nsd: add support for setting headers on nomad service http checks

This PR enables setting of the headers block on services registered
into Nomad's service provider. Works just like the existing support
in Consul checks.

client/serviceregistration/checks/client.go

@@ -162,6 +162,7 @@ func (c *checker) checkHTTP(ctx context.Context, qc *QueryContext, q *Query) *st
 		qr.Status = structs.CheckFailure
 		return qr
 	}
+	request.Header = q.Headers
 	request = request.WithContext(ctx)
 
 	result, err := c.httpClient.Do(request)

client/serviceregistration/checks/client_test.go

@@ -261,6 +261,14 @@ func TestChecker_Do_HTTP_extras(t *testing.T) {
 			method:  "HEAD",
 			headers: makeHeaders(agent),
 		},
+		{
+			name:   "extra headers",
+			method: "GET",
+			headers: makeHeaders(encoding, agent,
+				[2]string{"X-My-Header", "hello"},
+				[2]string{"Authorization", "Basic ZWxhc3RpYzpjaGFuZ2VtZQ=="},
+			),
+		},
 	}
 
 	for _, tc := range cases {
@@ -286,19 +294,22 @@ func TestChecker_Do_HTTP_extras(t *testing.T) {
 			Protocol:    "http",
 			Path:        "/",
 			Method:      tc.method,
+			Headers:     tc.headers,
 		}
 
-		logger := testlog.HCLogger(t)
-		c := New(logger)
-		ctx := context.Background()
-		result := c.Do(ctx, qc, q)
-		must.Eq(t, http.StatusOK, result.StatusCode,
-			must.Sprintf("test.URL: %s", ts.URL),
-			must.Sprintf("headers: %v", tc.headers),
-		)
-		must.Eq(t, tc.method, method)
-		must.Eq(t, tc.body, string(body))
-		must.Eq(t, tc.headers, headers)
+		t.Run(tc.name, func(t *testing.T) {
+			logger := testlog.HCLogger(t)
+			c := New(logger)
+			ctx := context.Background()
+			result := c.Do(ctx, qc, q)
+			must.Eq(t, http.StatusOK, result.StatusCode,
+				must.Sprintf("test.URL: %s", ts.URL),
+				must.Sprintf("headers: %v", tc.headers),
+			)
+			must.Eq(t, tc.method, method)
+			must.Eq(t, tc.body, string(body))
+			must.Eq(t, tc.headers, headers)
+		})
 	}
 }
 

client/serviceregistration/checks/result.go

@@ -1,8 +1,10 @@
 package checks
 
 import (
+	"net/http"
 	"time"
 
+	"github.com/hashicorp/nomad/helper"
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
@@ -18,9 +20,10 @@ func GetCheckQuery(c *structs.ServiceCheck) *Query {
 		Timeout:     c.Timeout,
 		AddressMode: c.AddressMode,
 		PortLabel:   c.PortLabel,
+		Protocol:    protocol,
 		Path:        c.Path,
 		Method:      c.Method,
-		Protocol:    protocol,
+		Headers:     helper.CopyMap(c.Header),
 	}
 }
 
@@ -35,9 +38,10 @@ type Query struct {
 	AddressMode string // host, driver, or alloc
 	PortLabel   string // label or value
 
-	Protocol string // http checks only (http or https)
-	Path     string // http checks only
-	Method   string // http checks only
+	Protocol string      // http checks only (http or https)
+	Path     string      // http checks only
+	Method   string      // http checks only
+	Headers  http.Header // http checks only
 }
 
 // A QueryContext contains allocation and service parameters necessary for

nomad/structs/services.go

@@ -351,11 +351,6 @@ func (sc *ServiceCheck) validateNomad() error {
 			return fmt.Errorf("method type %q not supported in Nomad http check", sc.Method)
 		}
 
-		// todo(shoenig) support headers
-		if len(sc.Header) > 0 {
-			return fmt.Errorf("http checks may not set headers in Nomad services")
-		}
-
 		// todo(shoenig) support body
 		if len(sc.Body) > 0 {
 			return fmt.Errorf("http checks may not set Body in Nomad services")

nomad/structs/services_test.go

@@ -323,9 +323,11 @@ func TestServiceCheck_validateNomad(t *testing.T) {
 				Timeout:  1 * time.Second,
 				Path:     "/health",
 				Method:   "GET",
-				Header:   map[string][]string{"foo": {"bar"}},
+				Header: map[string][]string{
+					"foo": {"bar"},
+					"baz": nil,
+				},
 			},
-			exp: `http checks may not set headers in Nomad services`,
 		},
 		{
 			name: "http with body",