add operator faqs (#2134)

* add operator faqs

* Update 7.operator-faq.md

docs-2.0/nebula-operator/3.deploy-nebula-graph-cluster/3.1create-cluster-with-kubectl.md

@@ -153,7 +153,7 @@ The following shows how to scale out a NebulaGraph cluster by changing the numbe
 3. Check the number of Storage services.
 
   ```bash
-  kubectl  get pods -l app.kubernetes.io/cluster=nebula
+  kubectl get pods -l app.kubernetes.io/cluster=nebula
   ```
 
   Output:

docs-2.0/nebula-operator/7.operator-faq.md

@@ -15,3 +15,52 @@ It is suggested to back up data in advance so that you can roll back data in cas
 ## Is the replica in the Operator docs the same as the replica in the NebulaGraph core docs?
 
 They are different concepts. A replica in the Operator docs indicates a pod replica in K8s, while a replica in the core docs is a replica of a NebulaGraph storage partition.
+
+
+## How to view the logs of each service in the NebulaGraph cluster?
+
+The logs for the NebulaGraph cluster are not gathered in the K8s cluster, which also means that they cannot be retrieved through the `kubectl logs` command. To obtain the logs of each cluster service, you need to access the container and view the log files that are stored inside. This is the only option available for users to get the service logs individually in the NebulaGraph cluster.
+
+Steps to view the logs of each service in the NebulaGraph cluster:
+
+```bash
+# To view the name of the pod where the container you want to access is located. 
+# Replace <cluster-name> with the name of the cluster.
+kubectl get pods -l app.kubernetes.io/cluster=<cluster-name>
+
+# To access the container within the pod, such as the nebula-graphd-0 container.
+kubectl exec -it nebula-graphd-0 -- /bin/bash
+
+# To go to /usr/local/nebula/logs directory to view the logs.
+cd /usr/local/nebula/logs
+```
+
+## How to resolve the `host not found:nebula-<metad|storaged|graphd>-0.nebula.<metad|storaged|graphd>-headless.default.svc.cluster.local` error?
+
+This error is generally caused by a DNS resolution failure, and you need to check whether the cluster domain has been modified. If the cluster domain has been modified, you need to modify the `kubernetesClusterDomain` field in the NebulaGraph Operator configuration file accordingly. The steps for modifying the Operator configuration file are as follows:
+
+1. View the Operator configuration file.
+
+  ```yaml 
+  [abby@master ~]$ helm show values nebula-operator/nebula-operator   
+  image:
+    nebulaOperator:
+      image: vesoft/nebula-operator:{{operator.tag}}
+      imagePullPolicy: Always
+    kubeRBACProxy:
+      image: gcr.io/kubebuilder/kube-rbac-proxy:v0.13.0
+      imagePullPolicy: Always
+    kubeScheduler:
+      image: registry.k8s.io/kube-scheduler:v1.24.11
+      imagePullPolicy: Always
+
+  imagePullSecrets: []
+  kubernetesClusterDomain: ""  # The cluster domain name, and the default is cluster.local.
+  ```
+
+2. Modify the value of the `kubernetesClusterDomain` field to the updated cluster domain name.
+
+  ```
+  helm upgrade nebula-operator nebula-operator/nebula-operator --namespace=<nebula-operator-system> --version={{operator.release}} --set kubernetesClusterDomain=<cluster-domain>
+  ```
+  <nebula-operator-system> is the namespace where Operator is located and <cluster-domain> is the updated domain name.

mkdocs.yml

@@ -240,11 +240,11 @@ extra:
     branch: release-1.2
     tag: v1.2.0
   operator:
-    release: 1.5.0
-    tag: v1.5.0
-    branch: release-1.5
+    release: 1.4.2
+    tag: v1.4.2
+    branch: release-1.4
     upgrade_from: 3.0.0
-    upgrade_to: 3.5.0
+    upgrade_to: 3.4.1
   exporter:
     release: 3.3.0
     branch: release-3.3