added doc on how to setup NFS server and client

docs/other-tools/nfs/nfs-server-client-setup.md

@@ -0,0 +1,259 @@
+# Network File System (NFS)
+
+NFS enables a system to share directories and files with others over a network.
+With NFS, users and applications can access files on remote systems as if they
+were stored locally. Client systems mount a directory hosted on the NFS server,
+allowing them to access and work with the files it contains.
+
+## Pre-requisite
+
+We are using following setting for this purpose to setup the NFS server and
+client on Ubuntu based NERC OpenStack VM:
+
+-   1 Linux machine for the **NFS Server**, `ubuntu-22.04-x86_64`, `cpu-su.1` flavor
+    with 1vCPU, 4GB RAM, 20GB storage - also [assign Floating IP](../../openstack/create-and-connect-to-the-VM/assign-a-floating-IP.md). Note the NFS Server's Internal IP i.e. `<NFS_SERVER_INTERNAL_IP>`
+    i.e. `192.168.0.73` in this example.
+
+-   1 Linux machine for the **NFS Client**, `ubuntu-22.04-x86_64`, `cpu-su.1` flavor
+    with 1vCPU, 4GB RAM, 20GB storage - also [assign Floating IP](../../openstack/create-and-connect-to-the-VM/assign-a-floating-IP.md).
+
+-   ssh access to both machines: [Read more here](../../openstack/create-and-connect-to-the-VM/bastion-host-based-ssh/index.md)
+    on how to set up SSH on your remote VMs.
+
+-   Create a security group with a rule that opens **Port 2049** (the default
+    *NFS* port) for file sharing. Update Security Group to the **NFS Server** VM
+    only following [this reference](../../openstack/access-and-security/security-groups.md#update-security-groups-to-a-running-vm).
+
+## Installing and configuring NFS Server
+
+1. Update System Packages:
+
+    ```sh
+    sudo apt-get update && sudo apt-get upgrade -y
+    ```
+
+2. Install NFS Kernel Server:
+
+    ```sh
+    sudo apt install nfs-kernel-server -y
+    ```
+
+3. Create a directory you want to share over the network:
+
+    ```sh
+    sudo mkdir -p /mnt/nfs_share
+    ```
+
+4. Set the ownership and permissions to allow access (adjust based on requirements):
+
+    Since we want all the client machines to access the shared directory, remove
+    any restrictions in the directory permissions.
+
+    ```sh
+    sudo chown -R nobody:nogroup /mnt/nfs_share/
+    ```
+
+    You can also tweak the file permissions to your preference. Here's we have given
+    the read, write and execute privileges to all the contents inside the directory.
+
+    ```sh
+    sudo chmod 777 /mnt/nfs_share/
+    ```
+
+5. Configure NFS Exports:
+
+    Edit the `/etc/exports` file to define shared directories and permissions.
+    Permissions for accessing the NFS server are defined in the `/etc/exports` file.
+    So open the file using your favorite text editor i.e. nano editor:
+
+    ```sh
+    sudo nano /etc/exports
+    ```
+
+    !!! tip "Define Shared Directories and Permissions"
+
+        You can provide access to a single client, multiple clients, or specify
+        an entire subnet.
+
+        To grant access to a single client, use the syntax:
+
+        ```sh
+        /mnt/nfs_share  Client_Internal_IP_1(rw,sync,no_subtree_check)
+        ```
+
+        For multiple clients, specify each client on a separate file:
+
+        ```sh
+        /mnt/nfs_share  Client_Internal_IP_1(rw,sync,no_subtree_check)
+        /mnt/nfs_share  Client_Internal_IP_2(rw,sync,no_subtree_check)
+        ```
+
+    Add a line like this to share the directory with read/write permissions for a
+    subnet (e.g., 192.168.1.0/24):
+
+    ```sh
+    /mnt/nfs_share 192.168.1.0/24(rw,sync,no_subtree_check)
+    ```
+
+    **Explanation:**
+
+    -   **rw**: Read and write access.
+    -   **sync**: Changes are written to disk immediately.
+    -   **no_subtree_check**: Avoid permission issues for subdirectories.
+
+    !!! info "Other Options for Directory Permissions for the NFS share directory"
+
+        You can configure the shared directories to be exported by adding them to
