[milo] Refactor all html knowledge out of backends.

milo/buildsource/swarming/build.go

 // Copyright 2015 The LUCI Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 24 matching lines @@
         "github.com/luci/luci-go/logdog/common/types"
         "github.com/luci/luci-go/milo/api/resp"
         "github.com/luci/luci-go/milo/buildsource/rawpresentation"
         "github.com/luci/luci-go/milo/common"
         "github.com/luci/luci-go/milo/common/model"
         "github.com/luci/luci-go/server/auth"
 )
 
 // errNotMiloJob is returned if a Swarming task is fetched that does not self-
 // identify as a Milo job.
-var errNotMiloJob = errors.New("Not a Milo Job or access denied")
+var errNotMiloJob = errors.New("Not a Milo Job or access denied", common.CodeNoAccess)
 
 // SwarmingTimeLayout is time layout used by swarming.
 const SwarmingTimeLayout = "2006-01-02T15:04:05.999999999"
 
 // logDogFetchTimeout is the amount of time to wait while fetching a LogDog
 // stream before we time out the fetch.
 const logDogFetchTimeout = 30 * time.Second
 
 // Swarming task states..
 const (
@@ skipping 715 matching lines @@
         for _, tag := range v {
                 var value string
                 parts := strings.SplitN(tag, ":", 2)
                 if len(parts) == 2 {
                         value = parts[1]
                 }
                 res[parts[0]] = value
         }
         return res
 }
+
+// BuildID is swarming's notion of a Build. See buildsource.ID.
+type BuildID struct {
+        // (Required) The Swarming TaskID.
+        TaskID string
+
+        // (Optional) The Swarming host. If empty, will use the
+        // milo-instance-configured swarming host.
+        Host string
+}
+
+// getSwarmingHost parses the swarming hostname out of the context.  If
+// none is specified, get the default swarming host out of the global
+// configs.
+func (b *BuildID) getSwarmingHost(c context.Context) (server string, err error) {
+        server = b.Host
+        settings := common.GetSettings(c)
+        if settings.Swarming == nil {
+                err := errors.New("swarming not in settings")
+                logging.WithError(err).Errorf(c, "Go configure swarming in the settings page.")
+                return "", err
+        }
+        if server == "" || server == settings.Swarming.DefaultHost {
+                return settings.Swarming.DefaultHost, nil
+        }
+        // If it is specified, validate the hostname.
+        for _, hostname := range settings.Swarming.AllowedHosts {
+                if server == hostname {
+                        return server, nil
+                }
+        }
+        return "", errors.New("unknown swarming host", common.CodeParameterError)
+}
+
+func (b *BuildID) validate() error {
+        if b.TaskID == "" {
+                return errors.New("no swarming task id", common.CodeParameterError)
+        }
+        return nil
+}
+
+// Get implements buildsource.ID
+func (b *BuildID) Get(ctx context.Context) (*resp.MiloBuild, error) {

[Ryan Tseng, 2017/07/13 22:00:46]

nit: conventionally Milo uses "ctx" for router.Context and "c" for
context.Context.

[iannucci, 2017/07/14 19:00:22]

this is all goofy everywhere for reasons, but I'll try to match milo style here
:)

+        if err := b.validate(); err != nil {
+                return nil, err
+        }
+
+        hostname, err := b.getSwarmingHost(ctx)
+        if err != nil {
+                return nil, err
+        }
+        sf, err := NewProdService(ctx, hostname)
+        if err != nil {
+                return nil, err
+        }
+
+        return (&BuildLoader{}).SwarmingBuildImpl(ctx, sf, b.TaskID)
+}
+
+// GetLog implements buildsource.ID
+func (b *BuildID) GetLog(ctx context.Context, logname string) (text string, closed bool, err error) {
+        if err = b.validate(); err != nil {
+                return
+        }
+        if logname == "" {
+                err = errors.New("no log name", common.CodeParameterError)
+                return
+        }
+
+        hostname, err := b.getSwarmingHost(ctx)
+        if err != nil {
+                return
+        }
+
+        sf, err := NewProdService(ctx, hostname)
+        if err != nil {
+                return
+        }
+
+        return swarmingBuildLogImpl(ctx, sf, b.TaskID, logname)
+}