Recently with music-streaming services like Spotify and YouTube Music getting popular, one may ask whether it’s possible to setup personal music-streaming service. The answer is yes.
There is a solution called Subsonic, which is developed by Sindre Mehus. However, Subsonic is no longer open source after 2016. Hence, we would talk about another open-source project inspired by Subsonic, i.e. Airsonic. According the the official website, the goal of Airsonic is to provide a full-featured, stable, self-hosted media server based on the Subsonic codebase that is free, open source, and community driven. So, let’s see how we can get Airsonic up and running on Azure.
Ubuntu on Microsoft Azure
Azure Virtual Machines supports running Linux and Windows. Airsonic can be installed on both Linux and Windows too. Since Linux is an open-source software server, it will be cheaper to run it on Azure than a Windows server.
Currently, Azure supports common Linux distributions including Ubuntu, CentOS, Debian, Red Hat, SUSE. Here, we would choose to use Ubuntu because it certainly has the upper hand when it comes to documentation and online help which makes finding OS-related solutions to easy. In addition, Ubuntu is updated frequently with LTS (Long Term Support) version released once every two years. Finally, if you are users of Debian-style distributions, Ubuntu will be a comfortable pick.
Azure VM Size, Disk Size, and Cost
We should deploy a VM that provides the necessary performance for the workload at hand.
The B-series VMs are ideal for workloads that do not need the full performance of the CPU continuously. Hence, things like web servers, small databases, and our current project Airsonic is a suitable use case for B-series VMs. Hence, we will go for B1s which has only 1 virtual CPU and 1GiB of RAM. We don’t choose B1ls which has the smallest memory and lowest cost among Azure VM instances is because the installation of Airsonic on B1ls is found to be not successful. The lowest we can go is only B1s.
For the OS disk type, instead of the default Premium SSD option, we will go for Standard SSD because it is not only a lower-cost SSD offering, but also more suitable for our audio application which is lightly used.
Remove Public Inbound Ports and Public IP Address
It’s not alright to have SSH port exposed to the Internet because there will be SSH attacks. Hence, we will remove the default public inbound ports. This will make all traffic from the Internet will be blocked. Later we will need to use a VPN connection instead to connect to the VM.
By default, when we create a VM on Azure Portal, there will be a public IP address given. It’s always recommended to not have public IP bound to the VM directly even there is only a single VM. Instead, we should deploy a load balancer in front of the VM and then have the VM bound to the load balancer. This will eventually make our life easier when we want to scale out our VM.
To not have any public IP address assigned to the VM, as shown in the screenshot below, we need to change the value of Public IP to “None”.
Setup Virtual Network and VPN Gateway
When we create an Azure VM, we must create a Virtual Network (VNet) or use an existing VNet. A VNet is a virtual, isolated portion of the Azure public network. A VNet can then be further segmented into one or more subnets.
It is important to plan how our VM is intended to be accessed on the VNet before creating the actual VM.
Since we have removed all the inbound public ports for the VM, we need to communicate with the VM through VPN. Hence, we currently need to have at least two subnets where one is for the VM and another one is for the VPN Gateway. We will add the subnet for VPN Gateway later. Now, we just do as follows.
Setup Point-to-Site (P2S) VPN Connection
There are already many tutorials available online about how to setup P2S VPN on Azure, for example the one written by Dishan Francis in Microsoft Tech Community, so I will not talk about how to setup the VPN Gateway on Azure. Instead, I’d like to highlight that P2S Connection is not configurable on Azure Portal if you are choosing the Basic type of the Azure VPN Gateway.
Once the VM deployment is successful, we can head to where the VNet it is located at. Then, we add the VPN Gateway subnet as shown in the screenshot below. As you can see, unlike the other subnets, the Gateway Subnet entry always has its name fixed to “GatewaySubnet” which we cannot modify.
Next, we create a VPN Gateway. Since we are using the gateway for P2S, the type of VPN needs to be route-based. The gateway SKU that we chose here is the lowest cost, which is VpnGw1. Meanwhile, the Subnet field will be automatically chosen once we specify our VNet.
The VPN gateway deployment process takes about 25 minutes. So while waiting for it to complete, we can proceed to create self-sign root and client certificates. Only root cert will be used in setting up the VPN Gateway here. The client certificate is used for installation on other computers which need P2S connections.
