Kubernetes HostPort with dnsmasq issue [closed] - kubernetes

Question

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack Exchange site, you can leave a comment to explain where the question may be able to be answered.
Closed 1 year ago.
Improve this question
I'm trying to setup a dnsmasq pod via kubernetes. Yaml file is like below:
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: dnsmasq1
labels:
name: dnsmasq1
spec:
serviceName: "dnsmasq1"
replicas: 1
selector:
matchLabels:
name: dnsmasq1
volumeClaimTemplates:
- metadata:
name: dnsmasqconf-pv1
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
storageClassName: ceph-rbd-sc
template:
metadata:
labels:
name: dnsmasq1
spec:
hostNetwork: false
affinity:
podAntiAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchLabels:
name: dnsmasq1
topologyKey: "kubernetes.io/hostname"
hostname: dnsmasq1
containers:
- name: dnsmasq1
image: jpillora/dnsmasq
ports:
- containerPort: 8080
hostPort: 8082
imagePullPolicy: IfNotPresent
env:
- name: HTTP_USER
value: "****"
- name: HTTP_PASS
value: "****"
volumeMounts:
- mountPath: /mnt/config
name: dnsmasqconf-pv1
resources:
requests:
memory: 250Mi
limits:
memory: 250Mi
nodeSelector:
etiket: worker
dnsPolicy: "None"
dnsConfig:
nameservers:
- 8.8.8.8
volumes:
- name: dnsmasqconf-pv1
persistentVolumeClaim:
claimName: dnsmasqconf-pv1
This works fine and I can reach to pod using the node's IP address. I decided to test the pod as a dns server on a test machine but the entries are not resolved. I think this is because I'm not using the Pod's IP as dns server but the node's. How can I set this pod to be used a dns server externally? I don't have a cloud provider so I don't think I can use loadbalancer IP here.

Answer 1

I don't think you can use dnsmasq as external dns server as dnsmasq is a lightweight DNS forwarder, designed to provide DNSservices to a small-scale network. It can serve the names of local machines which are not in the global DNS. dnsmasq makes it simple to specify the nameserver to use for a given domain and it is ideal to manage communication in a kubernetes cluster.
In /etc/NetworkManager/NetworkManager.conf, add or uncomment the following line in the [main] section:
dns=dnsmasq
Create /etc/NetworkManager/dnsmasq.d/kube.conf with this line:
server=/cluster.local/10.90.0.10
This tells dnsmasq that queries for anything in the cluster.local domain should be forwarded to the DNS server at 10.90.0.10. This happens to be the default IP address of the kube-dns service in the kube-system namespace. If your cluster’s DNS service has a different IP address, you’ll need to specify it instead.
Now, after you run systemctl restart NetworkManager, your /etc/resolv.conf should look something like this:
#Generated by NetworkManager
search localdomain
nameserver 127.0.0.1
The important line is nameserver 127.0.0.1. This means DNS requests are sent to localhost, which is handled by dnsmasq.