go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/logdog/common/storage/bigtable/flags.go (about)

     1  // Copyright 2021 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package bigtable
    16  
    17  import (
    18  	"context"
    19  	"flag"
    20  
    21  	"cloud.google.com/go/bigtable"
    22  	"google.golang.org/api/option"
    23  
    24  	"go.chromium.org/luci/common/errors"
    25  	"go.chromium.org/luci/server/auth"
    26  )
    27  
    28  // Flags contains the BigTable storage config.
    29  type Flags struct {
    30  	// Project is the name of the Cloud Project containing the BigTable instance.
    31  	Project string
    32  	// Instance if the name of the BigTable instance within the project.
    33  	Instance string
    34  	// LogTable is the name of the BigTable instance's log table.
    35  	LogTable string
    36  
    37  	// AppProfile is the BigTable application profile name to use (or "" for
    38  	// default).
    39  	//
    40  	// This is INTENTIONALLY not wired to a CLI flag; The value here is tied to
    41  	// the _code_, not the runtime environment of the code.
    42  	//
    43  	// The application profile must be configured in the GCP BigTable settings
    44  	// before use.
    45  	//
    46  	// However, in the future it may become necessary to disambiguate between e.g.
    47  	// prod and dev. If this is the case, then I would recommend StorageFromFlags
    48  	// adding "-prod" and "-dev" to the given AppProfile name here, rather than
    49  	// making it fully configurable as a CLI flag (to reduce coupling during
    50  	// rollouts).
    51  	AppProfile string
    52  }
    53  
    54  // Register registers flags in the flag set.
    55  func (f *Flags) Register(fs *flag.FlagSet) {
    56  	fs.StringVar(&f.Project, "bigtable-project", f.Project,
    57  		"Cloud Project containing the BigTable instance.")
    58  	fs.StringVar(&f.Instance, "bigtable-instance", f.Instance,
    59  		"BigTable instance within the project to use.")
    60  	fs.StringVar(&f.LogTable, "bigtable-log-table", f.LogTable,
    61  		"Name of the table with logs.")
    62  }
    63  
    64  // Validate returns an error if some parsed flags have invalid values.
    65  func (f *Flags) Validate() error {
    66  	if f.Project == "" {
    67  		return errors.New("-bigtable-project is required")
    68  	}
    69  	if f.Instance == "" {
    70  		return errors.New("-bigtable-instance is required")
    71  	}
    72  	if f.LogTable == "" {
    73  		return errors.New("-bigtable-log-table is required")
    74  	}
    75  	return nil
    76  }
    77  
    78  // StorageFromFlags instantiates the *bigtable.Storage given parsed flags.
    79  func StorageFromFlags(ctx context.Context, f *Flags) (*Storage, error) {
    80  	ts, err := auth.GetTokenSource(ctx, auth.AsSelf, auth.WithScopes(auth.CloudOAuthScopes...))
    81  	if err != nil {
    82  		return nil, errors.Annotate(err, "failed to get the token source").Err()
    83  	}
    84  	cCfg := bigtable.ClientConfig{
    85  		AppProfile: f.AppProfile,
    86  	}
    87  	client, err := bigtable.NewClientWithConfig(ctx, f.Project, f.Instance, cCfg, option.WithTokenSource(ts))
    88  	if err != nil {
    89  		return nil, errors.Annotate(err, "failed to construct BigTable client").Err()
    90  	}
    91  	return &Storage{
    92  		Client:   client,
    93  		LogTable: f.LogTable,
    94  	}, nil
    95  }