Hyperledger Fabric’s Application Development Practices¶
Refer to Sample Project
Certain practices can help the developer create applications which are one click deployable on Zeeve. They are:-
For packaging your product to be automated by Zeeve, you will need to dockerize your project’s services by creating
FROM node:8.9.0 WORKDIR /balance-transfer COPY . . ENV PORT=4000 RUN npm install CMD node app
Make use of
network-config.yaml(connections profiles) and
org.yaml(if required) for all blockchain related configurations. At the time of deployment for a network, Zeeve creates these files and allows the developer to download them along with the other artifacts. You can consider this file to develop your applications. All other application configs should be part of the Docker image itself.
.envfile containing an array of domain prefixes corrosponding to Ingress resource definitions. The syntax should be of the form:
("<domain_prefix_1>:<ingress_resource_name_1>" "<domain_prefix_2>:<ingress_resource_name_2> ...")
docker-compose-build.yamlfile for creating images of all services that your application requires. This will help Zeeve create relevant images, push them to the container-registry and later use them.
Each service definition whose container image would be created needs to have an
imagekeyword, the associated value needs to same as that of image name (Deployment.contianers.spec.containers.image) in k8_application.yaml.template.
version: "2.0" services: balance-transfer: build: context: . dockerfile: Dockerfile image: balance-transfer:latest container_name: balance-transfer-default ports: - '4000:4000' command: | bash -c "PORT=4000 node app" restart: always
Create a yaml file
k8_application.yaml.templateand keep it at your project’s root folder. The file needs to keep the following points in account:-
The image name for containers needs to adhere to the guideline outlined in the step above.
imagePullSecretsnamed container-registry-cred. Creation and updation of this secret is handled by Zeeve, but the definition is developers responsibility.
For mounting relevant crypto data and channel artifacts in a deployment, Zeeve will create secrets and mount them on
/crypto-datapath. The deployment/s on which this mounting takes place is identified by special character string
Host for each Ingress resource will be an amalgamation of information specified in .env file and domain assigned to your Kubernetes cluster.
Take special care to mount relevant persistent volumes as pods will be recreated whenever there is an application update.
apiVersion: v1 kind: Service metadata: name: balance-transfer-svc spec: type: ClusterIP ports: - port: 4000 targetPort: 4000 protocol: TCP selector: name: balance-transfer-dep --- apiVersion: apps/v1 kind: Deployment metadata: name: balance-transfer-dep spec: replicas: 1 selector: matchLabels: name: balance-transfer template: metadata: labels: name: balance-transfer spec: volumes: #- name: balance-transfer-data # persistentVolumeClaim: # claimName: balance-transfer-data-pvc @@replace_my_crypto_artifacts@@ imagePullSecrets: - name: container-registry-cred containers: - name: balance-transfer image: balance-transfer:12 imagePullPolicy: Always ports: - containerPort: 4000 protocol: TCP #livenessProbe: # httpGet: # path: / # port: 4000 command: - bash - -c - | echo "installing GO" cd /usr/local curl -O https://dl.google.com/go/go1.10.3.linux-amd64.tar.gz tar -xvf go1.10.3.linux-amd64.tar.gz echo "export PATH=$PATH:/usr/local/go/bin" >> /root/.bashrc source /root/.bashrc echo "configuring application" mkdir /application cd /application cp -r /balance-transfer/* ./ cp -Lr /crypto-data/* ./artifacts/ #npm install node app volumeMounts: #- mountPath: /application # name: balance-transfer-data @@replace_my_crypto_artifacts@@ --- kind: PersistentVolumeClaim apiVersion: v1 metadata: name: balance-transfer-data-pvc spec: accessModes: - "ReadWriteOnce" resources: requests: storage: "5Gi" --- apiVersion: extensions/v1beta1 kind: Ingress metadata: name: balance-transfer-ingress annotations: kubernetes.io/ingress.class: nginx nginx.ingress.kubernetes.io/backend-protocol: "http" spec: rules: - host: http: paths: - backend: serviceName: balance-transfer-svc servicePort: 4000
While uploading the project attach some supporting documents to explain the organisation names and other details that shall be put while creating networks for the product. These documents will help users to create and deploy networks and products on their own.