TUN-2640: Users can configure per-origin config. Unify single-rule CLI

flow with multi-rule config file code.

ingress/rule.go

@@ -0,0 +1,57 @@
+package ingress
+
+import (
+	"crypto/tls"
+	"net/http"
+	"regexp"
+	"strings"
+)
+
+// Rule routes traffic from a hostname/path on the public internet to the
+// service running on the given URL.
+type Rule struct {
+	// Requests for this hostname will be proxied to this rule's service.
+	Hostname string
+
+	// Path is an optional regex that can specify path-driven ingress rules.
+	Path *regexp.Regexp
+
+	// A (probably local) address. Requests for a hostname which matches this
+	// rule's hostname pattern will be proxied to the service running on this
+	// address.
+	Service OriginService
+
+	// Configure the request cloudflared sends to this specific origin.
+	Config OriginRequestConfig
+
+	// Configures TLS for the cloudflared -> origin request
+	ClientTLSConfig *tls.Config
+	// Configures HTTP for the cloudflared -> origin request
+	HTTPTransport http.RoundTripper
+}
+
+// MultiLineString is for outputting rules in a human-friendly way when Cloudflared
+// is used as a CLI tool (not as a daemon).
+func (r Rule) MultiLineString() string {
+	var out strings.Builder
+	if r.Hostname != "" {
+		out.WriteString("\thostname: ")
+		out.WriteString(r.Hostname)
+		out.WriteRune('\n')
+	}
+	if r.Path != nil {
+		out.WriteString("\tpath: ")
+		out.WriteString(r.Path.String())
+		out.WriteRune('\n')
+	}
+	out.WriteString("\tservice: ")
+	out.WriteString(r.Service.String())
+	return out.String()
+}
+
+// Matches checks if the rule matches a given hostname/path combination.
+func (r *Rule) Matches(hostname, path string) bool {
+	hostMatch := r.Hostname == "" || r.Hostname == "*" || matchHost(r.Hostname, hostname)
+	pathMatch := r.Path == nil || r.Path.MatchString(path)
+	return hostMatch && pathMatch
+}