LogDog: Update client/bootstrap to generate URLs.

logdog/client/butlerlib/bootstrap/bootstrap.go

Index: logdog/client/butlerlib/bootstrap/bootstrap.go
diff --git a/logdog/client/butlerlib/bootstrap/bootstrap.go b/logdog/client/butlerlib/bootstrap/bootstrap.go
index 34ee46e1942f4ecee15422112a14ffb087b95c8d..c9e9bc8370027a2018f15ffc7b35c65a8dde647a 100644
--- a/logdog/client/butlerlib/bootstrap/bootstrap.go
+++ b/logdog/client/butlerlib/bootstrap/bootstrap.go
@@ -5,13 +5,14 @@
 package bootstrap
 
 import (
-	"errors"
 	"fmt"
 
 	"github.com/luci/luci-go/client/environ"
 	"github.com/luci/luci-go/common/config"
+	"github.com/luci/luci-go/common/errors"
 	"github.com/luci/luci-go/logdog/client/butlerlib/streamclient"
 	"github.com/luci/luci-go/logdog/common/types"
+	"github.com/luci/luci-go/logdog/common/viewer"
 )
 
 // ErrNotBootstrapped is returned by Get when the current process is not
@@ -62,19 +63,58 @@ func getFromEnv(env environ.Environment, reg *streamclient.Registry) (*Bootstrap
 
 	// If we have a stream server attached; instantiate a stream Client.
 	if p, ok := env[EnvStreamServerPath]; ok {
-		c, err := reg.NewClient(p)
-		if err != nil {
+		if err := bs.initializeClient(p, reg); err != nil {
 			return nil, fmt.Errorf("bootstrap: failed to create stream client [%s]: %s", p, err)
 		}
-		bs.Client = c
 	}
 
 	return bs, nil
 }
 
+func (bs *Bootstrap) initializeClient(v string, reg *streamclient.Registry) error {
+	c, err := reg.NewClient(v)
+	if err != nil {
+		return errors.Annotate(err).Reason("bootstrap: failed to create stream client [%(config)s]").D("config", v).Err()
+	}
+	bs.Client = c
+	return nil
+}
+
 // Get loads a Bootstrap instance from the environment. It will return an error
 // if the bootstrap data is invalid, and will return ErrNotBootstrapped if the
 // current process is not bootstrapped.
 func Get() (*Bootstrap, error) {
-	return getFromEnv(environ.Get(), streamclient.DefaultRegistry)
+	return getFromEnv(environ.Get(), streamclient.GetDefaultRegistry())
+}
+
+// GetViewerURL returns a log stream viewer URL to the aggregate set of supplied
+// stream paths.
+//
+// If both the Project and CoordinatorHost values are not populated, an error
+// will be returned.
+func (bs *Bootstrap) GetViewerURL(paths ...types.StreamPath) (string, error) {
+	if bs.Project == "" {
+		return "", errors.New("no project is configured")
+	}
+	if bs.CoordinatorHost == "" {
+		return "", errors.New("no coordinator host is configured")
+	}
+	return viewer.GetURL(bs.CoordinatorHost, bs.Project, paths...), nil
+}
+
+// GetViewerURLForStreams returns a log stream viewer URL to the aggregate set
+// of supplied streams.
+//
+// If the any of the Prefix, Project, or CoordinatorHost values is not
+// populated, an error will be returned.
+func (bs *Bootstrap) GetViewerURLForStreams(streams ...streamclient.Stream) (string, error) {
+	if bs.Prefix == "" {
+		return "", errors.New("no prefix is configured")
+	}
+
+	paths := make([]types.StreamPath, len(streams))
+	for i, s := range streams {
+		paths[i] = bs.Prefix.Join(types.StreamName(s.Properties().Name))
+	}
+	return bs.GetViewerURL(paths...)
 }