Refactor config to return an error instead of aborting

Gododir/main.go

@@ -17,6 +17,14 @@ func parseEnvironment(context *do.Context) string {
 	return environment
 }
 
+func loadConfig(environment string) config.Config {
+	cfg, err := config.NewConfig(environment)
+	if err != nil {
+		log.Fatalf("Error loading config\n%v", err)
+	}
+	return *cfg
+}
+
 func tasks(p *do.Project) {
 
 	p.Task("run", nil, func(context *do.Context) {
@@ -37,7 +45,7 @@ func tasks(p *do.Project) {
 
 	p.Task("migrate", nil, func(context *do.Context) {
 		environment := parseEnvironment(context)
-		cfg := config.NewConfig(environment)
+		cfg := loadConfig(environment)
 		connectString := config.DbConnectionString(cfg.Database)
 		migrate := fmt.Sprintf("migrate -database '%s' -path ./db/migrations up", connectString)
 		dumpSchema := fmt.Sprintf("pg_dump -O -s %s > ./db/schema.sql", cfg.Database.Name)
@@ -47,7 +55,7 @@ func tasks(p *do.Project) {
 
 	p.Task("rollback", nil, func(context *do.Context) {
 		environment := parseEnvironment(context)
-		cfg := config.NewConfig(environment)
+		cfg := loadConfig(environment)
 		connectString := config.DbConnectionString(cfg.Database)
 		migrate := fmt.Sprintf("migrate -database '%s' -path ./db/migrations down 1", connectString)
 		dumpSchema := fmt.Sprintf("pg_dump -O -s %s > ./db/schema.sql", cfg.Database.Name)

cmd/populate_blocks/main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"flag"
-
 	"log"
 
 	"fmt"
@@ -18,7 +17,10 @@ func main() {
 	environment := flag.String("environment", "", "Environment name")
 	startingBlockNumber := flag.Int("starting-number", -1, "First block to fill from")
 	flag.Parse()
-	cfg := config.NewConfig(*environment)
+	cfg, err := config.NewConfig(*environment)
+	if err != nil {
+		log.Fatalf("Error loading config\n%v", err)
+	}
 
 	blockchain := geth.NewGethBlockchain(cfg.Client.IPCPath)
 	connectString := config.DbConnectionString(cfg.Database)

cmd/run/main.go

@@ -18,7 +18,10 @@ import (
 func main() {
 	environment := flag.String("environment", "", "Environment name")
 	flag.Parse()
-	cfg := config.NewConfig(*environment)
+	cfg, err := config.NewConfig(*environment)
+	if err != nil {
+		log.Fatalf("Error loading config\n%v", err)
+	}
 
 	fmt.Println("Client Path ", cfg.Client.IPCPath)
 	blockchain := geth.NewGethBlockchain(cfg.Client.IPCPath)

integration_test/geth_blockchain_test.go

@@ -18,7 +18,7 @@ var _ = Describe("Reading from the Geth blockchain", func() {
 
 	BeforeEach(func() {
 		observer = fakes.NewFakeBlockchainObserver()
-		cfg := config.NewConfig("private")
+		cfg, _ := config.NewConfig("private")
 		blockchain = geth.NewGethBlockchain(cfg.Client.IPCPath)
 		observers := []core.BlockchainObserver{observer}
 		listener = blockchain_listener.NewBlockchainListener(blockchain, observers)

pkg/config/config.go

@@ -11,6 +11,8 @@ import (
 	"path"
 	"runtime"
 
+	"errors"
+
 	"github.com/BurntSushi/toml"
 )
 
@@ -19,14 +21,22 @@ type Config struct {
 	Client   Client
 }
 
-func NewConfig(environment string) Config {
+var NewErrConfigFileNotFound = func(environment string) error {
+	return errors.New(fmt.Sprintf("No configuration found for environment: %v", environment))
+}
+
+func NewConfig(environment string) (*Config, error) {
 	filenameWithExtension := fmt.Sprintf("%s.toml", environment)
 	absolutePath := filepath.Join(ProjectRoot(), "pkg", "config", "environments", filenameWithExtension)
-	config := parseConfigFile(absolutePath)
+	config, err := parseConfigFile(absolutePath)
-	if !filepath.IsAbs(config.Client.IPCPath) {
+	if err != nil {
-		config.Client.IPCPath = filepath.Join(ProjectRoot(), config.Client.IPCPath)
+		return nil, NewErrConfigFileNotFound(environment)
+	} else {
+		if !filepath.IsAbs(config.Client.IPCPath) {
+			config.Client.IPCPath = filepath.Join(ProjectRoot(), config.Client.IPCPath)
+		}
+		return config, nil
 	}
-	return config
 }
 
 func ProjectRoot() string {
@@ -34,15 +44,15 @@ func ProjectRoot() string {
 	return path.Join(path.Dir(filename), "..", "..")
 }
 
