gddo-server: add server.configPoller
A config poller is added to the server, which polls for config data
based on the setting of GDDO_CONFIG_LOCATION.
Change-Id: Ib4330c3614a17e32930a09071043e5f2b50e6bf3
Reviewed-on: https://go-review.googlesource.com/c/gddo/+/285932
Trust: Julie Qiu <julie@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/gddo-server/poller.go b/gddo-server/poller.go
new file mode 100644
index 0000000..c209917
--- /dev/null
+++ b/gddo-server/poller.go
@@ -0,0 +1,45 @@
+// Copyright 2021 The Go 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 main
+
+import (
+ "context"
+ "fmt"
+ "os"
+ "time"
+
+ "github.com/golang/gddo/gddo-server/dynconfig"
+ "github.com/golang/gddo/gddo-server/poller"
+ "github.com/golang/gddo/log"
+)
+
+func newConfigPoller(ctx context.Context, pollEvery time.Duration) (_ *poller.Poller, err error) {
+ location := os.Getenv("GDDO_CONFIG_LOCATION")
+ if location == "" {
+ return nil, fmt.Errorf("GDDO_CONFIG_LOCATION is not set")
+ }
+ log.Info(ctx, fmt.Sprintf("GDDO_CONFIG_LOCATION: %q", location))
+
+ log.Info(ctx, fmt.Sprintf("using dynamic config from %s for experiments", location))
+ getter := func(ctx context.Context) (*dynconfig.DynamicConfig, error) {
+ return dynconfig.Read(ctx, location)
+ }
+ initial, err := getter(ctx)
+ // If we can't load the initial state, then fail.
+ if err != nil {
+ return nil, err
+ }
+ p := poller.New(
+ initial,
+ func(ctx context.Context) (interface{}, error) {
+ return getter(ctx)
+ },
+ func(err error) {
+ // Log the error.
+ log.Error(ctx, err.Error())
+ })
+ p.Start(ctx, pollEvery)
+ return p, nil
+}
diff --git a/gddo-server/server.go b/gddo-server/server.go
index 07ebf1f..fdf5ce4 100644
--- a/gddo-server/server.go
+++ b/gddo-server/server.go
@@ -33,6 +33,7 @@
"cloud.google.com/go/trace"
"github.com/golang/gddo/database"
"github.com/golang/gddo/doc"
+ "github.com/golang/gddo/gddo-server/poller"
"github.com/golang/gddo/gosrc"
"github.com/golang/gddo/httputil"
"github.com/golang/gddo/internal/health"
@@ -861,13 +862,14 @@
}
type server struct {
- v *viper.Viper
- db *database.Database
- httpClient *http.Client
- gceLogger *GCELogger
- templates templateMap
- traceClient *trace.Client
- crawlTopic *pubsub.Topic
+ v *viper.Viper
+ db *database.Database
+ httpClient *http.Client
+ gceLogger *GCELogger
+ templates templateMap
+ traceClient *trace.Client
+ crawlTopic *pubsub.Topic
+ configPoller *poller.Poller
statusPNG http.Handler
statusSVG http.Handler
@@ -884,8 +886,12 @@
httpClient: newHTTPClient(v),
importGraphSem: make(chan struct{}, 10),
}
+ cfg, err := newConfigPoller(ctx, 1*time.Millisecond)
+ if err != nil {
+ log.Printf("newConfigPoller: %q", err)
+ }
+ s.configPoller = cfg
- var err error
if proj := s.v.GetString(ConfigProject); proj != "" {
if s.traceClient, err = trace.NewClient(ctx, proj); err != nil {
return nil, err