+        the `/etc/exports` file. For example:
+
+        ```
+        /srv     *(ro,sync,subtree_check)
+        /home    *.hostname.com(rw,sync,no_subtree_check)
+        /scratch *(rw,async,no_subtree_check,no_root_squash)
+        ```
+
+        For more information [read here](https://ubuntu.com/server/docs/network-file-system-nfs#configuration).
+
+6. Apply Export Settings with the shared directories:
+    
+    ```sh
+    sudo exportfs -rav
+    ```
+
+7. Retart NFS Service:
+
+    ```sh
+    sudo systemctl restart nfs-kernel-server
+    ```
+
+## Configure the NFS Client on the Client VM
+
+1. Update System Packages:
+
+    ```sh
+    sudo apt-get update && sudo apt-get upgrade -y
+    ```
+
+2. On the Client VM, install the required NFS package:
+
+    ```sh
+    sudo apt install nfs-common -y
+    ```
+
+3. Create a Mount Point:
+
+    Create a local directory where the shared NFS directory will be mounted:
+
+    ```sh
+    sudo mkdir -p /mnt/nfs_clientshare
+    ```
+
+4. Testing connectivity between the Client and Server using the `showmount` command:
+
+    ```sh
+    showmount --exports <NFS_SERVER_INTERNAL_IP>
+    ```
+
+    For e.g.,
+
+    ```sh
+    showmount --exports 192.168.0.73
+
+    Export list for 192.168.0.73:
+    /mnt/nfs_share 192.168.0.0/24
+    ```
+
+5. Mount the Shared Directory:
+
+    Use the `mount` command to connect to the **NFS Server** and mount the directory.
+
+    ```sh
+    sudo mount -t nfs <NFS_SERVER_INTERNAL_IP>:/mnt/nfs_share /mnt/nfs_clientshare
+    ```
+
+    For e.g.,
+
+    ```sh
+    sudo mount -t nfs 192.168.0.73:/mnt/nfs_share /mnt/nfs_clientshare
+    ```
+
+6. Verify the Mount:
+    
+    Check if the directory is mounted successfully.
+
+    ```sh
+    df -h
+    ```
+
+You should see the NFS share listed that is mounted and accessible.
+
+!!! info "How to **Unmount** Shared Directory, if not needed!"
+
+    When you're finished with a mount, we can unmount it with the `umount` command.
+
+    ```sh
+    sudo umount /mnt/nfs_clientshare
+    ```
+
+## Make the Mount Persistent on the Client VM
+
+An alternate way to mount an NFS share from another machine is to add a line to
+the `/etc/fstab` file. The line must state the Floating IP of the **NFS Server**,
+the directory on the *NFS Server* being exported, and the directory on the local
+Client VM where the NFS share is to be mounted. This will ensure the NFS share
+is mounted automatically even after the Client VM is rebooted at the boot time.
+
+The general syntax for the line in `/etc/fstab` file is as follows:
+
+```sh
+example.hostname.com:/srv /opt/example nfs rsize=8192,wsize=8192,timeo=14,intr
+```
+
+1. Edit `/etc/fstab` Open the file:
+
+    ```sh
+    sudo nano /etc/fstab
+    ```
+
+2. Add an entry like this:
+
+    ```sh
+    <NFS_SERVER_INTERNAL_IP>:/mnt/nfs_share /mnt/nfs_clientshare nfs defaults 0 0
+    ```
+
+    For e.g.,
+
+    ```sh
+    192.168.0.73:/mnt/nfs_share /mnt/nfs_clientshare nfs defaults 0 0
+    ```
+
+3. Test the Configuration Unmount and remount all filesystems listed in `/etc/fstab`:
+
+    ```sh
+    sudo umount /mnt/nfs_clientshare
+    sudo mount -a
+    ```
+
+4. Verify the Mount:
+
+    Check if the directory is mounted successfully.
+
+    ```sh
+    df -h
+    ```
+
+## Test the Setup
+
+- On the **NFS Server**, write a test file:
+
+    ```sh
+    echo "Hello from NFS Server" | sudo tee /mnt/nfs_share/test.txt
+    ```
+
+- On the **NFS Client**, verify the file is accessible:
+
+    ```sh
+    cat /mnt/nfs_clientshare/test.txt
+    ```
+
+---

mkdocs.yaml

@@ -156,6 +156,7 @@ nav:
                 - Using Github Actions:
                       - GitHub Actions CI/CD Pipeline: other-tools/CI-CD/github-actions/setup-github-actions-pipeline.md
           - Apache Spark: other-tools/apache-spark/spark.md
+          - Setup NFS Server and Client: other-tools/nfs/nfs-server-client-setup.md
 theme:
     name: material
     custom_dir: nerc-theme