httpcaddyfile: Validates TLS DNS challenge options

Adds validation to the TLS Caddyfile adapter to ensure that when DNS challenge options (such as propagation_delay or dns_ttl) are specified, a DNS provider is also configured.

Adds new integration tests to verify this validation logic, and implements a new mechanism for adapt tests to assert a config adapt error.

Author: francislavoie

caddyconfig/httpcaddyfile/builtins.go

@@ -130,6 +130,9 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 	var reusePrivateKeys bool
 	var forceAutomate bool
 
+	// Track which DNS challenge options are set
+	var dnsOptionsSet []string
+
 	firstLine := h.RemainingArgs()
 	switch len(firstLine) {
 	case 0:
@@ -350,6 +353,7 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 			if acmeIssuer.Challenges.DNS == nil {
 				acmeIssuer.Challenges.DNS = new(caddytls.DNSChallengeConfig)
 			}
+			dnsOptionsSet = append(dnsOptionsSet, "resolvers")
 			acmeIssuer.Challenges.DNS.Resolvers = args
 
 		case "propagation_delay":
@@ -371,6 +375,7 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 			if acmeIssuer.Challenges.DNS == nil {
 				acmeIssuer.Challenges.DNS = new(caddytls.DNSChallengeConfig)
 			}
+			dnsOptionsSet = append(dnsOptionsSet, "propagation_delay")
 			acmeIssuer.Challenges.DNS.PropagationDelay = caddy.Duration(delay)
 
 		case "propagation_timeout":
@@ -398,6 +403,7 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 			if acmeIssuer.Challenges.DNS == nil {
 				acmeIssuer.Challenges.DNS = new(caddytls.DNSChallengeConfig)
 			}
+			dnsOptionsSet = append(dnsOptionsSet, "propagation_timeout")
 			acmeIssuer.Challenges.DNS.PropagationTimeout = caddy.Duration(timeout)
 
 		case "dns_ttl":
@@ -419,6 +425,7 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 			if acmeIssuer.Challenges.DNS == nil {
 				acmeIssuer.Challenges.DNS = new(caddytls.DNSChallengeConfig)
 			}
+			dnsOptionsSet = append(dnsOptionsSet, "dns_ttl")
 			acmeIssuer.Challenges.DNS.TTL = caddy.Duration(ttl)
 
 		case "dns_challenge_override_domain":
@@ -435,6 +442,7 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 			if acmeIssuer.Challenges.DNS == nil {
 				acmeIssuer.Challenges.DNS = new(caddytls.DNSChallengeConfig)
 			}
+			dnsOptionsSet = append(dnsOptionsSet, "dns_challenge_override_domain")
 			acmeIssuer.Challenges.DNS.OverrideDomain = arg[0]
 
 		case "ca_root":
@@ -470,6 +478,18 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 		}
 	}
 
+	// Validate DNS challenge config: any DNS challenge option except "dns" requires a DNS provider
+	if acmeIssuer != nil && acmeIssuer.Challenges != nil && acmeIssuer.Challenges.DNS != nil {
+		dnsCfg := acmeIssuer.Challenges.DNS
+		providerSet := dnsCfg.ProviderRaw != nil || h.Option("dns") != nil
+		if len(dnsOptionsSet) > 0 && !providerSet {
+			return nil, h.Errf(
+				"setting DNS challenge options [%s] requires a DNS provider (set with the 'dns' subdirective or 'acme_dns' global option)",
+				strings.Join(dnsOptionsSet, ", "),
+			)
+		}
+	}
+
 	// a naked tls directive is not allowed
 	if len(firstLine) == 0 && !hasBlock {
 		return nil, h.ArgErr()

caddytest/integration/caddyfile_adapt/tls_dns_multiple_options_without_provider.caddyfiletest

@@ -0,0 +1,9 @@
+localhost
+
+tls {
+	propagation_delay 10s
+	dns_ttl 5m
+}
+
+----------
+parsing caddyfile tokens for 'tls': setting DNS challenge options [propagation_delay, dns_ttl] requires a DNS provider (set with the 'dns' subdirective or 'acme_dns' global option), at Caddyfile:6

caddytest/integration/caddyfile_adapt/tls_dns_propagation_timeout_without_provider.caddyfiletest

@@ -0,0 +1,7 @@
+:443 {
+	tls {
+		propagation_timeout 30s
+	}
+}
+----------
+parsing caddyfile tokens for 'tls': setting DNS challenge options [propagation_timeout] requires a DNS provider (set with the 'dns' subdirective or 'acme_dns' global option), at Caddyfile:4

caddytest/integration/caddyfile_adapt/tls_dns_propagation_without_provider.caddyfiletest

