Adding internal/config/builder.go

internal/config/builder.go

@@ -0,0 +1,102 @@
+package config
+
+import (
+	"errors"
+	"io"
+	"os"
+
+	"github.com/mitchellh/mapstructure"
+	"github.com/spf13/pflag"
+	"github.com/spf13/viper"
+)
+
+// This is a simple module that encapsulate the creation
+// of a config object and can override values from cli flags.
+
+type Builder struct {
+	in    io.Reader
+	flags *pflag.FlagSet
+	binds map[string]string
+}
+
+func NewBuilder() *Builder {
+	return &Builder{
+		binds: map[string]string{},
+	}
+}
+
+// Set the config file to read
+func (b *Builder) SetConfigFile(filename string) *Builder {
+	file, _ := os.Open(filename)
+	return b.SetSource(file)
+}
+
+// Set the source to read
+func (b *Builder) SetSource(in io.Reader) *Builder {
+	b.in = in
+	return b
+}
+
+// Set all flags that the builder should use.
+func (b *Builder) SetFlags(flags *pflag.FlagSet) *Builder {
+	b.flags = flags
+	return b
+}
+
+// Add a flag to the builder.
+func (b *Builder) AddFlag(flag *pflag.Flag) *Builder {
+	b.flags.AddFlag(flag)
+	return b
+}
+
+// Build the config object from file, cli-flags
+func (b *Builder) Build() (*Config, error) {
+	if b.in == nil {
+		return nil, errors.New("Config not set")
+	}
+
+	conf := New()
+
+	v := viper.New()
+	v.SetConfigType("yaml")
+
+	if b.flags != nil {
+		// bind flags in viper.
+		for key, flagname := range b.binds {
+			flag := b.flags.Lookup(flagname)
+			if flag == nil {
+				continue
+			}
+
+			if err := v.BindPFlag(key, flag); err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	// Read config and unmarshal
+	if err := v.ReadConfig(b.in); err != nil {
+		return nil, err
+	}
+
+	decoders := mapstructure.ComposeDecodeHookFunc(
+		mapstructure.TextUnmarshallerHookFunc(),
+		mapstructure.StringToTimeDurationHookFunc(),
+		mapstructure.StringToSliceHookFunc(","),
+		decodeShorthandShipConfig,
+	)
+
+	err := v.Unmarshal(&conf, viper.DecodeHook(decoders))
+	if err != nil {
+		return nil, err
+	}
+
+	// Call custom handler.
+	if b.flags != nil {
+		if err := conf.ReadCliFlags(b.flags); err != nil {
+			return nil, err
+		}
+	}
+
+	return &conf, nil
+}

internal/config/builder_test.go

@@ -0,0 +1,151 @@
+package config
+
+import (
+	"bytes"
+	"testing"
+	"time"
+
+	"github.com/eosswedenorg/thalos/internal/log"
+	"github.com/spf13/pflag"
+	"github.com/stretchr/testify/require"
+
+	shipclient "github.com/eosswedenorg-go/antelope-ship-client"
+)
+
+func TestBuilder(t *testing.T) {
+	expected := Config{
+		Name:         "ship-reader-1",
+		Api:          "http://127.0.0.1:8080",
+		MessageCodec: "mojibake",
+		Log: log.Config{
+			Filename:    "some_file.log",
+			Directory:   "/path/to/whatever",
+			MaxFileSize: 200,
+			MaxTime:     30 * time.Minute,
+		},
+		Ship: ShipConfig{
+			Url:                 "127.0.0.1:8089",
+			StartBlockNum:       23671836,
+			EndBlockNum:         23872222,
+			IrreversibleOnly:    true,
+			MaxMessagesInFlight: 1337,
+		},
+		Telegram: TelegramConfig{
+			Id:      "110201543:AAHdqTcvCH1vGWJxfSeofSAs0K5PALDsaw",
+			Channel: -123456789,
+		},
+		Redis: RedisConfig{
+			Addr:     "localhost:6379",
+			User:     "myuser",
+			Password: "passwd",
+			DB:       4,
+			Prefix:   "some::ship",
+		},
+	}
+
+	builder := NewBuilder()
+	builder.SetSource(bytes.NewBuffer([]byte(`
+name: "ship-reader-1"
+api: "http://127.0.0.1:8080"
+message_codec: "mojibake"
+log:
+  filename: some_file.log
+  directory: /path/to/whatever
+  maxtime: 30m
+  maxfilesize: 200b
+ship:
+  url: "127.0.0.1:8089"
+  irreversible_only: true
+  max_messages_in_flight: 1337
+  start_block_num: 23671836
+  end_block_num: 23872222
+telegram:
+  id: "110201543:AAHdqTcvCH1vGWJxfSeofSAs0K5PALDsaw"
+  channel: -123456789
+redis:
+  addr: "localhost:6379"
+  user: "myuser"
+  password: "passwd"
+  db: 4
+  prefix: "some::ship"
+`)))
+
+	cfg, err := builder.Build()
+
+	require.NoError(t, err)
+	require.Equal(t, &expected, cfg)
+}
+
+func TestBuilder_NilSource(t *testing.T) {
+	cfg, err := NewBuilder().Build()
+	require.Nil(t, cfg)
+	require.EqualError(t, err, "Config not set")
+}
+
+func TestBuilder_WithShorthandShipUrl(t *testing.T) {
+	expected := Config{
+		Name:         "ship-reader-1",
+		Api:          "http://127.0.0.1:8080",
+		MessageCodec: "json",
+		Log: log.Config{
+			MaxFileSize: 10 * 1000 * 1000, // 10 mb
+			MaxTime:     time.Hour * 24,
+		},
+		Ship: ShipConfig{
+			Url:                 "127.0.0.1:8089",
+			StartBlockNum:       shipclient.NULL_BLOCK_NUMBER,
+			EndBlockNum:         shipclient.NULL_BLOCK_NUMBER,
+			MaxMessagesInFlight: 10,
+			IrreversibleOnly:    false,
+		},
+		Telegram: TelegramConfig{
+			Id:      "110201543:AAHdqTcvCH1vGWJxfSeofSAs0K5PALDsaw",
+			Channel: -123456789,
+		},
+		Redis: RedisConfig{
+			Addr:     "localhost:6379",
+			Password: "passwd",
+			DB:       4,
+			Prefix:   "some::ship",
+		},
+	}
+
+	builder := NewBuilder()
+	builder.SetSource(bytes.NewBuffer([]byte(`
+name: "ship-reader-1"
+api: "http://127.0.0.1:8080"
+ship: "127.0.0.1:8089"
+telegram:
+  id: "110201543:AAHdqTcvCH1vGWJxfSeofSAs0K5PALDsaw"
+  channel: -123456789
+redis:
+  addr: "localhost:6379"
+  password: "passwd"
+  db: 4
+  prefix: "some::ship"
+`)))
+
+	cfg, err := builder.Build()
+
+	require.NoError(t, err)
+	require.Equal(t, &expected, cfg)
+}
+
+func TestBuilder_Flags(t *testing.T) {
+	flags := pflag.FlagSet{}
+	flags.StringP("log", "l", "", "")
+
+	require.NoError(t, flags.Set("log", "/path/to/logs"))
+
+	cfg, err := NewBuilder().
+		SetSource(bytes.NewReader([]byte(``))).
+		SetFlags(&flags).
+		Build()
+
+	expected := New()
+	expected.Log.Filename = "logs"
+	expected.Log.Directory = "/path/to"
+
+	require.NoError(t, err)
+	require.Equal(t, &expected, cfg)
+}