feat(coderd): add provisioner build version and api_version on serve (#11369)

* assert provisioner daemon version and api_version in unit tests
* add build info in HTTP header, extract codersdk.BuildVersionHeader
* add api_version to codersdk.ProvisionerDaemon
* testutil.MustString -> testutil.MustRandString

codersdk/client.go

@@ -78,6 +78,9 @@ const (
 
 	// ProvisionerDaemonPSK contains the authentication pre-shared key for an external provisioner daemon
 	ProvisionerDaemonPSK = "Coder-Provisioner-Daemon-PSK"
+
+	// BuildVersionHeader contains build information of Coder.
+	BuildVersionHeader = "X-Coder-Build-Version"
 )
 
 // loggableMimeTypes is a list of MIME types that are safe to log

codersdk/provisionerdaemons.go

@@ -15,6 +15,7 @@ import (
 	"golang.org/x/xerrors"
 	"nhooyr.io/websocket"
 
+	"github.com/coder/coder/v2/buildinfo"
 	"github.com/coder/coder/v2/codersdk/drpc"
 	"github.com/coder/coder/v2/provisionerd/proto"
 	"github.com/coder/coder/v2/provisionerd/runner"
@@ -41,6 +42,7 @@ type ProvisionerDaemon struct {
 	LastSeenAt   NullTime          `json:"last_seen_at,omitempty" format:"date-time"`
 	Name         string            `json:"name"`
 	Version      string            `json:"version"`
+	APIVersion   string            `json:"api_version"`
 	Provisioners []ProvisionerType `json:"provisioners"`
 	Tags         map[string]string `json:"tags"`
 }
@@ -212,6 +214,7 @@ func (c *Client) ServeProvisionerDaemon(ctx context.Context, req ServeProvisione
 	}
 	headers := http.Header{}
 
+	headers.Set(BuildVersionHeader, buildinfo.Version())
 	if req.PreSharedKey == "" {
 		// use session token if we don't have a PSK.
 		jar, err := cookiejar.New(nil)

codersdk/users.go

@@ -203,7 +203,7 @@ func (c *Client) HasFirstUser(ctx context.Context) (bool, error) {
 	if res.StatusCode == http.StatusNotFound {
 		// ensure we are talking to coder and not
 		// some other service that returns 404
-		v := res.Header.Get("X-Coder-Build-Version")
+		v := res.Header.Get(BuildVersionHeader)
 		if v == "" {
 			return false, xerrors.Errorf("missing build version header, not a coder instance")
 		}