Setup basic HA features for the Peers

- Add a new label to each peer to mark which org it is in - Create new service per org, that matches this label - so the service can pick from one of multiple pods - Update the kubeproxy to give more choice of ha stratergies - Update the application configmaps and samples to refer to this new service rather than specific peers Signed-off-by: Matthew B White <[email protected]>
hyperledger · Nov 15, 2021 · 5f0da48 · 5f0da48
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diff --git a/test-network-k8s/docs/HIGH_AVAILABILITY.md b/test-network-k8s/docs/HIGH_AVAILABILITY.md
@@ -0,0 +1,71 @@
+# High Availability
+
+The peers have been configured so they implemented a essential failover/high-availability configuration.
+
+Two important notes:
+
+1. The word 'gateway' in the k8s definitions is being used in a generic way. It is not tied to the concept of the 'Fabric Gateway' component. However using the 'Fabric-Gateway' with the udpated SDKs, make connecting to Fabric even easier. There is a single connection, that can easily be handled with core k8s abilities. Attempting the approach described below with the older SDKs is not recommended.
+2. Long Lived gRPC connections. Remember that the connections between components in Fabric are long-lived gRPC connections. From a client application's perspective that means the connection will be load-balanced when initially connected, but unless the connection breaks, it will not be 're-load-balanced'. It's important to keep this in mind.
+
+## Peer Gateway Services
+
+Each peer has defined their own K8S service, with the selector specifically choosing only one peer pod. 
+In this test-network, there are two peers per organization. Using a service with a different selector that
+picks both peer pods, allows a degree of load balancing.
+
+```yaml
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: org2-peer-gateway-svc
+spec:
+  ports:
+    - name: gossip
+      port: 7051
+      protocol: TCP
+  selector:
+    org: org2
+```
+
+The selector is `org: org2` that is defined in the specification of the Peer's Deployment. 
+
+```yaml
+  template:
+    metadata:
+      labels:
+        app: org2-peer1
+        org: org2
+```
+
+## Kube Proxy Configuration
+The proxy configuration is set to be `ipvs`. This gives a lot more scope for different load balancing algorthms.
+"Round Robin" is the default configuration (as used in this test network). For more information check this [deep dive](https://kubernetes.io/blog/2018/07/09/ipvs-based-in-cluster-load-balancing-deep-dive) on the Kubernetes blog.
+
+For this KIND cluster, this is configured by updating the cluster configuration, add the following yaml.
+
+```yaml
+networking:
+  kubeProxyMode: "ipvs"
+```
+
+## Application and TLS Configuration
+
+It is important that applications connect to the `org2-peer-gateway-svc` or `org1-peer-gateway-svc` rather that specific peer services. That way the service can load balance.  However if TLS used, errors will occur as the host name that is connected to is different to that used by the application. 
+
+The solution is to add the additional servicename to the hosts field in the SAN section of the TLS certificate. As an example here is the command that is used to create the TLS certificate for org1-peer1.  Note the 
+
+```bash
+fabric-ca-client enroll --url https://org1-peer1:peerpw@org1-ecert-ca --csr.hosts org1-peer1,org1-peer-gateway-svc --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org1.example.com/peers/org1-peer1.org1.example.com/msp
+```
+
+## Summary
+
+The FabricGateway and updated SDKs, improve the connection from a client application to Fabric, by needing only a single connection to one peer. By using a K8S service fronting two or more peer pods, a degree of load-balancing can be achieved. Remember that this will only be load balanced when the connection is first created. If a single peer becomes heavily loaded, K8S will not move any existing connection. 
+
+To achieve this you would need to have a monitoring system that can trigger applications to disconnect and reconnect. 
+
+If the connection drops, the application can reconnect and will get to a working peer.
+
+
+
diff --git a/test-network-k8s/kube/org1/org1-peer1.yaml b/test-network-k8s/kube/org1/org1-peer1.yaml
@@ -43,6 +43,7 @@ spec:
     metadata:
       labels:
         app: org1-peer1
+        org: org1
     spec:
       containers:
         - name: main
@@ -100,4 +101,16 @@ spec:
       port: 9443
       protocol: TCP
   selector:
-    app: org1-peer1
+    app: org1-peer1
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: org1-peer-gateway-svc
+spec:
+  ports:
+    - name: gossip
+      port: 7051
+      protocol: TCP
+  selector:
+    org: org1
diff --git a/test-network-k8s/kube/org1/org1-peer2.yaml b/test-network-k8s/kube/org1/org1-peer2.yaml
@@ -43,6 +43,7 @@ spec:
     metadata:
       labels:
         app: org1-peer2
+        org: org1
     spec:
       containers:
         - name: main

