how to connect to local network from kubernetes pod

Question

I have a k8s cluster set up on a few raspberry pis for local development. I am trying to use a database running in the local network however I can't seem to get the pods to connect to the db. I have tried using a service and endpoint configuration:

---
apiVersion: v1
kind: Service
metadata:
  name: {{ .Values.database.host }}
  annotations:
    "helm.sh/hook-weight": "-2"
    "helm.sh/hook": pre-install,pre-upgrade
    "helm.sh/hook-delete-policy": before-hook-creation
spec:
  clusterIP: None
  ports:
    - port: {{ .Values.database.port }}
---
apiVersion: v1
kind: Endpoints
metadata:
  name: {{ .Values.database.host }}
  annotations:
    "helm.sh/hook-weight": "-2"
    "helm.sh/hook": pre-install,pre-upgrade
    "helm.sh/hook-delete-policy": before-hook-creation
subsets:
  - addresses:
      - ip: {{ .Values.database.ip }}
    ports:
      - port: {{ .Values.database.port }}
        name: {{ .Values.database.host }}

I can confirm that the endpoint and service resources are created and that all the connection details are correct but my application (running on the k8s cluster) still will not connect to the database on the host network. Reading the documentation closer it sounds like these resources are for connecting to the cluster from the local network, not the other way around? Is there a way to connect to services on a local network from k8s resources?

result of running kubectl get pods -n kube-system

local-path-provisioner-5ff76fc89d-txj6k   1/1     Running   4          65d
metrics-server-86cbb8457f-r8q6w           1/1     Running   3          65d
coredns-7448499f4d-5646n                  1/1     Running   10         176d
csi-smb-node-9j5gm                        3/3     Running   3291       150d
csi-smb-controller-6c696945f8-8t6qj       3/3     Running   27         150d
csi-smb-controller-6c696945f8-ck5hh       3/3     Running   3361       150d
csi-smb-node-822bb                        3/3     Running   3260       150d
csi-smb-node-4nckf                        3/3     Running   3655       150d

Answer 1

Turns out that the issue was not a kubernetes one, but a configuration issue. I was able to solve the problem I was experiencing by modifying the postgres hba configuration file to have a broader range of ip addresses. As mentioned by @gohm'c there are many resources online describing how to fix the connection error that I was encountering. Thanks to @gohm'c for their help in debugging.