Green ssl certificate on local LAN - how to, without user intervention

[ARQ (Aurelian)]

1. Output of caddy version:

https://registry.hub.docker.com/_/caddy/

2. How I run Caddy:

I try to run it in a Synology DS1817+ over Docker.

a. System environment:

DSM 7.1.1-42962 Update 3 ; Docker 20.10.3-1308

b. Command:

c. Service/unit/compose file:

d. My complete Caddy config:

3. The problem I’m having:

I saw a short Youtube video a while ago that i could have my domain.office to show the Green valid Certificate instead of the warning most browsers show for the self signed certificate.

The idea is that i have an office with several departments and i need to be able to have like it.domain.office show properly once accessed. While the idea is nice and if i don’t need to install anything on any pc that would be perfect, it is little bit unclear what do i need to do.

The Synology i have it has 4 individual LAN ports that i can assign and program in order to have all the needed configs but no idea how to do the configs on Caddy i assume as reverse proxy in order to show proper certificate and don’t throw the warning on the browsers.

4. Error messages and/or full log output:

5. What I already tried:

6. Links to relevant resources:

[Matir (David)]

You either need to install your own private CA certificate on all of the clients accessing the server, or you need a valid domain and can set up a certificate using a real CA like Let’s Encrypt.

Since you say “without user intervention”, it seems like you’d need to go via the CA route. You could use your own domain and use DNS validation if the server is not publicly available. The Caddy documentation is actually excellent when it comes to this: Automatic HTTPS — Caddy Documentation