caddy fmt will silently ignore all but the first file path passed to it

[alexwlchan]

If you call caddy fmt with the path to more than one file, it only formats the first file.

For example:

$ caddy fmt 1.Caddyfile 2.Caddyfile --overwrite

then 1.Caddyfile will be reformatted, but 2.Caddyfile will be silently ignored.

If I look in the docs, I can see that caddy fmt only supports passing a single path – but it took me a while to realise that! This is different from other formatting tools I've used (e.g. black, terraform fmt) where you can pass multiple files and format them all together.

I think it would be less confusing if caddy fmt either:

• Formatted every <path> passed to it, or
• Threw an error if you tried to pass more than one <path>

Context

I'd written a command to find all the Caddyfiles in my repo and format them:

$ find . -name Caddyfile | xargs --verbose caddy fmt
caddy fmt 1/Caddyfile 2/Caddyfile

and I was getting inconsistent results between different machines – it took me a while to notice that find was returning results in an inconsistent order, and caddy was only formatting the first in the list.

I don't really mind what caddy does, but the current behaviour caused a lot of confusion.

Version

$ caddy --version
v2.8.4 h1:q3pe0wpBj1OcHFZ3n/1nl4V4bxBrYoSoab7rL9BMYNk=

[mholt]

Thanks for the report. Should be an easy fix, I suppose -- anyone is welcome to contribute!

[alexwlchan]

Noting in case I have time to pick this up: this looks like the relevant function.

caddy/cmd/commandfuncs.go

Lines 561 to 619 in eddbccd

	func cmdFmt(fl Flags) (int, error) {
	configFile := fl.Arg(0)
	if configFile == "" {
	configFile = "Caddyfile"
	}
	// as a special case, read from stdin if the file name is "-"
	if configFile == "-" {
	input, err := io.ReadAll(os.Stdin)
	if err != nil {
	return caddy.ExitCodeFailedStartup,
	fmt.Errorf("reading stdin: %v", err)
	}
	fmt.Print(string(caddyfile.Format(input)))
	return caddy.ExitCodeSuccess, nil
	}
	input, err := os.ReadFile(configFile)
	if err != nil {
	return caddy.ExitCodeFailedStartup,
	fmt.Errorf("reading input file: %v", err)
	}
	output := caddyfile.Format(input)
	if fl.Bool("overwrite") {
	if err := os.WriteFile(configFile, output, 0o600); err != nil {
	return caddy.ExitCodeFailedStartup, fmt.Errorf("overwriting formatted file: %v", err)
	}
	return caddy.ExitCodeSuccess, nil
	}
	if fl.Bool("diff") {
	diff := difflib.Diff(
	strings.Split(string(input), "\n"),
	strings.Split(string(output), "\n"))
	for _, d := range diff {
	switch d.Delta {
	case difflib.Common:
	fmt.Printf(" %s\n", d.Payload)
	case difflib.LeftOnly:
	fmt.Printf("- %s\n", d.Payload)
	case difflib.RightOnly:
	fmt.Printf("+ %s\n", d.Payload)
	}
	}
	} else {
	fmt.Print(string(output))
	}
	if warning, diff := caddyfile.FormattingDifference(configFile, input); diff {
	return caddy.ExitCodeFailedStartup, fmt.Errorf(`%s:%d: Caddyfile input is not formatted; Tip: use '--overwrite' to update your Caddyfile in-place instead of previewing it. Consult '--help' for more options`,
	warning.File,
	warning.Line,
	)
	}
	return caddy.ExitCodeSuccess, nil
	}

[francislavoie]

Well, you can only have one root Caddyfile, so I don't think it really makes sense to try to format more than one. If you're doing that because you have import etc, then I think we should update fmt to follow imports, possibly, and also format those files (when -w is used).

So I think yeah disallowing more than one file probably makes sense.

Also while we're at it I think we could add --config as a flag (which is the same as the one arg, and if set args can be empty), cause most of Caddy's other commands use --config/-c to specify the config file, ran into that on occasion as a footgun when I'm hitting UP in my terminal to edit the command and run another.

[alexwlchan]

If you're doing that because you have import etc, then I think we should update fmt to follow imports, possibly, and also format those files (when -w is used).

Yeah, imported files is precisely where I ran into this.