Move config specific functions to their own package

google · May 17, 2017 · 8b48ccf · 8b48ccf
1 parent d0c7380
commit 8b48ccf
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Showing 5 changed files with 102 additions and 61 deletions.
diff --git a/configs/configs.go b/configs/configs.go
@@ -0,0 +1,64 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package configs
+
+import (
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"time"
+)
+
+// JSONDuration is an abstraction used to simplifying unmarshalling
+// json into structs that contain time.Duration fields. Expected
+// format is the same as provided to time.ParseDuration.
+type JSONDuration struct {
+	time.Duration
+}
+
+// UnmarshalJSON parses a time.Duration field from a string
+func (jd *JSONDuration) UnmarshalJSON(data []byte) error {
+	s := ""
+	err := json.Unmarshal(data, &s)
+	if err != nil {
+		return err
+	}
+	d, err := time.ParseDuration(s)
+	if err != nil {
+		return err
+	}
+	jd.Duration = d
+	return nil
+}
+
+// LoadConfig loads a configuration JSON file from the provided path and
+// unmarshals it into the provided object. It also enforces --config being
+// the only flag provided to the binary calling LoadConfig.
+func LoadConfig(path string, obj interface{}) error {
+	// Only allow either --config OR any other flags
+	if flag.CommandLine.NFlag() > 1 {
+		return errors.New("Cannot use --config with any other flags")
+	}
+	f, err := ioutil.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("Failed to read config file: %v", err)
+	}
+	if err := json.Unmarshal(f, obj); err != nil {
+		return fmt.Errorf("Failed to parse config file: %v", err)
+	}
+	return nil
+}
diff --git a/util/config.go → configs/configs_test.go b/util/config.go → configs/configs_test.go
@@ -12,30 +12,34 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package util
+package configs
 
 import (
 	"encoding/json"
+	"testing"
 	"time"
 )
 
-// ConfigDuration is an abstraction used to simplifying unmarshalling
-// json into structs that contain time.Duration fields
-type ConfigDuration struct {
-	time.Duration
-}
+func TestJSONDuration(t *testing.T) {
+	var s struct {
+		Dur JSONDuration
+	}
+
+	a := []byte(`{"dur":"10s"}`)
+	if err := json.Unmarshal(a, &s); err != nil {
+		t.Errorf("Failed to unmarshal duration: %v", err)
+	}
+	if s.Dur.Duration != (time.Second * 10) {
+		t.Errorf("Unexpected duration, want: 10s, got: %s", s.Dur)
+	}
 
-// UnmarshalJSON parses a time.Duration field from a string
-func (cd ConfigDuration) UnmarshalJSON(data []byte) error {
-	s := ""
-	err := json.Unmarshal(data, &s)
-	if err != nil {
-		return err
+	b := []byte(`{"dur": 1}`)
+	if err := json.Unmarshal(b, &s); err == nil {
+		t.Error("Didn't fail when unmarshalling a non-string type into JSONDuration")
 	}
-	d, err := time.ParseDuration(s)
-	if err != nil {
-		return err
+
+	c := []byte(`{"dur": ""}`)
+	if err := json.Unmarshal(c, &s); err == nil {
+		t.Error("Didn't fail when unmarshalling an empty string into JSONDuration")
 	}
-	cd.Duration = d
-	return nil
 }
diff --git a/examples/ct/ct_server/main.go b/examples/ct/ct_server/main.go
@@ -15,11 +15,9 @@
 package main
 
 import (
-	"encoding/json"
 	_ "expvar"
 	"flag" // For HTTP server registration
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"os"
 	"strings"
@@ -30,6 +28,7 @@ import (
 	etcdnaming "github.com/coreos/etcd/clientv3/naming"
 	"github.com/golang/glog"
 	"github.com/google/trillian"
+	"github.com/google/trillian/configs"
 	"github.com/google/trillian/examples/ct"
 	"github.com/google/trillian/util"
 	"google.golang.org/grpc"
@@ -40,7 +39,7 @@ type config struct {
 	Host                 string
 	Port                 int
 	LogRPCServer         string
-	RPCDeadline          util.ConfigDuration
+	RPCDeadline          configs.JSONDuration
 	LogConfig            string
 	MaxGetEntriesAllowed int64
 	EtcdServers          string
@@ -60,16 +59,8 @@ func main() {
 	flag.Parse()
 
