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 creates a .isolated file and uploads the tree to an isolate server.",

[mcgreevy, 2016/11/22 05:12:12]

"the tree" can you be more explicit? what tree?

[djd-OOO-Apr2017, 2016/11/22 06:12:20]

Tried to add a lot more explanatory text, PTAL.

+        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)
+                return &c
+        },
+}
+
+type expArchiveRun struct {

[mcgreevy, 2016/11/22 05:12:12]

Can you please document this?

[djd-OOO-Apr2017, 2016/11/22 06:12:20]

Done.

+        commonServerFlags

[mcgreevy, 2016/11/22 05:12:12]

Is there any reason for these to be anonymous fields? I generally try to avoid
them unless I want methods on the anonymous fields to be promoted.

[djd-OOO-Apr2017, 2016/11/22 06:12:20]

commonServerFlags needed to satisfy the subcommand.CommandRun interface.

I've named the isolateFlags field now (the only reason I could see to make it
anon. was to shorten the references to ArchiveOptions below).

+        isolateFlags
+}
+
+func (c *expArchiveRun) Parse(a subcommands.Application, args []string) error {
+        if err := c.commonServerFlags.Parse(); err != nil {
+                return err
+        }
+        cwd, err := os.Getwd()
+        if err != nil {
+                return err
+        }
+        if err := c.isolateFlags.Parse(cwd, RequireIsolatedFile); err != nil {

[mcgreevy, 2016/11/22 05:12:12]

Don't you need "RequireIsolateFile&RequireIsolatedFile" here?  I think that line
57 assumes that c.ArchiveOptions contains an isolate file.

[djd-OOO-Apr2017, 2016/11/22 06:12:20]

Good call, fixed.

+                return err
+        }
+        if len(args) != 0 {
+                return errors.New("position arguments not expected")
+        }
+        return nil
+}
+
+func (c *expArchiveRun) main(a subcommands.Application, args []string) error {
+        // Parse the incoming isolate file.
+        deps, rootDir, isol, err := isolate.ProcessIsolate(&c.ArchiveOptions)
+        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.ArchiveOptions.Isolated, isolJSON, 0644); err != nil {
+                return err
+        }
+        fmt.Printf("%s\t%s\n", isolated.HashBytes(isolJSON), filepath.Base(c.ArchiveOptions.Isolated))
+
+        return errors.New("experimental archive is not implemented")
+}
+
+func (c *expArchiveRun) Run(a subcommands.Application, args []string) int {
+        fmt.Fprintln(a.GetErr(), "WARNING: this command is experimental")
+        if err := c.Parse(a, args); err != nil {
+                fmt.Fprintf(a.GetErr(), "%s: %s\n", a.GetName(), err)
+                return 1
+        }
+        if len(c.ArchiveOptions.Blacklist) != 0 {
+                fmt.Fprintf(a.GetErr(), "%s: blacklist is not supported\n", a.GetName())
+                return 1
+        }
+        if err := c.main(a, args); err != nil {
+                fmt.Fprintf(a.GetErr(), "%s: %s\n", a.GetName(), err)
+                return 1
+        }
+        return 0
+}