client/isolate: add skeleton exparchive command

client/cmd/isolate/exp_archive.go

+// 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
+}