Connection issues with Mobile App on Android

ralfkrause

Two weeks ago I had a workshop with teachers for using the MoodleBox.

In my workshop concept I started with the MoodleBox and no internet connection. Yes, they also should try to connect with the Moodle app. No problem to connect and to view the cozrses.

After this first test with 15 really different devices I connected the MoodleBox to the internet and all devices could use the connection.

ralfkrause

A friend of mine asked me if the current Moodle app 3.9.5 will work together with the current MoodleBox 4.1.0.

For my tests I took my iPad Air 4. The iPad has no SIM card so there is no other way to the internet when it's connected with the MoodleBox. I deleted the Moodle app so all app settings are deleted, too. I restarted the iPad. I connected to the internet and installed the Moodle app again but I did not start the app.

I copied a fresh microSD card with the MoodleBox 4.1.0 image. Then I started this fresh MoodleBox an a Raspberry Pi 4B (4GB) which no ethernet connection. After a moment I could connect the iPad to the MoodleBox wifi. My system setting told me that there is no internet connection with the MoodleBox wifi.

In the next step I opened the url moodlebox.home in a web browser, got the start page, and logged in with the default moodlebox user. I added a new course with a forum and a folder. I uploaded some files into the folder. And I wrote a message with a photo into the forum. And I opened the MoodleBox dashboard to see the MoodleBox version and the connected devices. There was an iPad and no ethernet connection. The time setting was January 5th, 2022 ... the time when Nicolas produced the image.

Now I started the Moodle app ... no connection to the internet! I could connect to moodlebox.home and I could log in with the moodlebox user. I could see the start page and I could open the test course. I wrote a message into the forum and I loaded the files from the folder. I tested to download the compete course for offline learning. No problem!

In a next step I should test the same things in the Moodle app with an Android device. Perhaps there is a problem with Android and some coding in the app. I don't know if any library wants to connect to the internet before the app can be started.

ralfkrause

And now my frustrating results with Android

For my Android tablet I tried to do the same experiments as I did with the iPad. I deleted the Moodle app and restarted the tablet. Then I installed the Moodle app 3.9.5 from the Google Play Store again.

Now I switched to the MoodleBox wifi. The system tool told me that this wifi has no internet connection. The tablet got an ip address, the network mask and the router address. I started the web browser and opened the url moodlebox.home ... no problem. And I could also reach the start page with 10.0.0.1. I logged in and got all the things from the test course. In the MoodleBox dashboard I could see the correct ip addresses of the connected tablets ... the iPad and the Android tablet.

In the next step I started the Moodle app on the Android tablet. I got the url input but the app could not reach the url. I tried moodlebox, moodlebox/, moodlebox.home, moodlebox.home/, http://moodlebox.home, http://moodlebox.home/, 10.0.0.1, 10.0.0.1/. No connection in the Android Moodle app!

After a timeout of about 5 minutes I got the error message:"Cannot connect. We're having trouble connecting to your site. Please check the address is correct. 10.0.0.1/". The ip address is correct but there is no connection in the app.

No, I also got no connection with the ethernet cable connected to the router. It is frustrating! Could it be that the Android Moodle app does not work with Moodle sites which can be opened without https? Or is there a problem with the certificate?

I tested to connect some other Moodle sites with the Android Moodle app and I got no problem. But I could not connect to the MoodleBox.

Is this a hint to the problem? https://tracker.moodle.org/browse/MOBILE-3859

ralfkrause

Okay, I found a solution!

See https://docs.moodle.org/311/en/Moodle_app_guide_for_admins#Enable_mobile_services_on_your_site

For sites using https, mobile access is enabled by default in new installations of Moodle 3.0 onwards.
For http sites, mobile access can be enabled by an administrator as follows:
In Site administration > Mobile app > Mobile settings tick the 'Enable web services for mobile devices' checkbox
Click the button to save changes.
If your site uses a SSL certificate, it must be a trusted certificate. For security reasons the app doesn't work with self-signed certificates.

The Moodle app does not work with self-signed certificates. But the Moodle app works with web sites without https. To switch off https I edited the nginx configuration sudo nano /etc/nginx/sites-available/default

# Default server configuration
#
server {
        listen 80 default_server;
        listen [::]:80 default_server;

#       listen 443 ssl;
#       listen [::]:443 ssl;
#       ssl_certificate /etc/nginx/ssl/moodlebox.pem;
#       ssl_certificate_key /etc/nginx/ssl/moodlebox.key;

        root /var/www/moodle;

I set a comment sign # in front of every line with ssl and port 443.
After a reboot of the MoodleBox I can connect with the Android Moodle app. Great!

Yes, we will get other problems while modern browsers will show error messages for web sites without https.

Ian

ralfkrause Thank you so much for all your testing and advice. looking forward to trying this

Nicolas

ralfkrause This solution will be implemented in an upcoming version of MoodleBox image. See https://github.com/moodlebox/moodlebox/issues/271.

ralfkrause

And now I found the next thing.

If the MoodleBox https is switched off, any mobile device can connect, whether it is an iPhone, iPad or Android device. And once the mobile devices are connected to the MoodleBox, they seem to stay connected permanently even if https is switched back on.

