How to connect to mongodb replicaset (k8s) using compass

Question

I installed mongodb as a replicaset with 3 replicas on my k8s cluster using the bitnami helm chart.

So I get these pods:

mongodb-0.mongodb-headless.mongodb.svc.cluster.local:27017
mongodb-1.mongodb-headless.mongodb.svc.cluster.local:27017
mongodb-2.mongodb-headless.mongodb.svc.cluster.local:27017

Now I would like to get access using mongodb compass.

I set a port forward (at 27017 I'm running a local mongodb)

kubectl port-forward svc/mongodb-headless -n mongodb 27018:27017

and tried to connect compass with the uri

mongodb://localhost:27018

But this gives me the error

getaddrinfo ENOTFOUND mongodb-0.mongodb-headless.mongodb.svc.cluster.local

What am I doing wrong to connect to my k8s cluster mongodb using compass?

Update

% kubectl get all -n mongodb

NAME                    READY   STATUS    RESTARTS   AGE
pod/mongodb-0           1/1     Running   0          25h
pod/mongodb-1           1/1     Running   0          25h
pod/mongodb-2           1/1     Running   0          25h
pod/mongodb-arbiter-0   1/1     Running   0          2d14h

NAME                               TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)     AGE
service/mongodb-arbiter-headless   ClusterIP   None         <none>        27017/TCP   2d14h
service/mongodb-headless           ClusterIP   None         <none>        27017/TCP   2d14h

NAME                               READY   AGE
statefulset.apps/mongodb           3/3     2d14h
statefulset.apps/mongodb-arbiter   1/1     2d14h

values.yaml for bitnami helm chart

image:
  registry: docker.io
  repository: bitnami/mongodb
  digest: "sha256:916202d7af766dd88c2fff63bf711162c9d708ac7a3ffccd2aa812e3f03ae209" # tag: 4.4.15
  pullPolicy: IfNotPresent
architecture: replicaset
replicaCount: 2
updateStrategy:
  type: RollingUpdate
containerPorts:
  mongodb: 27017
auth:
  enabled: true
  rootUser: root
  rootPassword: "password"
  usernames: ["user"]
  passwords: ["userpass"]
  databases: ["db"]

service:
  portName: mongodb
  ports:
    mongodb: 27017

persistence:
  enabled: true
  accessModes:
    - ReadWriteOnce
  size: 8Gi

volumePermissions:
  enabled: true

livenessProbe:
  enabled: false
readinessProbe:
  enabled: false

pls provide all the outputs for your ns, i.e `kubectl get all` also it'd be useful to show svc YAMLs — Konstantin Vustin, Nov 16 '22 at 10:42

Konstantin Vustin · Accepted Answer · 2022-11-17T10:34:30.590

Just have recreated your setup. Everything works fine

$ k create ns mongo-test
namespace/mongo-test created

$ k -n mongo-test create -f mongo-svc-sts.yaml
statefulset.apps/mongo created
service/mongo-headless created

result

$ k -n mongo-test get all
NAME          READY   STATUS    RESTARTS   AGE
pod/mongo-0   1/1     Running   0          44s
pod/mongo-1   1/1     Running   0          40s
pod/mongo-2   1/1     Running   0          27s

NAME                     TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)     AGE
service/mongo-headless   ClusterIP   None         <none>        27017/TCP   13m

NAME                     READY   AGE
statefulset.apps/mongo   3/3     45s

port forward

$ k -n mongo-test port-forward svc/mongo-headless 27018:27017
Forwarding from 127.0.0.1:27018 -> 27017
Forwarding from [::1]:27018 -> 27017
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018
Handling connection for 27018

compass

mongo-svc-sts.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mongo
spec:
  serviceName: "mongo"
  replicas: 3
  selector:
    matchLabels:
      app.kubernetes.io/name: mongo
      app.kubernetes.io/component: backend
  template:
    metadata:
      labels:
        app.kubernetes.io/name: mongo
        app.kubernetes.io/component: backend
    spec:
      tolerations:
        - operator: Exists
      containers:
      - name: mongo
        image: mongo:latest
        args:
          - --bind_ip
          - 0.0.0.0
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
        ports:
        - containerPort: 27017
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: mongo
    service: logging
  name: mongo-headless
spec:
  type: ClusterIP
  clusterIP: None
  ports:
  - port: 27017
  selector:
    app.kubernetes.io/name: mongo
    app.kubernetes.io/component: backend

to be able to help you pls use that YAMLs and post the outputs. If it does not work probably you should debug your k8s installation

Is `architecture: replicaset`wrong? I've added the values.yaml file of the helm chart to my post. — user3142695, Nov 17 '22 at 13:01

score 1 · Answer 2 · answered Nov 17 '22 at 10:33

1

It's work with port forward and compass with some configuration in compass, using advence options with Direct Connection : And don't add replicat set option.

answered Nov 17 '22 at 10:33

Mr_Thorynque

1,749
1
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31

It is nearly working. I can connect, but I do get `An error occurred while loading instance info: command hostInfo requires authentication`. So I only have to use one of the nodes? Not all three? – user3142695 Nov 17 '22 at 14:31
Maybe you need to add /admin?authSource=admin if you use standard config in your mongo connection string. – Mr_Thorynque Nov 17 '22 at 17:00
also should set the replicaset name in advanced tab – Gentle Song Aug 14 '23 at 09:12

Mr_Thorynque · Answer 3 · 2022-11-17T09:08:25.697

For what I know (and I use), it isn't possible to use port forwarding to connect mongo replica set with Compass (you can not use a local port twice or more times...) To me that because compass use the topology that replica set use. So you need to be compliant of that topology from your client computer.

So you can expose the mongo pods with Cluster IP, manage your hosts file to match kubernetes nodes.

And use standard connection string like you are in kubernetes :

UPDATE : You can configure mongo helm to do cluster https://artifacthub.io/packages/helm/bitnami/mongodb

And you hosts file :

external_IP1 mongodb-0.mongodb-headless.mongodb.svc.cluster.local

external_IP2 mongodb-1.mongodb-headless.mongodb.svc.cluster.local

Could you please explain `...expose the mongo pods with Cluster IP, manage your hosts file to match kubernetes nodes.`? — user3142695, Nov 16 '22 at 17:56

R2D2 · Answer 4 · 2022-11-17T20:24:29.437

0

You can create 3x nodePort services for the task , example exposure for mongodb-0 pod:

kind: Service 
apiVersion: v1 
metadata:
  name: mongodb-0
spec:
  type: NodePort
  selector:
    statefulset.kubernetes.io/pod-name: mongodb-0
  ports:
    - nodePort: 30117
      port: 27017
      targetPort: 27017
      protocol: TCP

And you can connect with COMPASS via the k8s worker nodes exposed nodePort's as follow:

  connect: mongodb://workernode:30117

assuming that you have created 3x nodePort's -> 30117,30118,30119 for the three pods and your bitnami helmchart is using statefulset to manage the pods so the pod names are: mongodb-0,1,2

edited Nov 17 '22 at 20:24

answered Nov 16 '22 at 22:25

R2D2

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2
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1

Does it work or not? – Alex Blex Nov 17 '22 at 02:03
Is workernode = mongodb-0.mongodb-headless.mongodb.svc.cluster.local? – user3142695 Nov 22 '22 at 14:05

How to connect to mongodb replicaset (k8s) using compass

4 Answers4