@@ -0,0 +1,7 @@
+:443 {
+	tls {
+		propagation_delay 30s
+	}
+}
+----------
+parsing caddyfile tokens for 'tls': setting DNS challenge options [propagation_delay] requires a DNS provider (set with the 'dns' subdirective or 'acme_dns' global option), at Caddyfile:4

caddytest/integration/caddyfile_adapt/tls_dns_ttl.caddyfiletest

@@ -2,6 +2,7 @@ localhost
 
 respond "hello from localhost"
 tls {
+	dns mock
 	dns_ttl 5m10s
 }
 ----------
@@ -54,6 +55,9 @@ tls {
 							{
 								"challenges": {
 									"dns": {
+										"provider": {
+											"name": "mock"
+										},
 										"ttl": 310000000000
 									}
 								},

caddytest/integration/caddyfile_adapt/tls_propagation_options.caddyfiletest

@@ -2,6 +2,7 @@ localhost
 
 respond "hello from localhost"
 tls {
+	dns mock
 	propagation_delay 5m10s
 	propagation_timeout 10m20s
 }
@@ -56,7 +57,10 @@ tls {
 								"challenges": {
 									"dns": {
 										"propagation_delay": 310000000000,
-										"propagation_timeout": 620000000000
+										"propagation_timeout": 620000000000,
+										"provider": {
+											"name": "mock"
+										}
 									}
 								},
 								"module": "acme"

caddytest/integration/caddyfile_adapt_test.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/caddyserver/caddy/v2/caddyconfig"
 	"github.com/caddyserver/caddy/v2/caddytest"
 	_ "github.com/caddyserver/caddy/v2/internal/testmocks"
 )
@@ -27,30 +28,48 @@ func TestCaddyfileAdaptToJSON(t *testing.T) {
 		if f.IsDir() {
 			continue
 		}
-
-		// read the test file
 		filename := f.Name()
-		data, err := os.ReadFile("./caddyfile_adapt/" + filename)
-		if err != nil {
-			t.Errorf("failed to read %s dir: %s", filename, err)
-		}
 
-		// split the Caddyfile (first) and JSON (second) parts
-		// (append newline to Caddyfile to match formatter expectations)
-		parts := strings.Split(string(data), "----------")
-		caddyfile, json := strings.TrimSpace(parts[0])+"\n", strings.TrimSpace(parts[1])
+		// run each file as a subtest, so that we can see which
+		// one fails and so that we can run them in parallel.
+		t.Run(filename, func(t *testing.T) {
+			t.Parallel()
 
-		// replace windows newlines in the json with unix newlines
-		json = winNewlines.ReplaceAllString(json, "\n")
+			// read the test file
+			data, err := os.ReadFile("./caddyfile_adapt/" + filename)
+			if err != nil {
+				t.Errorf("failed to read %s dir: %s", filename, err)
+			}
 
-		// replace os-specific default path for file_server's hide field
-		replacePath, _ := jsonMod.Marshal(fmt.Sprint(".", string(filepath.Separator), "Caddyfile"))
-		json = strings.ReplaceAll(json, `"./Caddyfile"`, string(replacePath))
+			// split the Caddyfile (first) and JSON (second) parts
+			// (append newline to Caddyfile to match formatter expectations)
+			parts := strings.Split(string(data), "----------")
+			caddyfile, expected := strings.TrimSpace(parts[0])+"\n", strings.TrimSpace(parts[1])
 
-		// run the test
-		ok := caddytest.CompareAdapt(t, filename, caddyfile, "caddyfile", json)
-		if !ok {
-			t.Errorf("failed to adapt %s", filename)
-		}
+			// replace windows newlines in the json with unix newlines
+			expected = winNewlines.ReplaceAllString(expected, "\n")
+
+			// replace os-specific default path for file_server's hide field
+			replacePath, _ := jsonMod.Marshal(fmt.Sprint(".", string(filepath.Separator), "Caddyfile"))
+			expected = strings.ReplaceAll(expected, `"./Caddyfile"`, string(replacePath))
+
+			// if the expected output is JSON, compare it
+			if len(expected) > 0 && expected[0] == '{' {
+				ok := caddytest.CompareAdapt(t, filename, caddyfile, "caddyfile", expected)
+				if !ok {
+					t.Errorf("failed to adapt %s", filename)
+				}
+				return
+			}
+
+			// otherwise, adapt the Caddyfile and check for errors
+			cfgAdapter := caddyconfig.GetAdapter("caddyfile")
+			_, _, err = cfgAdapter.Adapt([]byte(caddyfile), nil)
+			if err == nil {
+				t.Errorf("expected error for %s but got none", filename)
+			} else if !strings.Contains(err.Error(), expected) {
+				t.Errorf("expected error for %s to contain:\n%s\nbut got:\n%s", filename, expected, err.Error())
+			}
+		})
 	}
 }