Tech review of Minecraft on OCI

Author: jasonrandrews

content/learning-paths/servers-and-cloud-computing/minecraft-on-oci/_index.md

@@ -18,9 +18,8 @@ learning_objectives:
     - Connect to the running Minecraft server from the Minecraft client application
 
 prerequisites:
-    - Review [Get started with Oracle Cloud Infrastructure](/learning-paths/servers-and-cloud-computing/csp/oci/) 
-    - Install software that allows you to connect to a running instance over SSH
-    - You will need a copy of the [Minecraft Java edition client](https://www.minecraft.net/en-us/download) installed, and [a license](https://www.minecraft.net/en-us/store/minecraft-java-bedrock-edition-pc) for the game
+    - An Oracle Cloud Infrastructure (OCI) account
+    - A copy of the [Minecraft Java edition client](https://www.minecraft.net/en-us/download) installed, and [a license](https://www.minecraft.net/en-us/store/minecraft-java-bedrock-edition-pc) for the game
 
 author: Dave Neary
 

content/learning-paths/servers-and-cloud-computing/minecraft-on-oci/configuring_new_minecraft_server.png

@@ -7,64 +7,73 @@ weight: 4
 layout: learningpathall
 ---
 
-## Connecting the Minecraft client to the server
+## Connect the Minecraft client to the server
 
 ### Opening the port for the Minecraft server
 
-Before you connect to the Minecraft server, you will change the network policy to allow clients
-to connect to the Minecraft server over TCP port number 25565. To do this, you need to modify
-the networking settings for your instance in the OCI dashboard.
+Before you connect to the Minecraft server, change the network policy to allow clients to connect to the Minecraft server over TCP port number 25565. To do this, you need to modify the networking settings for your instance in the OCI dashboard.
 
 1. On the OCI Instances page, choose your Minecraft server instance.
 2. In the **Networking** tab, click on the subnet name:
-   ![OCI Networking panel displaying instance subnet configurations#center](oci_instance_networking.png "Open the networking panel in OCI")
+   ![OCI Networking panel displaying instance subnet configurations#center](oci_instance_networking.webp "Open the networking panel in OCI")
 3. On the **Security** tab of the subnet page, choose the security list which is active for the instance
    (by default, this is called "Default Security List for vcn-xxxxxxxx")
-   ![OCI Subnet Details page highlighting the Default Security List#center](subnet_security_list.png "Select the Default Security List on the Subnet Details page")
+   ![OCI Subnet Details page highlighting the Default Security List#center](subnet_security_list.webp "Select the Default Security List on the Subnet Details page")
 4. Under **Security rules**, add a new Ingress rule (this means the rule applies to incoming traffic
-   from outside the instance). Set **Source CIDR** to "0.0.0.0/0" (this means all IP addresses can
-   connect), and set the **Destination Port Range** field to 25565.
-   ![OCI Ingress Rules dialog with source CIDR 0.0.0.0/0 and destination port 25565#center](open_minecraft_port.png "Configure an Ingress rule to open port 25565")
+   from outside the instance). Set **Source CIDR** to the public IP address (or range) of the
+   players who will connect to your server. For example, if your home IP address is `203.0.113.45`,
+   set the Source CIDR to `203.0.113.45/32` to allow only that address. You can add multiple
+   ingress rules if players connect from different networks.
 
