SSL issue with Central on my internal network

I succeed installing central on my local machine with IP address on my LAN for testing purpose before deploying on my public server. I created a projetct, an app, an app user, upload form and media files and granted rights for the user.

I face a problem when i try to get the form list into collect.

Sale screen as here but I think for other reasons :

Is ther a way to disable ssl certification for lacal testing or a workaround to get a certiciate for my local server (without a domain name)

Thanks a lot

@issa gave me the following info a while back that could be useful?

Central requires HTTPS to be secure, and that it expects the following path structure:

  • https://…/* serves the frontend files. there is no frontend server; in the docker-compose setup we just leverage the nginx ssl terminator to also serve the static files.
  • https://…/v1/* is a proxy to the backend api. (the backend service will wish to see the /v1/ at root)

the backend expectations can be adjusted by proxy rewrites; the frontend may require more work depending on what you wish to set up.


If it's just for testing purposes, you'll probably love using ngrok as described in Testing ODK Collect with a Custom Server and Self Signed Certs and Authentication.


Hello @mathieubossaert.
Could you share a tutorial or image or a description of how to install Central Server .
Best regards.

Hi @famador, here is a link to the documentation with tutorials and guidance:


hello, unfortunately not. I just follow the documentation,
from here because docker is already installed on my machine :

But I am stuck on ssl issue on my local machine. I did not have time to test @LN and @danbjoseph proposals since she answered me.

so the problem you have here is that you are on a local (192.168..) IP address. this means that Let's Encrypt cannot provide a valid SSL certificate for you.

your options are:

  1. set up a local certificate authority that secures your development machine, and install that certificate on your android device (hard, time-consuming)
  2. mess with Central's code to remove HTTPS checks and run everything insecure (not hard, but dangerous)
  3. reinstall Central using a public domain name as suggested in the documentation, rather than use a local IP address

Thank @issa that's it.
As far as I understand, I can install Central without https and access/manage it with firefox.
The https problem only impact the connection between phone and server.
So I will manage form submission through usb.

I haven't installed through the Docker setup recently but I thought I could use ngrok for testing last time I did that. Is that not the case? Note that @mathieubossaert states he just wants to try things out locally before doing a real deployment.

You'll also find that certain Central actions aren't permitted such as downloading a submission CSV.

Maybe this post is relative to our deicsussion :