In another test, I reactivated https in my MoodleBox. All of my mobile devices were still able to access the MoodleBox with the Moodle App and use the digital courses. There were no issues syncing data between the MoodleBox and the Moodle App.

Only when I delete my MoodleBox data in the Moodle app the connection gets lost and I can't log in again with Android because of the https problem. In this case I must temporarily switch off https on the MoodleBox to reconnect.

Since I assume that there are a lot of Moodle servers with self-signed certificates in the world, there should be a switch in the Moodle app to trust a self-signed certificate. The user of the digital device knows his teacher and his MoodleBox. He can trust both. The MoodleBox is not a server somewhere in the world offering its data.

Ralf

Nicolas

ralfkrause Since I assume that there are a lot of Moodle servers with self-signed certificates in the world, there should be a switch in the Moodle app to trust a self-signed certificate.

This is certainly true. I suggest you open an issue in the Moodle tracker for such a feature, which is not only a MoodleBox issue.

ralfkrause

There are some issue in the tracker about self-signed certificates and Android
https://tracker.moodle.org/browse/MOBILE-774
https://tracker.moodle.org/browse/MOBILE-3520
https://tracker.moodle.org/browse/MOBILE-3859
https://tracker.moodle.org/browse/MOBILE-3880

And there is a discussion in the community forum about MoodleBox and the Moodle app
https://moodle.org/mod/forum/discuss.php?d=424353

ralfkrause

I got an answer for this issue from Juan Leyva
https://tracker.moodle.org/browse/MOBILE-3859

Juan Leyva added a comment - 2 hours ago
Hi Ralf,

unfortunately, we cannot accept self-signed certificates in the app or provide a switch to enable them. Please see a detailed explanation here https://cordova.apache.org/docs/en/latest/guide/appdev/security/

What's the point of using a self-signed certificate in the MoodleBox for a local network? I'd suggest that in that case it would be just better to use HTTP

Regards, Juan

Ralf Krause added a comment - 1 minute ago
Hi Juan,

yes, the MoodleBox is a server device for a local network. The idea with the set-signed certificate is that modern browsers want to get https connections. In the case of http only some browsers are showing a red coloured "not secure" error in the address field or a not secure message before opening the website. If you import the self-signed certificate into your device you do not get those messages anymore. https://moodlebox.net/en/help/connexion-https/

But if we setup the MoodleBox to https with the self-signed certificate then we can't use the Moodle app.

Best regards, Ralf

ralfkrause

I did a new test with the new MoodleMox 4.2.0 and the current Moodle app 3.9.5.

The nginx configuration in the MoodleBox is prepared for https. The https settings were added for MoodleBox 3.5.0 in November, 2019. https://github.com/moodlebox/moodlebox/releases/tag/v3.5.0

In the Cordova community they are discussing a lot about problems with self-signed certificates. The Moodle app developers are using the Cordova framework and some official plugins. They do not take any unofficial plugin an do not patch anything in this framework. The document from Cordova will tell everything about self-signed certificates. https://cordova.apache.org/docs/en/latest/guide/appdev/security/#self-signed-certificates

With the fresh installed MoodleBox 4.2.0 version I tested the nginx configuration again. I did the same as I wrote in https://discuss.moodlebox.net/d/254-mobile-app/19. I commented out all lines with ssl inside. And I restarted the MoodleBox.

I connected the Moodle app on my Android tablet to http://moodlebox.home. I found some interesting facts. First I tested the connection with the MoodleBox 4.2.0 image without any change. The Moodle app needed 61 seconds to show the second screen where you enter the username and the password. This was just better than my test with the MoodleBox 4.1.0 image where I got a timeout after 3 or 4 minutes. After I commented out the ssl lines in the nginx configuration in 4.2.0 the Moodle app connected within only 1 second!

Changing the nginx configuration seems to be the best solution for the Moodle app problems with the MoodleBox.

Ratna

ralfkrause I don't see the problem. If Moodle Mobile App works on HTTP (no 'S') I would make an isolated MoodleBox deliver exactly that, HTTP. If the MoodleBox is on the Internet, I would make it deliver HTTPS. Where is the problem?

ralfkrause

Ratna
The problem is that the Android Moodle app does not connect to the MoodleBox 4.1.0 while ssl is switched on in the nginx configuration. This problem will be a frustrating experience for a lot of Android users. There is no problem with iOS.

With the updated Raspberry Pi OS the problem got a little bit smaller ... but waiting more than 60 seconds for the first connection is not useful. I must wait more than 60 seconds to connect to the MoodleBox 4.1.0 with the Raspberry Pi OS update. And I must wait the same more than 60 seconds to connect to the MoodleBox 4.2.0.

When I disabled ssl in the nginx configuration the same connection process only took 1 to 2 seconds for the Android Moodle app. So if your users should use the Android app then it would be a good idea to switch ssl off. The Moodle app 3.9.5 does not work with https (http with ssl) and a self-signed certificate.

ralfkrause

Now we got an answer from Juan Leyva for this problem. Juan is the main developer of the official Moodle app. He wrote that we should switch off https completely to use the MoodleBox together with the Moodle app.
https://moodle.org/mod/forum/discuss.php?d=424353#p1747266

Nicolas

ralfkrause I replied to the discussion for more info. Thanks for the heads up.

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