You are currently viewing Synology – ChangeDetection on your NAS with Docker in 5 minutes – Cachem

Synology – ChangeDetection on your NAS with Docker in 5 minutes – Cachem

ChangeDetection.io is a web page change tracking system. The tool is free, open source and it is even possible to self-host on your NAS. It’s an interesting alternative to Visualping or Watchtower if you know. Today, I offer you this tutorial to install and configure it on your Synology NAS with Docker.

ChangeDetection and Synology

ChangeDetection.io is an easy to use service in monitoring and detecting website changes. When it detects a change during its monitoring, the tool will be able to notify you through the services of your choice: e-mail, SMS, Discord, Slack, Gotify, Kodi, etc. For this, it is based on the excellent Apprise system! ChangeDetection.io is completely free and it can work self-hosted. It works in Python and you will find a lot of information on the official site.

ChangeDetection and Docker

If you use Docker on your NAS, you will see that it is very easy to install and configure. If you have a Synology Docker-enabled box, it’s very simple. In 5 minutes, it will be functional!

Install ChangeDetection

The first step is to upload the image togtlmoon/changedetection.io and for that, just launch the Docker application on the NAS. Then click on Register in the left menu. render in type changedetection in the search box at the top right (see image below). Then, you double-click on the first link, being careful that it is the image dgtlmoon/changedetection.io.

changedetection docker - Synology - ChangeDetection on your NAS with Docker in 5 minutes

As usual, you will get the small dialog box to download the latest version of the image (choice Latest).

image latest docker synology - Synology - ChangeDetection on your NAS with Docker in 5 minutes

You wait a few seconds for the image to download. You can check its progress in the left menu Image. Once the download is complete, double click on it to start creating the container. You can leave the default values ​​(bridge like the picture below) and you click on the button Next

synology container bridge - Synology - ChangeDetection on your NAS with Docker in 5 minutes

In the general settings, you’ll enter a name for your container. You can also set the resources by setting the processor priority to Low (it’s not a critical or important resource) and you can decrease the use of RAM (I put 128 MB).

Creation changedetection 01 1 - Synology - ChangeDetection on your NAS with Docker in 5 minutes

You click the button Next. For the port setting (there is only one here), I recommend that you choose an unused port such as 5075 as the local port and leave 5000 for the container port (see image below). below).

change docker port - Synology - ChangeDetection on your NAS with Docker in 5 minutes

We continue by pressing the button Next. We will now add a working folder for Change Detection.

changedetection folder - Synology - ChangeDetection on your NAS with Docker in 5 minutes

We click on the button Add Folder. You move to the docker folder of your NAS and you click on the button Create a folder. Here, my file is named ChangeDetection (no, it’s not very original). We press the button OK then Select and finally Next.

datastore - Synology - ChangeDetection on your NAS with Docker in 5 minutes

In the path zone, we indicate /datastore (see image above) and press the button Next.

summary docker changedetection - Synology - ChangeDetection on your NAS with Docker in 5 minutes

Small summary screen and all you have to do is press the button Carried out. It’s over for the installation part. On the second part of the article, we are going to start our site monitoring, configure the frequency of verification and finally generate an alert as soon as a change is detected by the tool.

Monitor a site with ChangeDetection

In your favorite browser, type the IP address of your NAS followed by port 5075 (if you did the same as me). You should have something like 192.168.1.100:5075 to type. Once you have validated, you should have this page.

changedetection end - Synology - ChangeDetection on your NAS with Docker in 5 minutes

You will notice that the interface is only in English. To date, it is not possible to change it to French. By default, there are already 3 monitored sites. The first 2 (on the capture) will be used to test the tool and the notifications. The latter monitors the changelog on the changedetection.io site. It will allow to be alerted when an update is available.

docker synology 100x100 - Synology - ChangeDetection on your NAS with Docker in 5 minutes Update your Docker container on Synology

To add the detection of a site, it’s quite simple. In the section “Add a new change detection watch” you indicate in the left part the name of the site, for example https://www.cert.ssi.gouv.fr/ (as soon as a security breach is detected) and on the right part the group in which the site must be classified (e.g.: Cybersecurity). If the group does not exist, it will create automatically. This then makes it possible to classify in a view all the sites of the same type (tabs). Once you press the button Watchthis site will be monitored.

ChangeDetection Settings

Now let’s go to the menu SETTINGS top right. On the first tab, this is where you make the default settings. As you can see here, the tool will do a change analysis every 3 hours. It is of course possible to change (weeks, days, hours, minutes, seconds). This setting will be general to all sites you enter. Note that it is possible to modify the parameters for each monitored site from the main page (Edit button in front of each of the sites). But here we are on the default settings for the whole system. Be careful not to do too much daily analysis of the same site, the administrator could decide to ban you.

general changedetection - Synology - ChangeDetection on your NAS with Docker in 5 minutes

There are other parameters here on this page that I let you discover…

Notifications with ChangeDetection

tab Notifications will allow them to be configured. Detecting a change on a site is good… being alerted when it does is even better. As stated earlier, ChangeDetection embeds Apprise’s notification system. It is absolutely necessary to go through this site to find the necessary information.

changedetection notifications - Synology - ChangeDetection on your NAS with Docker in 5 minutes

As I like to use emails, here is the expression I used for Infomaniak:
mailtos://NomUtilisateur:[email protected]?smtp=mail.infomaniak.com&[email protected]
If like me you use special characters in your password, you will have to put them in Hexadecimal. It’s not terrible, but we have no choice. Some examples :

ASCII character HEX Match
# %23
$ %24
& %26
e %e9
+ %2b
%2d

If your password is: 4Tynqh+c3# it will become 4Tynqh%2bc3%23

Don’t forget to save and then press the button Send test notification to test that you receive a notification. If you do not receive well, you can consult the errors via the button Debug log notification. This was helpful for me to figure out for my password was not working 😉 Still on tab Notificationsyou can customize the message you will receive when a change is detected (notification title, message body, format, etc.).

Well, this tutorial is coming to an end. The tool ChangeDetection is simple and effective. If you have any questions or want to share your experience…feel free to use the comments below.

Thank you Guillaume for the discovery