Add troubleshooting guide for notebooks (kubeflow#1008)

* feat: add template of troubleshooting guide for notebooks

* feat: improve the notebooks troubleshooting guide

* fix: improve the note for GCP users

* fix: minor bug in the link

* fix: improve the troubleshooting guide

* fix: fix troubleshooting guides

content/docs/notebooks/setup.md

@@ -265,4 +265,6 @@ exposed to the internet and is an unsecured endpoint by default.
 * Learn the advanced features available from a Kubeflow notebook, such as
   [submitting Kubernetes resources](/docs/notebooks/submit-kubernetes/) or
   [building Docker images](/docs/notebooks/submit-docker-image/). 
-
+* Visit the [troubleshooting guide](/docs/notebooks/troubleshoot) for fixing common
+  errors in creating Jupyter notebooks in Kubeflow
+

content/docs/notebooks/troubleshoot.md

@@ -0,0 +1,95 @@
++++
+title = "Troubleshooting Guide"
+description = "Fixing common problems in Kubeflow notebooks"
+weight = 50
++++
+
+## Persistent Volumes and Persistent Volumes Claims
+
+First, make sure that PVCs are bounded when using Jupter notebooks. This should
+not be a problem when using managed Kuberenetes. But if you are using Kubernetes
+on-prem, check out the guide to [Kubeflow on-prem in a multi-node Kubernetes cluster](/docs/use-cases/kubeflow-on-multinode-cluster/) if you are running Kubeflow in multi-node on-prem environment. Otherwise, look at the [Pods stuck in Pending State](/docs/other-guides/troubleshooting/#pods-stuck-in-pending-state) guide to troubleshoot this problem.
+
+## Check the status of notebooks
+
+Run the commands below.
+
+```
+kubectl get notebooks -o yaml ${NOTEBOOK}
+kubectl describe notebooks ${NOTEBOOK}
+```
+
+Check the `events` section to make sure that there are no errors.
+
+## Check the status of statefulsets
+
+Make sure that the number of `statefulsets` equals the desired number. If it is
+not the case, check for errors using the `kubectl describe`. 
+
+
+```
+kubectl get statefulsets -o yaml ${NOTEBOOK}
+kubectl describe statefulsets ${NOTEBOOK}
+```
+
+
+The output should look like below:
+```
+NAME            DESIRED   CURRENT   AGE
+your-notebook   1         1         9m4s
+```
+## Check the status of Pods
+
+If the number of statefulsets didn't match the desired number, make sure that 
+the number of Pods match the number of desired Pods in the first  command. 
+In case it didn't match, follow the steps below to further investigate the issue.
+
+```
+kubectl get pod -o yaml ${NOTEBOOK}-0
+```
+
+* The name of the Pod should start with `jupter`
+* If you are using username/password auth with Jupyter the pod will be named
+
+```
+jupyter-${USERNAME}
+```
+
+* If you are using IAP on GKE the pod will be named
+
+```
+jupyter-accounts-2egoogle-2ecom-3USER-40DOMAIN-2eEXT
+```
+    * Where USER@DOMAIN.EXT is the Google account used with IAP
+
+Once you know the name of the pod do
+
+```
+kubectl describe pod ${NOTEBOOK}-0
+```
+
+* Look at the `events` to see if there are any errors trying to schedule the pod
+* One common error is not being able to schedule the pod because there aren’t enough resources in the cluster.
+
+
+If the error still persisted, check for the errors in the logs of containers.
+
+```
+kubectl logs ${NOTEBOOK}-0
+```
+
+## Note for GCP Users
+
+You may encounter error below:
+```
+Type     Reason        Age                     From                    Message
+----     ------        ----                    ----                    -------
+Warning  FailedCreate  2m19s (x26 over 7m39s)  statefulset-controller  create Pod test1-0 in StatefulSet test1 failed error: pods "test1-0" is forbidden: error looking up service account kubeflow/default-editor: serviceaccount "default-editor" not found
+```
+
+To fix this problem, create a service account named `default-editor` with cluster-admin role.
+
+```
+kubectl create sa default-editor
+kubectl create clusterrolebinding cluster-admin-binding --clusterrole cluster-admin --user default-editor
+```

content/docs/other-guides/troubleshooting.md

@@ -78,37 +78,8 @@ how RBAC interacts with IAM on GCP.
 
 ## Problems spawning Jupyter pods
 
-If you're having trouble spawning Jupyter notebooks, check that the pod is getting
-scheduled
+This section has been moved to [Jupyter Notebooks Troubleshooting Guide] (/docs/notebooks/troubleshoot/).
 
-```
-kubectl -n ${NAMESPACE} get pods
-```
-
-  * Look for pods whose name starts with juypter
-  * If you are using username/password auth with Jupyter the pod will be named
-
-  ```
-  jupyter-${USERNAME}
-  ```
-
-  * If you are using IAP on GKE the pod will be named
-
-    ```
-    jupyter-accounts-2egoogle-2ecom-3USER-40DOMAIN-2eEXT
-    ```
-
-    * Where USER@DOMAIN.EXT is the Google account used with IAP
-
-Once you know the name of the pod do
-
-```
-kubectl -n ${NAMESPACE} describe pods ${PODNAME}
-```
-
-  * Look at the events to see if there are any errors trying to schedule the pod
-  * One common error is not being able to schedule the pod because there aren't
-    enough resources in the cluster.
 
 ## Pods stuck in Pending state