From 2cac3c5491e6428441ecf668cc4f5a86e67ed9b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C4=90=E1=BB=97=20Tr=E1=BB=8Dng=20H=E1=BA=A3i?=
 <41283691+hainenber@users.noreply.github.com>
Date: Sat, 9 Sep 2023 01:38:44 +0700
Subject: httpcaddyfile: fix placeholder shorthands in named routes (#5791)

Co-authored-by: Francis Lavoie <lavofr@gmail.com>
---
 caddyconfig/httpcaddyfile/shorthands.go | 92 +++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 caddyconfig/httpcaddyfile/shorthands.go

(limited to 'caddyconfig/httpcaddyfile/shorthands.go')

diff --git a/caddyconfig/httpcaddyfile/shorthands.go b/caddyconfig/httpcaddyfile/shorthands.go
new file mode 100644
index 0000000..102bc36
--- /dev/null
+++ b/caddyconfig/httpcaddyfile/shorthands.go
@@ -0,0 +1,92 @@
+package httpcaddyfile
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+)
+
+type ComplexShorthandReplacer struct {
+	search  *regexp.Regexp
+	replace string
+}
+
+type ShorthandReplacer struct {
+	complex []ComplexShorthandReplacer
+	simple  *strings.Replacer
+}
+
+func NewShorthandReplacer() ShorthandReplacer {
+	// replace shorthand placeholders (which are convenient
+	// when writing a Caddyfile) with their actual placeholder
+	// identifiers or variable names
+	replacer := strings.NewReplacer(placeholderShorthands()...)
+
+	// these are placeholders that allow a user-defined final
+	// parameters, but we still want to provide a shorthand
+	// for those, so we use a regexp to replace
+	regexpReplacements := []ComplexShorthandReplacer{
+		{regexp.MustCompile(`{header\.([\w-]*)}`), "{http.request.header.$1}"},
+		{regexp.MustCompile(`{cookie\.([\w-]*)}`), "{http.request.cookie.$1}"},
+		{regexp.MustCompile(`{labels\.([\w-]*)}`), "{http.request.host.labels.$1}"},
+		{regexp.MustCompile(`{path\.([\w-]*)}`), "{http.request.uri.path.$1}"},
+		{regexp.MustCompile(`{file\.([\w-]*)}`), "{http.request.uri.path.file.$1}"},
+		{regexp.MustCompile(`{query\.([\w-]*)}`), "{http.request.uri.query.$1}"},
+		{regexp.MustCompile(`{re\.([\w-]*)\.([\w-]*)}`), "{http.regexp.$1.$2}"},
+		{regexp.MustCompile(`{vars\.([\w-]*)}`), "{http.vars.$1}"},
+		{regexp.MustCompile(`{rp\.([\w-\.]*)}`), "{http.reverse_proxy.$1}"},
+		{regexp.MustCompile(`{err\.([\w-\.]*)}`), "{http.error.$1}"},
+		{regexp.MustCompile(`{file_match\.([\w-]*)}`), "{http.matchers.file.$1}"},
+	}
+
+	return ShorthandReplacer{
+		complex: regexpReplacements,
+		simple:  replacer,
+	}
+}
+
+// placeholderShorthands returns a slice of old-new string pairs,
+// where the left of the pair is a placeholder shorthand that may
+// be used in the Caddyfile, and the right is the replacement.
+func placeholderShorthands() []string {
+	return []string{
+		"{dir}", "{http.request.uri.path.dir}",
+		"{file}", "{http.request.uri.path.file}",
+		"{host}", "{http.request.host}",
+		"{hostport}", "{http.request.hostport}",
+		"{port}", "{http.request.port}",
+		"{method}", "{http.request.method}",
+		"{path}", "{http.request.uri.path}",
+		"{query}", "{http.request.uri.query}",
+		"{remote}", "{http.request.remote}",
+		"{remote_host}", "{http.request.remote.host}",
+		"{remote_port}", "{http.request.remote.port}",
+		"{scheme}", "{http.request.scheme}",
+		"{uri}", "{http.request.uri}",
+		"{tls_cipher}", "{http.request.tls.cipher_suite}",
+		"{tls_version}", "{http.request.tls.version}",
+		"{tls_client_fingerprint}", "{http.request.tls.client.fingerprint}",
+		"{tls_client_issuer}", "{http.request.tls.client.issuer}",
+		"{tls_client_serial}", "{http.request.tls.client.serial}",
+		"{tls_client_subject}", "{http.request.tls.client.subject}",
+		"{tls_client_certificate_pem}", "{http.request.tls.client.certificate_pem}",
+		"{tls_client_certificate_der_base64}", "{http.request.tls.client.certificate_der_base64}",
+		"{upstream_hostport}", "{http.reverse_proxy.upstream.hostport}",
+		"{client_ip}", "{http.vars.client_ip}",
+	}
+}
+
+// ApplyToSegment replaces shorthand placeholder to its full placeholder, understandable by Caddy.
+func (s ShorthandReplacer) ApplyToSegment(segment *caddyfile.Segment) {
+	if segment != nil {
+		for i := 0; i < len(*segment); i++ {
+			// simple string replacements
+			(*segment)[i].Text = s.simple.Replace((*segment)[i].Text)
+			// complex regexp replacements
+			for _, r := range s.complex {
+				(*segment)[i].Text = r.search.ReplaceAllString((*segment)[i].Text, r.replace)
+			}
+		}
+	}
+}
-- 
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