config: not properly loaded error (#140)

* config: not properly loaded error

When a wrong config file was used, it result in a panic.
Adding some check condition to validate the Unmarshaled configuration
before using it

fixes #134

* check if datasource is set

* move error locally instead of utils/errors

config/config.go

@@ -15,6 +15,7 @@
 package config
 
 import (
+	"errors"
 	"io/ioutil"
 	"os"
 	"time"
@@ -23,6 +24,9 @@ import (
 	"gopkg.in/yaml.v2"
 )
 
+// ErrDatasourceNotLoaded is returned when the datasource variable in the configuration file is not loaded properly
+var ErrDatasourceNotLoaded = errors.New("could not load configuration: no database source specified")
+
 // File represents a YAML configuration file that namespaces all Clair
 // configuration under the top-level "clair" key.
 type File struct {
@@ -112,6 +116,11 @@ func Load(path string) (config *Config, err error) {
 	}
 	config = &cfgFile.Clair
 
+	if config.Database.Source == "" {
+		err = ErrDatasourceNotLoaded
+		return
+	}
+
 	// Generate a pagination key if none is provided.
 	if config.API.PaginationKey == "" {
 		var key fernet.Key

config/config_test.go

@@ -0,0 +1,81 @@
+package config
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const wrongConfig = `
+dummyKey:
+    wrong:true
+`
+
+const goodConfig = `
+clair:
+  database:
+    source: postgresql://postgres:root@postgres:5432?sslmode=disable
+    cacheSize: 16384
+  api:
+    port: 6060
+    healthport: 6061
+    timeout: 900s
+    paginationKey:
+    servername:
+    cafile:
+    keyfile:
+    certfile:
+  updater:
+    interval: 2h
+  notifier:
+    attempts: 3
+    renotifyInterval: 2h
+    http:
+      endpoint:
+      servername:
+      cafile:
+      keyfile:
+      certfile:
+      proxy:
+`
+
+func TestLoadWrongConfiguration(t *testing.T) {
+	tmpfile, err := ioutil.TempFile("", "clair-config")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer os.Remove(tmpfile.Name()) // clean up
+	if _, err := tmpfile.Write([]byte(wrongConfig)); err != nil {
+		log.Fatal(err)
+	}
+	if err := tmpfile.Close(); err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = Load(tmpfile.Name())
+
+	assert.EqualError(t, err, ErrDatasourceNotLoaded.Error())
+}
+
+func TestLoad(t *testing.T) {
+	tmpfile, err := ioutil.TempFile("", "clair-config")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer os.Remove(tmpfile.Name()) // clean up
+
+	if _, err := tmpfile.Write([]byte(goodConfig)); err != nil {
+		log.Fatal(err)
+	}
+	if err := tmpfile.Close(); err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = Load(tmpfile.Name())
+	assert.NoError(t, err)
+}