LogDog: Update to archival V2.

appengine/logdog/coordinator/config/bigTable.go

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package config
-
-import (
-        gaeauthClient "github.com/luci/luci-go/appengine/gaeauth/client"
-        "github.com/luci/luci-go/common/errors"
-        log "github.com/luci/luci-go/common/logging"
-        "github.com/luci/luci-go/server/logdog/storage"
-        "github.com/luci/luci-go/server/logdog/storage/bigtable"
-        "golang.org/x/net/context"
-        "google.golang.org/cloud"
-        "google.golang.org/grpc/metadata"
-)
-
-// GetStorage returns a configured BigTable Storage instance.
-//
-// The instance is configured from the configuration returned by Get. Upon
-// success, the returned instance will need to be Close()'d when the caller has
-// finished with it.
-func GetStorage(c context.Context) (storage.Storage, error) {
-        gcfg, err := LoadGlobalConfig(c)
-        if err != nil {
-                log.WithError(err).Errorf(c, "Failed to load global configuration.")
-                return nil, err
-        }
-
-        cfg, err := gcfg.LoadConfig(c)
-        if err != nil {
-                log.WithError(err).Errorf(c, "Failed to load instance configuration.")
-                return nil, err
-        }
-
-        // Is BigTable configured?
-        if cfg.Storage == nil {
-                return nil, errors.New("no storage configuration")
-        }
-
-        bt := cfg.Storage.GetBigtable()
-        if bt == nil {
-                return nil, errors.New("no BigTable configuration")
-        }
-
-        // Validate the BigTable configuration.
-        log.Fields{
-                "project":      bt.Project,
-                "zone":         bt.Zone,
-                "cluster":      bt.Cluster,
-                "logTableName": bt.LogTableName,
-        }.Debugf(c, "Connecting to BigTable.")
-        var merr errors.MultiError
-        if bt.Project == "" {
-                merr = append(merr, errors.New("missing project"))
-        }
-        if bt.Zone == "" {
-                merr = append(merr, errors.New("missing zone"))
-        }
-        if bt.Cluster == "" {
-                merr = append(merr, errors.New("missing cluster"))
-        }
-        if bt.LogTableName == "" {
-                merr = append(merr, errors.New("missing log table name"))
-        }
-        if len(merr) > 0 {
-                return nil, merr
-        }
-
-        // Get an Authenticator bound to the token scopes that we need for BigTable.
-        a, err := gaeauthClient.Authenticator(c, bigtable.StorageScopes, gcfg.BigTableServiceAccountJSON)
-        if err != nil {
-                log.WithError(err).Errorf(c, "Failed to create BigTable authenticator.")
-                return nil, errors.New("failed to create BigTable authenticator")
-        }
-
-        // Explicitly clear gRPC metadata from the Context. It is forwarded to
-        // delegate calls by default, and standard request metadata can break BigTable
-        // calls.
-        c = metadata.NewContext(c, nil)
-
-        st, err := bigtable.New(c, bigtable.Options{
-                Project:  bt.Project,
-                Zone:     bt.Zone,
-                Cluster:  bt.Cluster,
-                LogTable: bt.LogTableName,
-                ClientOptions: []cloud.ClientOption{
-                        cloud.WithTokenSource(a.TokenSource()),
-                },
-        })
-        if err != nil {
-                log.WithError(err).Errorf(c, "Failed to create BigTable instance.")
-                return nil, err
-        }
-        return st, nil
-}