LogDog: Use luci_config/server packages for config

logdog/server/service/config/flag.go

-// Copyright 2016 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 config
-
-import (
-        "errors"
-        "flag"
-        "fmt"
-        "net/http"
-        "net/url"
-        "time"
-
-        "github.com/luci/luci-go/common/clock/clockflag"
-        "github.com/luci/luci-go/common/config"
-        "github.com/luci/luci-go/common/config/impl/filesystem"
-        "github.com/luci/luci-go/common/config/impl/remote"
-        "github.com/luci/luci-go/common/proto/google"
-        "github.com/luci/luci-go/logdog/api/endpoints/coordinator/services/v1"
-        "golang.org/x/net/context"
-)
-
-// Flags is the set of command-line flags used to configure a service.
-type Flags struct {
-        // ConfigFilePath is the path within the ConfigSet of the configuration.
-        //
-        // If ConfigURL is empty, this will be interpreted as a local filesystem path
-        // from which the configuration should be loaded.
-        ConfigFilePath string
-
-        // KillCheckInterval, if >0, starts a goroutine that polls every interval to
-        // see if the configuration has changed.
-        KillCheckInterval clockflag.Duration
-
-        // RoundTripper, if not nil, is the http.RoundTripper that will be used to
-        // fetch remote configurations.
-        RoundTripper http.RoundTripper
-}
-
-// AddToFlagSet augments the supplied FlagSet with values for Flags.
-func (f *Flags) AddToFlagSet(fs *flag.FlagSet) {
-        fs.StringVar(&f.ConfigFilePath, "config-file-path", "",
-                "If set, load configuration from a local filesystem rooted here.")
-        fs.Var(&f.KillCheckInterval, "config-kill-interval",
-                "If non-zero, poll for configuration changes and kill the application if one is detected.")
-}
-
-// CoordinatorOptions returns an Options instance loaded from the supplied flags
-// and Coordinator instance.
-func (f *Flags) CoordinatorOptions(c context.Context, client logdog.ServicesClient) (*Options, error) {
-        ccfg, err := client.GetConfig(c, &google.Empty{})
-        if err != nil {
-                return nil, err
-        }
-
-        // If a ConfigFilePath was specified, use a mock configuration service that
-        // loads from a local file.
-        var ci config.Interface
-        if f.ConfigFilePath != "" {
-                var err error
-                ci, err = filesystem.New(f.ConfigFilePath)
-                if err != nil {
-                        return nil, err
-                }
-        } else {
-                host := ccfg.ConfigServiceHost
-                if host == "" {
-                        if ccfg.ConfigServiceUrl == "" {
-                                return nil, errors.New("coordinator does not specify a config service")
-                        }
-                        u, err := url.Parse(ccfg.ConfigServiceUrl)
-                        if err != nil {
-                                return nil, fmt.Errorf("failed to parse config service URL: %v", err)
-                        }
-                        host = u.Host
-                }
-                if ccfg.ConfigSet == "" {
-                        return nil, errors.New("coordinator does not specify a config set")
-                }
-                if ccfg.ServiceConfigPath == "" {
-                        return nil, errors.New("coordinator does not specify a config path")
-                }
-
-                var clientFactory remote.ClientFactory
-                if f.RoundTripper != nil {
-                        rr := f.RoundTripper
-                        clientFactory = func(context.Context) (*http.Client, error) {
-                                return &http.Client{Transport: rr}, nil
-                        }
-                }
-                ci = remote.New(host, false, clientFactory)
-        }
-
-        return &Options{
-                Config:            ci,
-                ConfigSet:         ccfg.ConfigSet,
-                ServiceConfigPath: ccfg.ServiceConfigPath,
-                KillCheckInterval: time.Duration(f.KillCheckInterval),
-        }, nil
-}