 	if *configFlag != "" {
-		// Only allow either --configFlag OR any other flags
-		if flag.CommandLine.NFlag() > 2 {
-			glog.Exit("Cannot use --configFlag with any other flags")
-		}
-		f, err := ioutil.ReadFile(*configFlag)
-		if err != nil {
-			glog.Exitf("Failed to read config file: %v", err)
-		}
-		if err := json.Unmarshal(f, &c); err != nil {
-			glog.Exitf("Failed to parse config file: %v", err)
+		if err := configs.LoadConfig(*configFlag, &c); err != nil {
+			glog.Exit(err)
 		}
 	}
 

diff --git a/server/trillian_log_server/main.go b/server/trillian_log_server/main.go
@@ -16,9 +16,7 @@ package main
 
 import (
 	"context"
-	"encoding/json"
 	"flag"
-	"io/ioutil"
 	_ "net/http/pprof"
 	"strings"
 	"time"
@@ -29,6 +27,7 @@ import (
 	etcdnaming "github.com/coreos/etcd/clientv3/naming"
 	"github.com/golang/glog"
 	"github.com/google/trillian"
+	"github.com/google/trillian/configs"
 	"github.com/google/trillian/crypto/keys"
 	"github.com/google/trillian/extension"
 	"github.com/google/trillian/monitoring"
@@ -46,7 +45,7 @@ type config struct {
 	MySQLURI            string
 	RPCEndpoint         string
 	HTTPEndpoint        string
-	DumpMetricsInterval util.ConfigDuration
+	DumpMetricsInterval configs.JSONDuration
 	EtcdServers         string
 	EtcdService         string
 }
@@ -64,16 +63,8 @@ func main() {
 	flag.Parse()
 
 	if *configFlag != "" {
-		// Only allow either --configFlag OR any other flags
-		if flag.CommandLine.NFlag() > 2 {
-			glog.Exit("Cannot use --configFlag with any other flags")
-		}
-		f, err := ioutil.ReadFile(*configFlag)
-		if err != nil {
-			glog.Exitf("Failed to read config file: %v", err)
-		}
-		if err := json.Unmarshal(f, &c); err != nil {
-			glog.Exitf("Failed to parse config file: %v", err)
+		if err := configs.LoadConfig(*configFlag, &c); err != nil {
+			glog.Exit(err)
 		}
 	}
 

diff --git a/server/trillian_log_signer/main.go b/server/trillian_log_signer/main.go
@@ -15,16 +15,15 @@
 package main
 
 import (
-	"encoding/json"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"time"
 
 	_ "github.com/go-sql-driver/mysql" // Load MySQL driver
 
 	"github.com/golang/glog"
+	"github.com/google/trillian/configs"
 	"github.com/google/trillian/crypto/keys"
 	"github.com/google/trillian/extension"
 	"github.com/google/trillian/monitoring/metric"
@@ -39,17 +38,17 @@ import (
 type config struct {
 	MySQLURI             string
 	HTTPEndpoint         string
-	SequencerInterval    util.ConfigDuration
+	SequencerInterval    configs.JSONDuration
 	BatchSize            int
 	NumSequencers        int
-	SequencerGuardWindow util.ConfigDuration
-	DumpMetricsInterval  util.ConfigDuration
+	SequencerGuardWindow configs.JSONDuration
+	DumpMetricsInterval  configs.JSONDuration
 	ForceMaster          bool
 	EtcdServers          string
 	LockFilePath         string
-	PreElectionPause     util.ConfigDuration
-	MasterCheckInterval  util.ConfigDuration
-	MasterHoldInterval   util.ConfigDuration
+	PreElectionPause     configs.JSONDuration
+	MasterCheckInterval  configs.JSONDuration
+	MasterHoldInterval   configs.JSONDuration
 	ResignOdds           int
 }
 
@@ -75,16 +74,8 @@ func main() {
 	flag.Parse()
 
 	if *configFlag != "" {
-		// Only allow either --configFlag OR any other flags
-		if flag.CommandLine.NFlag() > 2 {
-			glog.Exit("Cannot use --configFlag with any other flags")
-		}
-		f, err := ioutil.ReadFile(*configFlag)
-		if err != nil {
-			glog.Exitf("Failed to read config file: %v", err)
-		}
-		if err := json.Unmarshal(f, &c); err != nil {
-			glog.Exitf("Failed to parse config file: %v", err)
+		if err := configs.LoadConfig(*configFlag, &c); err != nil {
+			glog.Exit(err)
 		}
 	}