Currently, I am getting the ECONNREFUSED where node can't connect to the database. I am not sure where the database host is supposed to end up. Should I be using localhost:7474, 127.0.0.1:7474, 0.0.0.0:7474, or am I supposed to use some host that gets generated when I get my Kubernetes pods up that I can somehow pass in? e.g. like $(minikube ip) = 192.168.90.100:7474, but for my database? Is there an ENV containing the database host that I am supposed to be pulling from somewhere?
const neo4jDatabase = connect({
server: 'http://<what goes here!?>:7474',
user: process.env.DB_USER,
pass: process.env.DB_PASS,
});
I seem to have gotten the pods running with the below .yml configs, but am not sure if the neo4j one is correct.
NAME READY STATUS RESTARTS AGE
neo4j-4166717986-8qbwq 1/1 Running 0 41m
node-481322091-g27md 1/1 Running 0 11mnode.yml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: node
spec:
replicas: 1
template:
metadata:
labels:
app: node
tier: backend
track: stable
spec:
containers:
- name: node
image: "myapp"
ports:
- name: nodeport
containerPort: 8080
env:
- name: DB_USER
valueFrom:
configMapKeyRef:
name: config
key: db_user
- name: DB_PASS
valueFrom:
configMapKeyRef:
name: config
key: db_pass
---
apiVersion: v1
kind: Service
metadata:
name: node
spec:
selector:
app: node
tier: backend
ports:
- protocol: TCP
port: 80
targetPort:
type: LoadBalancerneo4j.yml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: neo4j
spec:
template:
metadata:
labels:
run: neo4j
spec:
containers:
- name: neo4j
image: "my-neo4j"
ports:
- containerPort: 7474
---
apiVersion: v1
kind: Service
metadata:
name: neo4j
labels:
run: neo4j
spec:
selector:
run: neo4j
ports:
- port: 7474
targetPort: 7474
protocol: TCPPerhaps a less known feature of Kubernetes is the fact that some magic environment variables are injected in the running pods.
In your particular case, pods have an environment variable for each service in the namespace. The format is the following:
<your service>_SERVICE_HOST
<your service name>_SERVICE_PORT_EXPOSED_PORTYou can verify this is true by attaching to a running pod with kubectl exec -ti <your pod id> sh and issuing a printenv command.
Please note that if the service was created AFTER the pod, you have to delete the pod with kubectl delete pod <your pod id> to force recreation (and injection) of the environment variables.
In your case, the final code will look like this:
const serviceHost = process.ENV.NEO4J_SERVICE_HOST;
const servicePort = process.ENV.NEO4J_SERVICE_PORT_EXPOSED_PORT;
const neo4jDatabase = connect({
server: `http://${serviceHost}:${servicePort}`,
user: process.env.DB_USER,
pass: process.env.DB_PASS,
});