CGI process current working directory

[kalvdans]

The README states:

The current working directory will be the same as Caddy itself.

But when testing, the CGI process's CWD is set to the directory containing the CGI script, not to Caddy's CWD.

Steps to reproduce

1. Create this directory structure:

/tmp/cgi-bug-report/
├── Caddyfile
└── subdir/
    └── test.sh

2. Create /tmp/cgi-bug-report/subdir/test.sh:

#!/bin/sh
printf "Content-type: text/plain\r\n\r\n"
printf "CWD: %s\n" "$(pwd)"

chmod +x /tmp/cgi-bug-report/subdir/test.sh

3. Create /tmp/cgi-bug-report/Caddyfile:

{
    debug
    auto_https disable_redirects
}

http://localhost:8080 {
    cgi / subdir/test.sh
}

4. Run caddy from /tmp/cgi-bug-report:

cd /tmp/cgi-bug-report && caddy run --config Caddyfile

5. curl http://localhost:8080/

Expected output

CWD should be /tmp/cgi-bug-report (Caddy's CWD).

Actual output

CWD: /tmp/cgi-bug-report/subdir

CWD is the script's directory, not Caddy's CWD.

Discussion

Adding dir . to the cgi block fixes it:

cgi / subdir/test.sh {
    dir .
}

Then output is:

CWD: /tmp/cgi-bug-report

I suggest that we fix the documentation to say that the cwd defaults to the script's directory, and that dir argument is relative to the cwd that caddy was started from.

Environment

• caddy-cgi v2.2.7
• Caddy v2.x
• Go 1.21+