(2.8.0-beta.1) CEL expressions in Caddyfile not processed properly

[inetol]

Expressions written in heredoc such as:

@cel_tld_net <<CEL
    {http.request.host.labels.0} == "net"
    CEL

...or with backticks:

@cel_tld_net `{http.request.host.labels.0} == "net"`

...are not processed correctly in Caddyfiles as of 2.8.0-beta.1, leading to this error:

Error: adapting config using caddyfile: wrong argument count or unexpected line ending after 'expression', at /path/to/config

But it does work correctly if you explicitly specify the expression parameter, like so:

@cel_tld_net expression {http.request.host.labels.0} == "net"

Anyway, thanks for your amazing work!

[francislavoie]

Works fine for me.

:8881 {
    @test `{http.request.host.labels.0} == "net"`
    respond @test "hello"
}

👇 caddy adapt -p

{
	"apps": {
		"http": {
			"servers": {
				"srv0": {
					"listen": [
						":8881"
					],
					"routes": [
						{
							"match": [
								{
									"expression": {
										"expr": "{http.request.host.labels.0} == \"net\"",
										"name": "test"
									}
								}
							],
							"handle": [
								{
									"body": "hello",
									"handler": "static_response"
								}
							]
						}
					]
				}
			}
		}
	}
}

[francislavoie]

Please share your full Caddyfile, the problem must be caused by something else (or in combination with something else).

[inetol]

It seems that the error only manifests itself if used in conjunction with import 😓, here is a minimal example to reproduce the issue:

# Caddyfile
:8080 {
	import expression.cel

	handle @cel_tld_net {
		respond ":)"
	}

	handle {
		respond ":("
	}
}

# expression.cel
@cel_tld_net <<CEL
	{http.request.host.labels.0} == "net"
	CEL

[francislavoie]

Okay, thanks, I can replicate that. Looking into it.

[francislavoie]

Got a fix! #6288

The crux of the issue is with how we make a fake expression token which we insert just before the backtick-quoted CEL expression. This worked fine in the base case with no import. But when there's imports, the tokens carry their inheritance path through snippets/files. The fake expression token wasn't using the CEL expression token's inheritance, so the token dispenser got confused because they didn't make sense consecutively. Now I'm literally cloning the token (preserving all the context) and just replacing its text with expression and using that. It works.