Error: reading default Caddyfile: open Caddyfile: permission denied

[AlanQ (Alan)]

Very first try with Caddy.
Installed as a snap on Lubuntu 24.04
I’m following the Quick Start instructions at Caddyfile Quick-start

1. The problem I’m having:

As per the instructions, I have created /home/alan/DEV/caddy/Caddyfile
Caddyfile contains only this:

{
        debug
}

localhost

respond "Hello, world!"

I get an error message when I run $ sudo caddy start while inside /home/alan/DEV/caddy/

2. Error messages and/or full log output:

$ sudo caddy start
+ id -u
+ [ 0 = 0 ]
+ _caddy=/snap/caddy/673/usr/bin/caddy
+ snapctl get modified
+ [  = true ]
+ cli start
+ arg=start
+ shift 1
+ /snap/caddy/673/usr/bin/caddy start
2025/11/26 19:22:00.948 WARN    failed to set GOMAXPROCS        {"error": "open /proc/self/mountinfo: permission denied"}
2025/11/26 19:22:00.948 INFO    GOMEMLIMIT is updated   {"package": "github.com/KimMachineGun/automemlimit/memlimit", "GOMEMLIMIT": 7679873433, "previous": 9223372036854775807}
2025/11/26 19:22:00.948 INFO    maxprocs: No GOMAXPROCS change to reset
Error: reading default Caddyfile: open Caddyfile: permission denied
Error: caddy process exited with error: exit status 1

journalctl -u caddy --no-pager | less +G
shows

– No entries –

3. Caddy version:

$ sudo caddy version
+ id -u
+ [ 0 = 0 ]
+ _caddy=/snap/caddy/673/usr/bin/caddy
+ snapctl get modified
+ [  = true ]
+ cli version
+ arg=version
+ shift 1
+ /snap/caddy/673/usr/bin/caddy version
551f793700fe1550845c824470b623fd1aa03d36 (22 Aug 25 21:29 UTC)

4. How I installed and ran Caddy:

a. System environment:

$ uname -a
Linux L24 6.14.0-33-generic #33~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Fri Sep 19 17:02:30 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

$ systemd --version
systemd 255 (255.4-1ubuntu8.11)
+PAM +AUDIT +SELINUX +APPARMOR +IMA +SMACK +SECCOMP +GCRYPT -GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS +FIDO2 +IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 -PWQUALITY +P11KIT +QRENCODE +TPM2 +BZIP2 +LZ4 +XZ +ZLIB +ZSTD -BPF_FRAMEWORK -XKBCOMMON +UTMP +SYSVINIT default-hierarchy=unified 

$ snap --version
snap          2.72
snapd         2.72
series        16
ubuntu        24.04
kernel        6.14.0-33-generic
architecture  amd64

b. Command:

$ sudo caddy start

c. Service/unit/compose file:

d. My complete Caddy config:

{
        debug
}

localhost

respond "Hello, world!"

$ ll
total 12
drwxrwxr-x 2 alan alan 4096 Nov 26 19:21 ./
drwxrwxr-x 5 alan alan 4096 Nov 26 18:47 ../
-rw-rw-r-- 1 alan alan   47 Nov 26 19:21 Caddyfile

I have tried changing the permissions of Caddyfile to rwxrwxrwx, but it makes no difference.

5. Links to relevant resources:

Caddyfile Quick-start — Caddy Documentation

[francislavoie]

You have a snap version of Caddy installed, and snaps have limited permission to read files on your system. Don’t use the snap. That’s not an official installation method.

Install - Caddy Documentation

The quick start isn’t quite representative of how you should run Caddy normally, it’s more of a tour of Caddy. See Keep Caddy Running — Caddy Documentation.

[AlanQ (Alan)]

Thank you, Francis

I have removed the snap and installed caddy from my apt repository.

Now I get a different error:

$ caddy start
2025/11/29 14:17:25.966 INFO    using adjacent Caddyfile
Error: loading initial config: loading new config: starting caddy administration endpoint: listen tcp 127.0.0.1:2019: bind: address already in use
Error: caddy process exited with error: exit status 1

I’m reading the docs…

[francislavoie]

You didn’t stop your other Caddy process. Also stop using caddy start, it doesn’t let you see logs. Run Caddy as a systemd service.

[AlanQ (Alan)]

Thank you again, Francis

As a developer I was simply looking for a quick and easy way to get an https server up for testing.

I shall persevere for now, but perhaps ultimately I should look elsewhere…?

[francislavoie]

But it is quick and easy. Just follow the docs at the links I gave you. Uninstall the Caddy you got from snap, then install Caddy from our apt repo, then put your Caddyfile in /etc/caddy/Caddyfile, then reload the config with sudo systemctl reload caddy. That’s all you need to get up and running.

[AlanQ (Alan)]

A final thank you, Francis, I’m almost there…