feat(cli): allow specifying name of provisioner daemon (#11077)

- Adds a --name argument to provisionerd start
- Plumbs through name to integrated and external provisioners
- Defaults to hostname if not specified for external, hostname-N for integrated
- Adds cliutil.Hostname

enterprise/wsproxy/wsproxy.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
-	"os"
 	"reflect"
 	"regexp"
 	"strings"
@@ -27,6 +26,7 @@ import (
 
 	"cdr.dev/slog"
 	"github.com/coder/coder/v2/buildinfo"
+	"github.com/coder/coder/v2/cli/cliutil"
 	"github.com/coder/coder/v2/coderd"
 	"github.com/coder/coder/v2/coderd/httpapi"
 	"github.com/coder/coder/v2/coderd/httpmw"
@@ -206,10 +206,7 @@ func New(ctx context.Context, opts *Options) (*Server, error) {
 	// Register the workspace proxy with the primary coderd instance and start a
 	// goroutine to periodically re-register.
 	replicaID := uuid.New()
-	osHostname, err := os.Hostname()
-	if err != nil {
-		return nil, xerrors.Errorf("get OS hostname: %w", err)
-	}
+	osHostname := cliutil.Hostname()
 	regResp, registerDone, err := client.RegisterWorkspaceProxyLoop(ctx, wsproxysdk.RegisterWorkspaceProxyLoopOpts{
 		Logger: opts.Logger,
 		Request: wsproxysdk.RegisterWorkspaceProxyRequest{