-func parseConfigFile(configfile string) Config {
+func parseConfigFile(filePath string) (*Config, error) {
 	var cfg Config
-	_, err := os.Stat(configfile)
+	_, err := os.Stat(filePath)
 	if err != nil {
-		log.Fatal("Config file is missing: ", configfile)
+		return nil, err
+	} else {
+		if _, err := toml.DecodeFile(filePath, &cfg); err != nil {
+			log.Fatal(err)
+		}
+		return &cfg, err
 	}
-
-	if _, err := toml.DecodeFile(configfile, &cfg); err != nil {
-		log.Fatal(err)
-	}
-	return cfg
 }

pkg/config/config_test.go

@@ -11,8 +11,9 @@ import (
 var _ = Describe("Loading the config", func() {
 
 	It("reads the private config using the environment", func() {
-		privateConfig := config.NewConfig("private")
+		privateConfig, err := config.NewConfig("private")
 
+		Expect(err).To(BeNil())
 		Expect(privateConfig.Database.Hostname).To(Equal("localhost"))
 		Expect(privateConfig.Database.Name).To(Equal("vulcanize_private"))
 		Expect(privateConfig.Database.Port).To(Equal(5432))
@@ -20,4 +21,11 @@ var _ = Describe("Loading the config", func() {
 		Expect(privateConfig.Client.IPCPath).To(Equal(expandedPath))
 	})
 
+	It("returns an error when there is no matching config file", func() {
+		config, err := config.NewConfig("bad-config")
+
+		Expect(config).To(BeNil())
+		Expect(err).NotTo(BeNil())
+	})
+
 })

pkg/repositories/postgres.go

@@ -6,6 +6,7 @@ import (
 	"context"
 
 	"errors"
+
 	"github.com/8thlight/vulcanizedb/pkg/core"
 	"github.com/jmoiron/sqlx"
 	_ "github.com/lib/pq"

pkg/repositories/repository_test.go

@@ -217,7 +217,8 @@ var _ = Describe("Repositories", func() {
 
 	Describe("Postgres repository", func() {
 		It("connects to the database", func() {
-			pgConfig := config.DbConnectionString(config.NewConfig("private").Database)
+			cfg, _ := config.NewConfig("private")
+			pgConfig := config.DbConnectionString(cfg.Database)
 			db, err := sqlx.Connect("postgres", pgConfig)
 			Expect(err).Should(BeNil())
 			Expect(db).ShouldNot(BeNil())
@@ -232,7 +233,8 @@ var _ = Describe("Repositories", func() {
 				Nonce:        badNonce,
 				Transactions: []core.Transaction{},
 			}
-			pgConfig := config.DbConnectionString(config.NewConfig("private").Database)
+			cfg, _ := config.NewConfig("private")
+			pgConfig := config.DbConnectionString(cfg.Database)
 			db, _ := sqlx.Connect("postgres", pgConfig)
 			Expect(db).ShouldNot(BeNil())
 			repository := repositories.NewPostgres(db)
@@ -249,7 +251,8 @@ var _ = Describe("Repositories", func() {
 			//badHash violates db To field length
 			badHash := fmt.Sprintf("x %s", strings.Repeat("1", 100))
 			badTransaction := core.Transaction{To: badHash}
-			pgConfig := config.DbConnectionString(config.NewConfig("private").Database)
+			cfg, _ := config.NewConfig("private")
+			pgConfig := config.DbConnectionString(cfg.Database)
 			block := core.Block{
 				Number:       123,
 				Transactions: []core.Transaction{badTransaction},
@@ -266,7 +269,8 @@ var _ = Describe("Repositories", func() {
 		})
 
 		AssertRepositoryBehavior(func() repositories.Repository {
-			pgConfig := config.DbConnectionString(config.NewConfig("private").Database)
+			cfg, _ := config.NewConfig("private")
+			pgConfig := config.DbConnectionString(cfg.Database)
 			db, _ := sqlx.Connect("postgres", pgConfig)
 			db.MustExec("DELETE FROM transactions")
 			db.MustExec("DELETE FROM blocks")