Add server/cache support to gaeconfig.

logdog/appengine/coordinator/config/projects.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.
 
 package config
 
 import (
         "fmt"
-        "strings"
+        "sort"
 
-        "github.com/golang/protobuf/proto"
         "github.com/luci/gae/service/info"
-        "github.com/luci/luci-go/common/config"
+        ccfg "github.com/luci/luci-go/common/config"
         log "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/logdog/api/config/svcconfig"
+        "github.com/luci/luci-go/server/config"
+        "github.com/luci/luci-go/server/config/textproto"
+
         "golang.org/x/net/context"
 )
 
-const maxProjectWorkers = 32
-
 // ProjectConfigPath returns the path of the project-specific configuration.
 // This path should be used with a project config set.
 //
 // A given project's configuration is named after the current App ID.
 func ProjectConfigPath(c context.Context) string {
         return fmt.Sprintf("%s.cfg", info.AppID(c))
 }
 
 // ProjectConfig loads the project config protobuf from the config service.
 //
 // This function will return:
 //      - nil, if the project exists and the configuration successfully loaded
 //      - config.ErrNoConfig if the project configuration was not present.
 //      - ErrInvalidConfig if the project configuration was present, but could not
 //        be loaded.
 //      - Some other error if an error occurred that does not fit one of the
 //        previous categories.
-func ProjectConfig(c context.Context, project config.ProjectName) (*svcconfig.ProjectConfig, error) {
+func ProjectConfig(c context.Context, project ccfg.ProjectName) (*svcconfig.ProjectConfig, error) {
         if project == "" {
                 return nil, config.ErrNoConfig
         }
 
         // Get the config from the config service. If the configuration doesn't exist,
         // this will return config.ErrNoConfig.
         configSet, configPath := config.ProjectConfigSet(project), ProjectConfigPath(c)
-        cfg, err := config.GetConfig(c, configSet, configPath, false)
-        if err != nil {
+
+        var pcfg svcconfig.ProjectConfig
+        if err := config.Get(c, config.AsService, configSet, configPath, textproto.Message(&pcfg), nil); err != nil {
                 log.Fields{
                         log.ErrorKey: err,
                         "project":    project,
                         "configSet":  configSet,
                         "configPath": configPath,
                 }.Errorf(c, "Failed to load project configuration content.")
                 return nil, err
         }
-
-        pcfg, err := unmarshalProjectConfig(cfg)
-        if err != nil {
-                log.Fields{
-                        log.ErrorKey:  err,
-                        "project":     project,
-                        "configSet":   cfg.ConfigSet,
-                        "path":        cfg.Path,
-                        "contentHash": cfg.ContentHash,
-                }.Errorf(c, "Failed to unmarshal project configuration.")
-                return nil, ErrInvalidConfig
-        }
-        return pcfg, nil
+        return &pcfg, nil
 }
 
-// AllProjectConfigs returns the project configurations for all projects that
-// have a configuration.
-//
-// If a project's configuration fails to load, an error will be logged and the
-// project will be omitted from the output map.
-func AllProjectConfigs(c context.Context) (map[config.ProjectName]*svcconfig.ProjectConfig, error) {
-        // TODO: This endpoint is generally slow. Even though there is memcache-based
-        // config cache, this really should be loaded from a more failsafe cache like
-        // datastore to protect against config service outages.
-        configs, err := config.GetProjectConfigs(c, ProjectConfigPath(c), false)
-        if err != nil {
+// ProjectNames returns a sorted list of the names of all of the projects
+// that the supplied authority can view.
+func ProjectNames(c context.Context, a config.Authority) ([]ccfg.ProjectName, error) {
+        configPath := ProjectConfigPath(c)
+
+        var metas []*config.Meta
+        if err := config.GetAll(c, a, config.Project, configPath, nil, &metas); err != nil {
                 log.WithError(err).Errorf(c, "Failed to load project configs.")
                 return nil, err
         }
 
-        result := make(map[config.ProjectName]*svcconfig.ProjectConfig, len(configs))
-        for _, cfg := range configs {
-                // Identify the project by removng the "projects/" prefix.
-                project := config.ProjectName(strings.TrimPrefix(cfg.ConfigSet, "projects/"))
-                if err := project.Validate(); err != nil {
-                        log.Fields{
-                                log.ErrorKey: err,
-                                "configSet":  cfg.ConfigSet,
-                        }.Errorf(c, "Invalid project name returned.")
-                        continue
+        // Iterate through our Metas and extract the project names.
+        projects := make([]ccfg.ProjectName, 0, len(metas))
+        for _, meta := range metas {
+                projectName, _, _ := config.ParseProjectConfigSet(meta.ConfigSet)
+                if projectName != "" {
+                        projects = append(projects, projectName)
                 }
-
-                // Unmarshal the project's configuration.
-                pcfg, err := unmarshalProjectConfig(&cfg)
-                if err != nil {
-                        log.Fields{
-                                log.ErrorKey:  err,
-                                "configSet":   cfg.ConfigSet,
-                                "path":        cfg.Path,
-                                "contentHash": cfg.ContentHash,
-                        }.Errorf(c, "Failed to unmarshal project configuration.")
-                        continue
-                }
-
-                result[project] = pcfg
         }
-        return result, nil
+        sort.Sort(projectNameSlice(projects))
+        return projects, nil
 }
 
-func unmarshalProjectConfig(cfg *config.Config) (*svcconfig.ProjectConfig, error) {
-        var pcfg svcconfig.ProjectConfig
-        if err := proto.UnmarshalText(cfg.Content, &pcfg); err != nil {
-                return nil, err
-        }
-        return &pcfg, nil
+// ActiveProjects returns a full list of all config service projects with
+// LogDog project configurations.
+//
+// The list will be alphabetically sorted.
+func ActiveProjects(c context.Context) ([]ccfg.ProjectName, error) {
+        return ProjectNames(c, config.AsService)
 }
+
+// ActiveUserProjects returns a full list of all config service projects with
+// LogDog project configurations that the current user can see.
+//
+// The list will be alphabetically sorted.
+func ActiveUserProjects(c context.Context) ([]ccfg.ProjectName, error) {
+        return ProjectNames(c, config.AsUser)
+}
+
+type projectNameSlice []ccfg.ProjectName
+
+func (s projectNameSlice) Len() int           { return len(s) }
+func (s projectNameSlice) Less(i, j int) bool { return s[i] < s[j] }
+func (s projectNameSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }