fix: allow elasticsearch settings to be read from ENV vars if no defa…

…ults are defined within yaml files

For more information see: spf13/viper#761

Makefile

@@ -14,7 +14,11 @@ integration:
 
 .PHONY: humantest
 humantest:
-	LOG_HUMAN=true richgo test -v -p=1 -timeout=60s $(PKGS)
+ifndef run
+	LOG_DEBUG=true LOG_HUMAN=true richgo test -v -p=1 -timeout=60s $(PKGS)
+else
+	LOG_DEBUG=true LOG_HUMAN=true richgo test -v -p=1 -timeout=60s $(PKGS) -run $(run)
+endif
 
 .PHONY: coverage
 coverage:

config.go

@@ -58,7 +58,7 @@ func LoadConfig(log zerolog.Logger, dir string, env string) (*viper.Viper, error
 	}
 
 	// Viper ignores environment variables when unmarshalling if no defaults are set.
-	// This should that, see also https://github.com/spf13/viper/issues/188
+	// This should fix that in some scenarios, see also https://github.com/spf13/viper/issues/188
 	for _, key := range v.AllKeys() {
 		val := v.Get(key)
 		v.Set(key, val)

config_test.go

@@ -63,4 +63,6 @@ func TestConfig_OverrideEnvVariables(t *testing.T) {
 	err = cfg.Sub("vars").Unmarshal(cfgStruct)
 	assert.Nil(t, err)
 	assert.Equal(t, "from-env", cfgStruct.Filename)
+
+	os.Clearenv()
 }

docker-compose.yml

@@ -14,7 +14,7 @@ services:
       - "5432:5432"
 
   elasticsearch:
-    image: docker.elastic.co/elasticsearch/elasticsearch:7.12.0
+    image: docker.elastic.co/elasticsearch/elasticsearch:7.14.1
     environment:
       - bootstrap.memory_lock=true
       - discovery.type=single-node

elasticsearch.go

@@ -44,15 +44,13 @@ func (s *Elasticsearch) Name() string {
 func (s *Elasticsearch) Configure(ctx *AppEnv) error {
 	s.log = ctx.Log
 
-	// unmarshal config and set defaults
-	s.Config = &elasticsearch7.Config{}
-
-	if !ctx.Config.InConfig("elasticsearch") {
-		return errMissingElasticsearchConfig
-	}
-
-	if err := ctx.Config.Sub("elasticsearch").Unmarshal(&s.Config); err != nil {
-		return fmt.Errorf("parsing elasticsearch configuration: %w", err)
+	// Fetch config from viper. Avoid unmarshal directly into elasticsearch7.Config
+	// as it doesn't work with env vars:
+	// https://github.com/spf13/viper/issues/761
+	s.Config = &elasticsearch7.Config{
+		Addresses: ctx.Config.GetStringSlice("elasticsearch.addresses"),
+		Username:  ctx.Config.GetString("elasticsearch.username"),
+		Password:  ctx.Config.GetString("elasticsearch.password"),
 	}
 
 	if len(s.Config.Addresses) == 0 {

elasticsearch_test.go

@@ -2,6 +2,7 @@ package goboot_test
 
 import (
 	"context"
+	"os"
 	"testing"
 
 	"github.com/nielskrijger/goboot"
@@ -32,10 +33,18 @@ func TestElasticsearch_Success(t *testing.T) {
 	assert.NotNil(t, s.Config)
 }
 
-func TestElasticsearch_ErrorMissingConfig(t *testing.T) {
+func TestElasticsearch_SuccessEnvs(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test")
+	}
+
 	s := &goboot.Elasticsearch{}
-	err := s.Configure(goboot.NewAppEnv("./testdata/elasticsearch", ""))
-	assert.EqualError(t, err, "missing \"elasticsearch\" configuration")
+	_ = os.Setenv("ELASTICSEARCH_USERNAME", "elastic")
+	_ = os.Setenv("ELASTICSEARCH_PASSWORD", "secret")
+
+	err := s.Configure(goboot.NewAppEnv("./testdata/elasticsearch", "using-env-vars"))
+	assert.Nil(t, err)
+	os.Clearenv()
 }
 
 func TestElasticsearch_ErrorNoAddresses(t *testing.T) {

testdata/elasticsearch/config.using-env-vars.yaml

@@ -0,0 +1,3 @@
+elasticsearch:
+  addresses:
+    - http://localhost:9200