-You will also need to update the instance's local firewall to allow connections to port 25565 on 
-your instance. Reconnect to your instance with SSH, and run the following commands:
-```
+   {{% notice Warning %}}
+   Avoid using `0.0.0.0/0` as the Source CIDR. This opens the port to the entire internet and
+   exposes your server to unauthorized access attempts. Always restrict access to only the IP
+   addresses that need to connect.
+   {{% /notice %}}
+
+   Set the **Destination Port Range** field to 25565.
+   ![OCI Ingress Rules dialog with source CIDR and destination port #center](open_minecraft_port.webp "Configure an Ingress rule to open port 25565")
+
+   You can find your current public IP address by searching "what is my IP address" in a web browser
+   from the network you will use to connect.
+
+You will also need to update the instance's local firewall to allow connections to port 25565 on your instance. Run the following commands:
+
+```console
 sudo firewall-cmd --permanent --add-port=25565/tcp
 sudo firewall-cmd --reload
 ```
 
-You should now be able to run your Minecraft server on the OCI instance, then start your client
-on your laptop or desktop., You will first be asked to log in with your Microsoft or Mojang account.
+You should now be able to run your Minecraft server on the OCI instance, then start your client on your laptop or desktop. You will first be asked to log in with your Microsoft or Mojang account.
+
 Use the credentials you created for your Microsoft account.
 
 ### Connecting to the server from the Minecraft client
 
 1. Before connecting to the server with the client for the first time, you will need to
-[register for a Microsoft account](https://www.minecraft.net/en-us/download).
+[register for a Microsoft account](https://signup.live.com/).
 2. Start your Minecraft client and log in with your Microsoft account credentials.
 3. Start the "Minecraft Java edition" client from the launcher.
-   ![Minecraft launcher screen](minecraft_launcher.png)
+   ![Minecraft launcher screen](minecraft_launcher.webp)
 4. Choose **Multiplayer** mode - read and click through the warning that third party servers are not operated by Mojang.
 5. To add your server to the menu of available servers, choose **Add server**, name your server
 something meaningful ("My OCI server" for example) and put the IP address of your instance into the
 **Server Address** field:
-   ![Minecraft multiplayer server dialog showing Server Name and Server Address fields filled in#center](configuring_new_minecraft_server.png "Add your OCI instance public IP address to the Server Address field")
+   ![Minecraft multiplayer server dialog showing Server Name and Server Address fields filled in#center](configuring_new_minecraft_server.webp "Add your OCI instance public IP address to the Server Address field")
 
 You can now join the server and start building!
 
-![Minecraft game client showing successful connection to the custom multiplayer server#center](connecting_to_server.png "Connect to the custom Minecraft server")
+![Minecraft game client showing successful connection to the custom multiplayer server#center](connecting_to_server.webp "Connect to the custom Minecraft server")
 
 ### What you've accomplished
 
 In this guide, you successfully:
+
 - Provisioned an Arm-based VM instance on Oracle Cloud Infrastructure.
 - Installed Java and deployed the Minecraft server software.
 - Configured OCI security ingress rules and server-side firewalls to expose the port.
 - Added and connected to the server using the Minecraft client application.
 
 ### Next steps
 
-Now that your server is running, you can share the IP address with friends for multiplayer play. You can also explore automated startup scripts to ensure the server automatically recovers from reboots.
-
-
-
+Now that your server is running, you can share the IP address with friends for multiplayer play. You can also explore automated startup scripts to ensure the server automatically recovers from reboots.

content/learning-paths/servers-and-cloud-computing/minecraft-on-oci/configuring_new_minecraft_server.webp

@@ -11,43 +11,56 @@ layout: learningpathall
 
 ### Installing the Java Runtime Environment
 
-Before you install the Minecraft server, you need to make sure that there are some prerequisites
-installed. For the Minecraft 26 server or earlier, you will need Java 25.
+Before you install the Minecraft server, you need to install the required software. For the Minecraft 26 server or earlier, you will need Java 25.
 
-Connect to your instance using SSH as described in the previous step. You can install Java 25 on
-Oracle Linux with:
+Connect to your instance using SSH as described in the previous step. You can install Java 25 on Oracle Linux 9 with:
 
 ```console
-sudo dnf install java-25-openjdk -y
+sudo dnf install java-25-openjdk.aarch64 -y
 ```
 
-and on Ubuntu or similar distributions, with
+### Keeping the server running after disconnecting
+
+The Minecraft server runs in the foreground of your terminal session. If you close your SSH
+connection, the server process will stop. To keep the server running after you disconnect, use
+`tmux` to create a persistent terminal session.
+
+While still connected to your instance via SSH, install `tmux` on Oracle Linux 9:
 
