AUTH-2588 add DoH to service mode

cmd/cloudflared/config/model.go

@@ -4,6 +4,7 @@ import (
 	"crypto/md5"
 	"fmt"
 	"io"
+	"strings"
 )
 
 // Forwarder represents a client side listener to forward traffic to the edge
@@ -19,6 +20,15 @@ type Tunnel struct {
 	ProtocolType string `json:"type"`
 }
 
+// DNSResolver represents a client side DNS resolver
+type DNSResolver struct {
+	Enabled    bool     `json:"enabled"`
+	Address    string   `json:"address"`
+	Port       uint16   `json:"port"`
+	Upstreams  []string `json:"upstreams"`
+	Bootstraps []string `json:"bootstraps"`
+}
+
 // Root is the base options to configure the service
 type Root struct {
 	OrgKey          string      `json:"org_key"`
@@ -26,6 +36,7 @@ type Root struct {
 	CheckinInterval int         `json:"checkin_interval"`
 	Forwarders      []Forwarder `json:"forwarders,omitempty"`
 	Tunnels         []Tunnel    `json:"tunnels,omitempty"`
+	Resolver        DNSResolver `json:"resolver"`
 }
 
 // Hash returns the computed values to see if the forwarder values change
@@ -35,3 +46,51 @@ func (f *Forwarder) Hash() string {
 	io.WriteString(h, f.Listener)
 	return fmt.Sprintf("%x", h.Sum(nil))
 }
+
+// Hash returns the computed values to see if the forwarder values change
+func (r *DNSResolver) Hash() string {
+	h := md5.New()
+	io.WriteString(h, r.Address)
+	io.WriteString(h, strings.Join(r.Bootstraps, ","))
+	io.WriteString(h, strings.Join(r.Upstreams, ","))
+	io.WriteString(h, fmt.Sprintf("%d", r.Port))
+	io.WriteString(h, fmt.Sprintf("%v", r.Enabled))
+	return fmt.Sprintf("%x", h.Sum(nil))
+}
+
+// EnabledOrDefault returns the enabled property
+func (r *DNSResolver) EnabledOrDefault() bool {
+	return r.Enabled
+}
+
+// AddressOrDefault returns the address or returns the default if empty
+func (r *DNSResolver) AddressOrDefault() string {
+	if r.Address != "" {
+		return r.Address
+	}
+	return "localhost"
+}
+
+// PortOrDefault return the port or returns the default if 0
+func (r *DNSResolver) PortOrDefault() uint16 {
+	if r.Port > 0 {
+		return r.Port
+	}
+	return 53
+}
+
+// UpstreamsOrDefault returns the upstreams or returns the default if empty
+func (r *DNSResolver) UpstreamsOrDefault() []string {
+	if len(r.Upstreams) > 0 {
+		return r.Upstreams
+	}
+	return []string{"https://1.1.1.1/dns-query", "https://1.0.0.1/dns-query"}
+}
+
+// BootstrapsOrDefault returns the bootstraps or returns the default if empty
+func (r *DNSResolver) BootstrapsOrDefault() []string {
+	if len(r.Bootstraps) > 0 {
+		return r.Bootstraps
+	}
+	return []string{"https://162.159.36.1/dns-query", "https://162.159.46.1/dns-query", "https://[2606:4700:4700::1111]/dns-query", "https://[2606:4700:4700::1001]/dns-query"}
+}