client/isolate: add skeleton exparchive command

client/cmd/isolate/exp_archive.go

Index: client/cmd/isolate/exp_archive.go
diff --git a/client/cmd/isolate/exp_archive.go b/client/cmd/isolate/exp_archive.go
new file mode 100644
index 0000000000000000000000000000000000000000..f7ee9b393c424f22216fefa39d6f4d44d37fdbaf
--- /dev/null
+++ b/client/cmd/isolate/exp_archive.go
@@ -0,0 +1,102 @@
+// Copyright 2015 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/luci/luci-go/client/isolate"
+	"github.com/luci/luci-go/common/isolated"
+	"github.com/maruel/subcommands"
+)
+
+var cmdExpArchive = &subcommands.Command{
+	UsageLine: "exparchive <options>",
+	ShortDesc: "EXPERIMENTAL parses a .isolate file to create a .isolated file, and uploads it and all referenced files to an isolate server",
+	LongDesc:  "All the files listed in the .isolated file are put in the isolate server cache. Small files are combined together in a tar archive before uploading.",
+	CommandRun: func() subcommands.CommandRun {
+		c := &expArchiveRun{}
+		c.commonServerFlags.Init()
+		c.isolateFlags.Init(&c.Flags)
+		c.archiveOpts = &c.isolateFlags.ArchiveOptions
+		return c
+	},
+}
+
+// expArchiveRun contains the logic for the experimental archive subcommand.
+// It implements subcommand.CommandRun
+type expArchiveRun struct {
+	commonServerFlags // Provides the GetFlags method.
+	isolateFlags      isolateFlags
+	archiveOpts       *isolate.ArchiveOptions

[mcgreevy, 2016/11/23 00:25:22]

As discussed, when reading this it takes extra effort to verify that archiveOpts
just points to a field within isolateFlags.  I think pulling it out at the top
of main is clearer.

+}
+
+// main contains the core logic for experimental archive.
+func (c *expArchiveRun) main() error {
+	// Parse the incoming isolate file.
+	deps, rootDir, isol, err := isolate.ProcessIsolate(c.archiveOpts)
+	if err != nil {
+		return fmt.Errorf("failed to process isolate: %v", err)
+	}
+	log.Printf("Isolate referenced %d deps", len(deps))
+
+	// TODO(djd): actually do something with the isolated.
+	_ = rootDir
+
+	// Marshal the isolated file into JSON.
+	isolJSON, err := json.Marshal(isol)
+	if err != nil {
+		return err
+	}
+	// TODO(djd): actually check/upload the isolated.
+
+	// Write the isolated file, and emit its digest to stdout.
+	if err := ioutil.WriteFile(c.archiveOpts.Isolated, isolJSON, 0644); err != nil {
+		return err
+	}
+	fmt.Printf("%s\t%s\n", isolated.HashBytes(isolJSON), filepath.Base(c.archiveOpts.Isolated))
+
+	return errors.New("experimental archive is not implemented")
+}
+
+func (c *expArchiveRun) parseFlags(args []string) error {
+	if len(args) != 0 {
+		return errors.New("position arguments not expected")
+	}
+	if err := c.commonServerFlags.Parse(); err != nil {
+		return err
+	}
+	cwd, err := os.Getwd()
+	if err != nil {
+		return err
+	}
+	if err := c.isolateFlags.Parse(cwd, RequireIsolateFile&RequireIsolatedFile); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *expArchiveRun) Run(a subcommands.Application, args []string) int {
+	fmt.Fprintln(a.GetErr(), "WARNING: this command is experimental")
+	if err := c.parseFlags(args); err != nil {
+		fmt.Fprintf(a.GetErr(), "%s: %s\n", a.GetName(), err)
+		return 1
+	}
+	if len(c.archiveOpts.Blacklist) != 0 {
+		fmt.Fprintf(a.GetErr(), "%s: blacklist is not supported\n", a.GetName())
+		return 1
+	}
+	if err := c.main(); err != nil {
+		fmt.Fprintf(a.GetErr(), "%s: %s\n", a.GetName(), err)
+		return 1
+	}
+	return 0
+}