Unable to have https for localhost application

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1

1. Output of caddy version:

v2.6.2 h1:wKoFIxpmOJLGl3QXoo6PNbYvGW4xLEgo32GPBEjWL8o=

2. How I run Caddy:

I have installed caddy via sudo apt install caddy. Then I have started my Go application on localhost:8080. I have created Caddyfile with localhost and reverse_proxy but I still get untrusted site message when I visit the site. First i did run it with systemctl start/stop caddy and still untrusted. Then I run it with sudo caddy reverse_proxy --to localhost:8080 and get the same result.

a. System environment:

Linux Mint, systemctl

b. Command:

Paste command here.
systemctl start/stop caddy
sudo caddy reverse_proxy --to localhost:8080

c. Service/unit/compose file:

Paste full file contents here.
Make sure backticks stay on their own lines,
and the post looks nice in the preview pane. -->

d. My complete Caddy config:

localhost {
  reverse_proxy localhost:8080
}

3. The problem I’m having:

I am trying to proxy my GoLang application to have https.

4. Error messages and/or full log output:

2022/12/07 18:49:11.677	INFO	using provided configuration	{"config_file": "Caddyfile", "config_adapter": ""}
2022/12/07 18:49:11.678	WARN	Caddyfile input is not formatted; run the 'caddy fmt' command to fix inconsistencies	{"adapter": "caddyfile", "file": "Caddyfile", "line": 1}
2022/12/07 18:49:11.679	INFO	admin	admin endpoint started	{"address": "localhost:2019", "enforce_origin": false, "origins": ["//localhost:2019", "//[::1]:2019", "//127.0.0.1:2019"]}
2022/12/07 18:49:11.679	INFO	http	server is listening only on the HTTPS port but has no TLS connection policies; adding one to enable TLS	{"server_name": "srv0", "https_port": 443}
2022/12/07 18:49:11.679	INFO	http	enabling automatic HTTP->HTTPS redirects	{"server_name": "srv0"}
2022/12/07 18:49:11.679	INFO	tls.cache.maintenance	started background certificate maintenance	{"cache": "0xc0001faee0"}
2022/12/07 18:49:11.679	INFO	tls	cleaning storage unit	{"description": "FileStorage:/root/.local/share/caddy"}
2022/12/07 18:49:11.679	INFO	tls	finished cleaning storage units
2022/12/07 18:49:11.685	INFO	pki.ca.local	root certificate is already trusted by system	{"path": "storage:pki/authorities/local/root.crt"}
2022/12/07 18:49:11.685	INFO	http	enabling HTTP/3 listener	{"addr": ":443"}
2022/12/07 18:49:11.685	INFO	failed to sufficiently increase receive buffer size (was: 208 kiB, wanted: 2048 kiB, got: 416 kiB). See https://github.com/lucas-clemente/quic-go/wiki/UDP-Receive-Buffer-Size for details.
2022/12/07 18:49:11.685	INFO	http.log	server running	{"name": "srv0", "protocols": ["h1", "h2", "h3"]}
2022/12/07 18:49:11.685	INFO	http.log	server running	{"name": "remaining_auto_https_redirects", "protocols": ["h1", "h2", "h3"]}
2022/12/07 18:49:11.685	INFO	http	enabling automatic TLS certificate management	{"domains": ["localhost"]}
2022/12/07 18:49:11.685	WARN	tls	stapling OCSP	{"error": "no OCSP stapling for [localhost]: no OCSP server specified in certificate", "identifiers": ["localhost"]}
2022/12/07 18:49:11.685	INFO	autosaved config (load with --resume flag)	{"file": "/root/.config/caddy/autosave.json"}
2022/12/07 18:49:11.685	INFO	serving initial configuration
^X^C2022/12/07 18:50:19.337	INFO	shutting down	{"signal": "SIGINT"}
2022/12/07 18:50:19.337	WARN	exiting; byeee!! 👋	{"signal": "SIGINT"}
2022/12/07 18:50:19.339	INFO	tls.cache.maintenance	stopped background certificate maintenance	{"cache": "0xc0001faee0"}
2022/12/07 18:50:19.339	INFO	admin	stopped previous server	{"address": "localhost:2019"}
2022/12/07 18:50:19.339	INFO	shutdown complete	{"signal": "SIGINT", "exit_code": 0}

5. What I already tried:

Documentation and Youtube/Tiktok tutorials.

6. Links to relevant resources:

2

As you are not using a domain name, you can’t get a certificate from Let’sEncrypt or ZeroSSL so you need to use Caddy internal CA to issue certificates. You can enable it with the tls internal directive, something like this:

localhost {
  tls internal
  reverse_proxy localhost:8080
}
3

Thank you for your answer, I did add that ‘tls internal’ but it doesn’t work for me, still untrusted. Main problem is that I saw on Tiktok how guy use Caddy to have https for localhost. I tried everything I could find on the internet but no progress.

4

Self-signed (internal) certs won’t be trusted by clients on other systems unless they install trust for Caddy’s root.

@plorenzo Btw, tls internal is the default for localhost so that won’t make a difference and is unneeded there, actually. :slight_smile: I appreciate your help!!

5

Can you tell me how to do it or provide some references/links? thanks!

6

That totally depends on the OS/client accessing the server. I would start by google searching things like “how to add certificate to Linux Mint trust store” or “how to add cert to Firefox trust store”