diff --git a/test-network-k8s/kube/org2/org2-peer1.yaml b/test-network-k8s/kube/org2/org2-peer1.yaml
@@ -43,6 +43,7 @@ spec:
     metadata:
       labels:
         app: org2-peer1
+        org: org2
     spec:
       containers:
         - name: main
@@ -101,4 +102,16 @@ spec:
       port: 9443
       protocol: TCP
   selector:
-    app: org2-peer1
+    app: org2-peer1
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: org2-peer-gateway-svc
+spec:
+  ports:
+    - name: gossip
+      port: 7051
+      protocol: TCP
+  selector:
+    org: org2
diff --git a/test-network-k8s/kube/org2/org2-peer2.yaml b/test-network-k8s/kube/org2/org2-peer2.yaml
@@ -43,6 +43,7 @@ spec:
     metadata:
       labels:
         app: org2-peer2
+        org: org2
     spec:
       containers:
         - name: main

diff --git a/test-network-k8s/scripts/application_connection.sh b/test-network-k8s/scripts/application_connection.sh
@@ -100,8 +100,8 @@ data:
   fabric_channel: ${CHANNEL_NAME}
   fabric_contract: ${CHAINCODE_NAME}
   fabric_wallet_dir: /fabric/application/wallet
-  fabric_gateway_hostport: org1-peer1:7051
-  fabric_gateway_sslHostOverride: org1-peer1
+  fabric_gateway_hostport: org1-peer-gateway-svc:7051
+  fabric_gateway_sslHostOverride: org1-peer-gateway-svc
   fabric_user: appuser_org1
   fabric_gateway_tlsCertPath: /fabric/tlscacerts/org1-tls-ca.pem
 EOF

diff --git a/test-network-k8s/scripts/chaincode.sh b/test-network-k8s/scripts/chaincode.sh
@@ -111,10 +111,27 @@ function query_chaincode_metadata() {
   set -x
   local args='{"Args":["org.hyperledger.fabric:GetMetadata"]}'
   # todo: mangle additional $@ parameters with bash escape quotations
+  log 'Org1-Peer1:'
   echo '
   export CORE_PEER_ADDRESS=org1-peer1:7051
   peer chaincode query -n '${CHAINCODE_NAME}' -C '${CHANNEL_NAME}' -c '"'$args'"'
   ' | exec kubectl -n $NS exec deploy/org1-admin-cli -c main -i -- /bin/bash
+
+  log ''
+  log 'Org1-Peer2:'
+  echo '
+  export CORE_PEER_ADDRESS=org1-peer2:7051
+  peer chaincode query -n '${CHAINCODE_NAME}' -C '${CHANNEL_NAME}' -c '"'$args'"'
+  ' | exec kubectl -n $NS exec deploy/org1-admin-cli -c main -i -- /bin/bash
+
+  log ''
+  log 'Org1-Peer-SVC:'
+  echo '
+  export CORE_PEER_ADDRESS=org1-peer-svc:7051
+  peer chaincode query -n '${CHAINCODE_NAME}' -C '${CHANNEL_NAME}' -c '"'$args'"'
+  ' | exec kubectl -n $NS exec deploy/org1-admin-cli -c main -i -- /bin/bash
+
+
 }
 
 function invoke_chaincode() {

diff --git a/test-network-k8s/scripts/kind.sh b/test-network-k8s/scripts/kind.sh
@@ -54,6 +54,8 @@ function kind_create() {
   local ingress_http_port=${NGINX_HTTP_PORT}
   local ingress_https_port=${NGINX_HTTPS_PORT}
 