 ```console
-sudo apt install openjdk-25-jre -y
+sudo dnf install tmux -y
 ```
 
-Since the Minecraft server starts on the command line, you might also want to install the `screen` or
-`tmux` utilities which allows commands to keep running after you disconnect from the server.
-These commands are not strictly necessary, but you will need them to be running if you want to keep
-the server running when you disconnect from your SSH session. 
+Start a new `tmux` session named "minecraft":
+
+```console
+tmux new -s minecraft
+```
 
-Running the Minecraft server at start-up, or keeping it running when you are not connected, will
-not be covered in this learning path.
+You are now inside a `tmux` session. Any commands you run here will continue running even after you
+disconnect from SSH. You will start the Minecraft server inside this session in the next section.
+
+When you need to disconnect, press `Ctrl+B` then `D` to detach from the session. The server
+continues running in the background.
+
+To reattach to the session later (for example, after reconnecting via SSH):
+
+```console
+tmux attach -t minecraft
+```
 
 ### Downloading and installing the Minecraft server
 
 You can find the link for the latest version of the Minecraft server
-[on the Minecraft website](https://www.minecraft.net/en-us/download/server). Copy the link to
-`server.jar` from this page, and run the following command on your OCI instance to download it:
+[on the Minecraft website](https://www.minecraft.net/en-us/download/server). 
+
+On that page, right-click the `minecraft_server.x.x.x.jar` link and copy the URL. Then run the following command on your OCI instance to download it:
 
 ```console
 wget <paste URL to server.jar here>
 ```
 
-This will download `server.jar` from the Mojang website, and you will have a `server.jar` file on your OCI
-instance. To make it easier to keep track of different server versions, rename the `server.jar` file
-with a more meaningful name: 
+This will download `server.jar` from the Mojang website, and you will have a `server.jar` file on your OCI instance. To make it easier to keep track of different server versions, rename the `server.jar` file to a more meaningful name:
 
 ```console
 mv server.jar minecraft_server.26.2.jar
@@ -59,17 +72,21 @@ To start the Minecraft server, run the command:
 java -Xmx8G -Xms8G -jar minecraft_server.26.2.jar nogui
 ```
 
-This runs the server withough a graphical user interface, and allocates 8GB of memory to it. If you
-allocated less than this amount of memory to your instance, set this number to 3/4 of the memory that
-you allocated to the instance - the other operating system services need some memory too.
+This runs the server without a graphical user interface, and allocates 8GB of memory to it.
+
+The first time you do this, the start-up will fail and a file called `eula.txt` is created in the local folder. 
 
-The first time you do this, the start-up will fail expectedly - a file called `eula.txt` is created
-in the local folder, and before you start the server, you first need to accept its terms of use. Open
-this file and follow the instructions to accept the terms and conditions. Running the server again
-after doing this will succeed, and you should see the following messages on the terminal, showing
-that the process has completed successfully (timestamps will be different at the start of the lines):
+Before you start the server, you first need to accept its terms of use. 
 
+Open `eula.txt` and change `eula=false` to `eula=true`, or run:
+
+```console
+sed -i 's/eula=false/eula=true/' eula.txt
 ```
+
+Running the server again after doing this will succeed, and you should see the following messages on the terminal, showing that the process has completed successfully (timestamps will be different at the start of the lines):
+
+```output
 [00:40:50] [Server thread/INFO]: Starting minecraft server version 26.2
 [00:40:50] [Server thread/INFO]: Loading properties
 [00:40:50] [Server thread/INFO]: Default game type: SURVIVAL
@@ -96,6 +113,4 @@ You installed the open-source Java Runtime Environment on your instance, downloa
 
 ### Next step
 
-With the server successfully running in the cloud, you will now open the necessary network ports to allow the Minecraft client to connect to your instance.
-
-
+With the server successfully running in the cloud, you will now open the necessary network ports to allow the Minecraft client to connect to your instance.

content/learning-paths/servers-and-cloud-computing/minecraft-on-oci/connecting_to_server.png

@@ -7,22 +7,23 @@ weight: 2
 layout: learningpathall
 ---
 
-## Starting an OCI A4 or A1 instance
+## Starting an OCI A1 instance
 
-Once you have [created an OCI account](/learning-paths/servers-and-cloud-computing/csp/oci/)
-and verified that you can start an instance, you will create an Ampere powered A1 instance
-and connect to it with SSH to install the Minecraft Java server.
+Make sure you have an OCI account. If you need to create an account refer to
+[Getting Started with Oracle OCI](/learning-paths/servers-and-cloud-computing/csp/oci/).
+
+Next, create an Ampere powered A1 instance and connect with SSH.
 
