Milo: Add machine pool info for buildbot builder view.

milo/api/resp/builder.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.
 
+//go:generate stringer -type=BotStatus

[nodir, 2017/06/13 02:38:40]

why is it so far from the BotStatus definition? consider moving this line closer

[Ryan Tseng, 2017/06/13 23:10:33]

This is to get go generate to create botstatus_string.go.  I think the
convention is to put it on top of the file before package and imports.

+
 package resp
 
 import "time"
 
 // Interval is a time interval which has a start, an end and a duration.
 type Interval struct {
         Started  time.Time     // when did this interval start
         Finished time.Time     // when did this interval finish
         Duration time.Duration // length of the interval; may be non-zero if Finished is zero
 }
@@ skipping 48 matching lines @@
         // machines that can run in a builder.  It has no meaning in buildbucket or dm
         // and is expected to be nil.
         MachinePool *MachinePool
 
         // PrevCursor is a cursor to the previous page.
         PrevCursor string `json:",omitempty"`
         // NextCursor is a cursor to the next page.
         NextCursor string `json:",omitempty"`
 }
 
+type BotStatus int
+
+const (
+        Unknown BotStatus = iota

[nodir, 2017/06/13 02:38:40]

This is a package-global constant. Consider renaming thisto UnknownStatus or
something. 

[Ryan Tseng, 2017/06/13 23:10:33]

Done.  Going to keep the below 3 as is since it makes for less code on the
rendering side.

+        Idle
+        Busy
+        Disconnected
+)
+
+// Bot represents a single bot.
+type Bot struct {
+        Name   *Link
+        Status BotStatus
+}
+
 // MachinePool represents the capacity and availability of a builder.
 type MachinePool struct {
-        Connected int
-        Total     int
-        Free      int
-        Used      int
+        Total        int
+        Disconnected int
+        Idle         int
+        Busy         int
+        Bots         []Bot
 }