+  # the 'ipvs'proxy mode permits better HA abilities
+
   cat <<EOF | kind create cluster --name $CLUSTER_NAME --config=-
 ---
 kind: Cluster
@@ -73,6 +75,8 @@ nodes:
       - containerPort: 443
         hostPort: ${ingress_https_port}
         protocol: TCP
+networking:
+  kubeProxyMode: "ipvs"
 
 # create a cluster with the local registry enabled in containerd
 containerdConfigPatches:

diff --git a/test-network-k8s/scripts/test_network.sh b/test-network-k8s/scripts/test_network.sh
@@ -108,8 +108,8 @@ function create_org1_local_MSP() {
   fabric-ca-client register --id.name org1-peer2 --id.secret peerpw --id.type peer --url https://org1-ecert-ca --mspdir $FABRIC_CA_CLIENT_HOME/org1-ecert-ca/rcaadmin/msp
   fabric-ca-client register --id.name org1-admin --id.secret org1adminpw  --id.type admin   --url https://org1-ecert-ca --mspdir $FABRIC_CA_CLIENT_HOME/org1-ecert-ca/rcaadmin/msp --id.attrs "hf.Registrar.Roles=client,hf.Registrar.Attributes=*,hf.Revoker=true,hf.GenCRL=true,admin=true:ecert,abac.init=true:ecert"
 
-  fabric-ca-client enroll --url https://org1-peer1:peerpw@org1-ecert-ca --csr.hosts org1-peer1 --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org1.example.com/peers/org1-peer1.org1.example.com/msp
-  fabric-ca-client enroll --url https://org1-peer2:peerpw@org1-ecert-ca --csr.hosts org1-peer2 --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org1.example.com/peers/org1-peer2.org1.example.com/msp
+  fabric-ca-client enroll --url https://org1-peer1:peerpw@org1-ecert-ca --csr.hosts org1-peer1,org1-peer-gateway-svc --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org1.example.com/peers/org1-peer1.org1.example.com/msp
+  fabric-ca-client enroll --url https://org1-peer2:peerpw@org1-ecert-ca --csr.hosts org1-peer2,org1-peer-gateway-svc --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org1.example.com/peers/org1-peer2.org1.example.com/msp
   fabric-ca-client enroll --url https://org1-admin:org1adminpw@org1-ecert-ca  --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org1.example.com/users/[email protected]/msp
 
   # Each node in the network needs a TLS registration and enrollment.
@@ -158,8 +158,8 @@ function create_org2_local_MSP() {
   fabric-ca-client register --id.name org2-peer2 --id.secret peerpw --id.type peer --url https://org2-ecert-ca --mspdir $FABRIC_CA_CLIENT_HOME/org2-ecert-ca/rcaadmin/msp
   fabric-ca-client register --id.name org2-admin --id.secret org2adminpw  --id.type admin   --url https://org2-ecert-ca --mspdir $FABRIC_CA_CLIENT_HOME/org2-ecert-ca/rcaadmin/msp --id.attrs "hf.Registrar.Roles=client,hf.Registrar.Attributes=*,hf.Revoker=true,hf.GenCRL=true,admin=true:ecert,abac.init=true:ecert"
 
-  fabric-ca-client enroll --url https://org2-peer1:peerpw@org2-ecert-ca --csr.hosts org2-peer1 --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org2.example.com/peers/org2-peer1.org2.example.com/msp
-  fabric-ca-client enroll --url https://org2-peer2:peerpw@org2-ecert-ca --csr.hosts org2-peer2 --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org2.example.com/peers/org2-peer2.org2.example.com/msp
+  fabric-ca-client enroll --url https://org2-peer1:peerpw@org2-ecert-ca --csr.hosts org2-peer1,org2-peer-gateway-svc --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org2.example.com/peers/org2-peer1.org2.example.com/msp
+  fabric-ca-client enroll --url https://org2-peer2:peerpw@org2-ecert-ca --csr.hosts org2-peer2,org2-peer-gateway-svc --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org2.example.com/peers/org2-peer2.org2.example.com/msp
   fabric-ca-client enroll --url https://org2-admin:org2adminpw@org2-ecert-ca  --mspdir /var/hyperledger/fabric/organizations/peerOrganizations/org2.example.com/users/[email protected]/msp
 
   # Each node in the network needs a TLS registration and enrollment.