 1. Log on to [Oracle Cloud](https://cloud.oracle.com)
 2. On the OCI dashboard, navigate to Compute -> Instances to start a new instance: 
-   ![OCI Console Compute dashboard showing the Instances section#center](oci_compute_dashboard.png "Navigate to Compute -> Instances in the OCI dashboard")
+   ![OCI Console Compute dashboard showing the Instances section#center](oci_compute_dashboard.webp "Navigate to Compute -> Instances in the OCI dashboard")
 3. Click "Create instance", then: 
     * Choose one of the availability domains offered to you with A1 instances available
     * Select "Change shape", and set the instance type to Ampere VM.Standard.A1.Flex:
-      ![OCI instance creation shape settings panel with VM.Standard.A4.Flex selected#center](oci_change_shape.png "Configure the VM instance shape to VM.Standard.A4.Flex")
+      ![OCI instance creation shape settings panel with VM.Standard.A1.Flex selected#center](oci_change_shape.webp "Configure the VM instance shape to VM.Standard.A1.Flex")
     * Beside the instance type, click the small black arrow to open options. Allocate 2 OCPUs
       and 12 GB of memory to your instance
-    * Choose "Oracle Linux 9" or one of the other available images of your choice under "Change
+    * Choose "Oracle Linux 9" under "Change
       image", then click Next
 4. Use the default security options, click "Next" to get to networking options
 5. Configure networking as follows:
@@ -33,20 +34,21 @@ and connect to it with SSH to install the Minecraft Java server.
     * Create an SSH key pair if you do not have one (and download both private and public keys),
       or upload the public key for an existing key pair so that you can connect to your instance
       over SSH once it is created
-5. Use default Storage options
-6. After verifying that the instance is correctly configured, choose "Create" to provision a new 
+6. Use default Storage options
+7. After verifying that the instance is correctly configured, choose "Create" to provision a new 
    instance
-7. It can take up to 2 minutes for your instance to be created. Once created, you need to ensure
+8. It can take up to 2 minutes for your instance to be created. Once created, you need to ensure
    that there is a public IP address to connect to by going to the "Networking" tab for the instance:
-   ![Instance details page with the Networking tab selected to show public IP details#center](oci_instance_networking.png "Select the Networking tab on your VM details page")
-8. Scroll down and click on the VNIC name - `instance-yyyymmdd-HHmm` by default - then on the IP
-   administration tab, and click on the three dots on the primary IP row to edit the IP address type
-   associated with the instance to set its type to "Ephemeral public IP":
-   ![OCI IP management page showing primary private IP and ephemeral public IP configurations#center](oci_network_ip_management.png "Edit IP Address to set type to Ephemeral public IP")
-
-Take note of the IP address under "Public IP address". You should now be able to SSH into your
-instance with the command
-```
+   ![Instance details page with the Networking tab selected to show public IP details#center](oci_instance_networking.webp "Select the Networking tab on your VM details page")
+9. If you did not select "Automatically assign public IPv4 address" during instance creation, you
+   will need to assign one manually. Scroll down and click on the VNIC name - `instance-yyyymmdd-HHmm`
+   by default - then on the IP administration tab, and click on the three dots on the primary IP row
+   to edit the IP address type associated with the instance to set its type to "Ephemeral public IP":
+   ![OCI IP management page showing primary private IP and ephemeral public IP configurations#center](oci_network_ip_management.webp "Edit IP Address to set type to Ephemeral public IP")
+
+Take note of the IP address under "Public IP address". You should now be able to SSH into your instance with the command:
+
+```console
 ssh -i <path to private key> opc@<public IP address>
 ```
 
@@ -56,4 +58,4 @@ You successfully provisioned an Ampere A1 virtual machine instance on Oracle Clo
 
 ### Next step
 
-Now that your VM is running and accessible, you will proceed to install Java and download the Minecraft server software.
+Now that your VM is running and accessible, proceed to install Java and download the Minecraft server software.