Bluemix you can view the logs with:

cf logs [NAME_OF_THE_APP] --recent

Where NAME_OF_THE_APP is the app name you provided in the manifest.yml file

To check if your chaincode compiles before you deploy it, run npm run gobuild

T: I have troubles with registering and enrolling users / Login / Invoking and Querying / I get the following errore in console msg: 'Error:Failed to launch chaincode spec(Could not get deployment transaction for ... - LedgerError - ResourceNotFound: ledger: resource not found)' }

S: Check govend is installed correctly (Prerequisites, npm run installgo) and you have a vendor directory under src/build-chaincode. If everything is good with your vendors, try to run npm run gobuild and see if you are able to build your chaincode, to be sure there are no errors in your code. If any of these steps help, search for a similar error in the issues section and open eventually a new one.

T: I am using a Windows machine and I have troubles running npm install / node-gyp .

T: I can build the chaincode in local with go build or npm run gobuild; the server logs state my chaincode was successfully deployed and it returns a chaincode id; the app is up and running and I can browse the login page. Nevertheless:

I cannot login / During the deployment phase I have the following log from one of my peers:

Step 1 : FROM hyperledger/fabric-baseimage
Pulling repository docker.io/hyperledger/fabric-baseimage

********************
14:10:16.370 [dockercontroller] deployImage -> ERRO 01f Error building images: Tag latest not found in repository docker.io/hyperledger/fabric-baseimage
14:10:16.370 [dockercontroller] deployImage -> ERRO 020 Image Output:

or

Step 1 : FROM hyperledger/fabric-baseimage
---> 7cfcd874dfa0
Step 2 : COPY . $GOPATH/src/build-chaincode/
---> 756380302601
Removing intermediate container c656bb6a30db
Step 3 : WORKDIR $GOPATH
---> Running in a1bfaaf2fbb4
---> 35add88b3768
Removing intermediate container a1bfaaf2fbb4
Step 4 : RUN go install build-chaincode && cp src/build-chaincode/vendor/github.com/hyperledger/fabric/peer/core.yaml $GOPATH/bin && mv $GOPATH/bin/build-chaincode $GOPATH/bin/cde006ac528126c74bf3fb5467a8af93fb6f0254929bfb102911f40d77bbab11
---> Running in 1ebcca6f4c47
src/build-chaincode/utils/utils.go:5:2: cannot find package "github.com/hyperledger/fabric/core/chaincode/shim" in any of:
/opt/go/src/github.com/hyperledger/fabric/core/chaincode/shim (from $GOROOT)
/opt/gopath/src/github.com/hyperledger/fabric/core/chaincode/shim (from $GOPATH)
src/build-chaincode/utils/utils.go:8:2: cannot find package "github.com/pkg/errors" in any of:
/opt/go/src/github.com/pkg/errors (from $GOROOT)
/opt/gopath/src/github.com/pkg/errors (from $GOPATH)

The server logs something like:

error: [SDK] error on query: {"error":{"code":2,"metadata":{"_internal_repr":{}}},"msg":"Error: sql: no rows in result set"}
error:
{ error: { code: 2, metadata: { _internal_repr: {} } },
msg: 'Error: sql: no rows in result set' }
(node:25810) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 13): [object Object]

S: You are probably using a wrong version of the fabric-baseimage. Please go back to Setting up Hyperledger Fabric section and follow carefully all the steps.

T: I deployed the application on Bluemix, I can see the chaincode deployed correctly and the application running and accessible, nevertheless I cannot login.

S: That can be caused by a wrong deployment (due to a bad connection, for instance). Check into the logs of your application running on Bluemix if there is any meaningful error. Be sure you have under blockchain/deployBluemix/keyValStore-[SHORT_ID_YOUR_NETWORK] the keys for each user you try to login with. Check that into the logs of your chaincode container on the Bluemix service you have the complete output of the invoke request starting with: [invoke] INFO : -- Invoking function add_test_data with args.

A possible way to solve the issue is doing the following:

1. Remove the chaincode_id file
2. Deploy again
3. Push the application again (which will contain the updated chaincodeID)

If the problem persists, look first for similar discussions about that issue and eventually open a new one.

RAMCO

Dave Conroy

CRT Labs

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