Once the VPN gateway is successfully deployed, we will then submit the root cert data to configure P2S, as shown below. In the Address pool field, I simply use 10.4.0.0/24 as the private IP address range that I want to use. VPN clients will dynamically receive an IP address from the range that we specify here.
Now, we can download the corresponding VPN client to our local machine and install it. With this, we will get to see a new connection having our resource group name as its name available as one of the VPN connections on our machine.
We can then connect to our VM using its private IP address, as shown in the screenshot below. Now, at least our VM is secured in the sense that its SSH port is not exposed to the public Internet.
Upgrade Ubuntu to 20.04 LTS
Once we have successfully connected to our VM, if we are using the Ubuntu 18.04 provided on Azure, then we will notice a message reminding us that there is a newer LTS version of Ubuntu available, which is Ubuntu 20.04, as shown in the screenshot below. Simply proceed to upgrade it.
Set VM Operating Hours
Since in cloud computing, we pay for what we use. Hence, it’s important that our VMs are only running when it’s necessary. If the VM doesn’t need to run 24-hour everyday, then we can configure its auto start and stop timings. For my case, I don’t listen to music when I am sleeping, so I will turn off the audio server between 12am to 6am.
To start and stop our VM at a scheduled time of the day, we can use the Tasks function, which is still in preview and available under Automation section of the VM. It will create two Logic Apps which will not automatically start or stop the VM.
Instead, I have to change the Logic Apps to send HTTP POST requests to start and powerOff endpoints of Azure directly, as suggested by R:\ob.ert in his post “Start/Stop Azure VMs during off-hours — The Logic App Solution”.
Install Airsonic and Run as Standalone Programme
Since our VM will be automatically stopped and started everyday, it’s better to integrate Airsonic programme with Systemd so that Airsonic will be automatically run on each boot. There is a tutorial on how to set this up in the Airsonic documentation, so I will not describe the steps here. However, please remember to install Open JDK 8 too because Airsonic is based on Java to run.
By default, Airsonic will be available at the port 8080 and it is listening on the path /airsonic. If the installation is successful, with our VPN connection connected, then we shall be able to see the following login screen in our first visit. Please immediately change the password as instructed for security purpose.
Public IP on VM Only via Load Balancer
We need to allow Airsonic music streaming over the public Internet and thus the VM needs to be accessible via public IP. However, since we have already earlier configured our VM to not have any public IP address, there needs to be a public load balancer bound to the VM. This setup gives us the flexibility to change the VM in the backend on the fly and secure the VM from Internet traffic.
Now, we can create a public load balancer, as shown in the screenshot below. The reason why Basic SKU which has no SLA is used here is because it’s free. SLA is optional to me here because this VM will be just a personal audio server.
Basic SKU public IP address supports a dynamic as the default IP address assignment method. This means that a public IP address will be released from a resource when the resource is stopped (or deleted). The same resource will receive a different public IP address on start-up next time. If this is not what you expect, you can choose to use a static IP address to ensure it remains the same.
We now need to attach our VM to the backend pool of the load balancer, as shown in the following screenshot.
After that, in order to allow Airsonic to be accessible from the public Internet, we shall set an inbound NAT (Network Address Translation) rule on the Azure Load Balancer. Here since I have only one VM, I directly set the VM as the target and setup a custom port mapping from port 80 to port 8080 (8080 is the default port used by Airsonic), as shown below.
Also, at the same time, we need to allow port 8080 in the Network Interface of the VM, as highlighted in the screenshot below.
Note: The VM airsonic-main-02 shown in the screenshot is the 2nd VM that I have for the same project. It is same as airsonic-main VM.
Once we have done all these, we can finally access Airsonic through the public IP address of the load balancer.
Enjoy the Music
By default, the media folder that will be used by Airsonic is at /var/music, as shown below. If this music folder does not exist yet, simply proceed to create one.
By default, the media folder is not accessible by any of the users. We need to explicitly give users the access to the media folders, as shown in the screenshot below.
As recommended by Airsonic, the music folders we add to /var/music and other media folders are better organized in an “artist/album/song” manner. This will help Airsonic to automatically build the albums. In addition, since I have already entered the relevant properties such as title and artist name to the music files, so Airsonic can read them and display on the web app, as shown in the screenshot below.
In addition, both Airsonic and Subsonic provide the same API. Hence, we can access our music on Airsonic through Subsonic mobile apps as well. Currently I am using the free app Subsonic Music Streamer on my Android phone and it works pretty well.
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