Fix failing VCAP_SERVICE credentials check (#4084)

* Fix invalid VCAP_SERVICE credentials check
- Fixes 4081
- When Stratos is deployed via CF and bound to a db service we search VCAP_SERVICE for db credentials
- If we don't find the right properties we fall back on the uri and try to extract them from there
- The check for the right properties was failing due to the following concept
```
fmt.Sprintf("%v", nil) == "<nil>"
```
- Fix is to ensure we pass in better values
Also
- Tidied up and improved logging
- Improved handling of uri reg ex

* Fix backend unit tests

* Fall back on default port of provider

src/jetstream/datastore/database_cf_config.go

@@ -2,6 +2,7 @@ package datastore
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"regexp"
 	"strconv"
@@ -71,21 +72,21 @@ func findDatabaseConfig(vcapServices map[string][]VCAPService, db *DatabaseConfi
 	if len(service.Name) > 0 {
 		dbCredentials := service.Credentials
 
-		log.Infof("Attempting to apply Cloud Foundry database service config from credentials")
+		log.Infof("Attempting to apply Cloud Foundry database service config from VCAP_SERVICES credentials")
 
 		// 1) Check db config in credentials
-		db.Username = fmt.Sprintf("%v", dbCredentials["username"])
-		db.Password = fmt.Sprintf("%v", dbCredentials["password"])
-		db.Host = fmt.Sprintf("%v", dbCredentials["hostname"])
+		db.Username = getDBCredentialsValue(dbCredentials["username"])
+		db.Password = getDBCredentialsValue(dbCredentials["password"])
+		db.Host = getDBCredentialsValue(dbCredentials["hostname"])
 		db.SSLMode = "disable"
-		db.Port, _ = strconv.Atoi(fmt.Sprintf("%v", dbCredentials["port"]))
+		db.Port, _ = strconv.Atoi(getDBCredentialsValue(dbCredentials["port"]))
 		// Note - Both isPostgresService and isMySQLService look at the credentials uri & tags
 		if isPostgresService(service) {
 			db.DatabaseProvider = "pgsql"
-			db.Database = fmt.Sprintf("%v", dbCredentials["dbname"])
+			db.Database = getDBCredentialsValue(dbCredentials["dbname"])
 		} else if isMySQLService(service) {
 			db.DatabaseProvider = "mysql"
-			db.Database = fmt.Sprintf("%v", dbCredentials["name"])
+			db.Database = getDBCredentialsValue(dbCredentials["name"])
 		} else {
 			log.Infof("Cloud Foundry database service contains unsupported db type")
 			return false
@@ -94,18 +95,23 @@ func findDatabaseConfig(vcapServices map[string][]VCAPService, db *DatabaseConfi
 
 		if err != nil {
 			// 2) Check for db config in credentials uri
-			log.Infof("Failed to find required Cloud Foundry database service config, falling back on credential's `%v`", DB_URI)
-			uri := fmt.Sprintf("%v", dbCredentials[DB_URI])
+			log.Infof("Failed to find required Cloud Foundry database service config, falling back on credential's `%v`\n%v", DB_URI, err)
+			uri := getDBCredentialsValue(dbCredentials[DB_URI])
 			if len(uri) == 0 {
 				log.Warnf("Failed to find Cloud Foundry service credential's `%v`", DB_URI)
 				return false
 			}
 
-			db.Username, db.Password, db.Host, db.Port, db.Database = findDatabaseConfigurationFromUri(uri)
-			err := validateRequiredDatabaseParams(db.Username, db.Password, db.Database, db.Host, db.Port)
+			db.Username, db.Password, db.Host, db.Port, db.Database, err = findDatabaseConfigurationFromURI(uri, defaultDBProviderPort(service))
+
+			if err != nil {
+				log.Warnf("Failed to find Cloud Foundry service config from `%v` (failed to parse)", DB_URI)
+				return false
+			}
 
+			err := validateRequiredDatabaseParams(db.Username, db.Password, db.Database, db.Host, db.Port)
 			if err != nil {
-				log.Warnf("Failed to find Cloud Foundry service config's from `%v`", DB_URI)
+				log.Warnf("Failed to find Cloud Foundry service config from `%v` (missing values)\n%v", DB_URI, err)
 				return false
 			}
 		}
@@ -116,6 +122,14 @@ func findDatabaseConfig(vcapServices map[string][]VCAPService, db *DatabaseConfi
 	return false
 }
 
+func getDBCredentialsValue(val interface{}) string {
+	// First ensure that the value is not null, otherwise fmt print will convert to the string "<nil>"
+	if val == nil {
+		val = ""
+	}
+	return fmt.Sprintf("%v", val)
+}
+
 func findDatabaseConfigurations(vcapServices map[string][]VCAPService) map[string]VCAPService {
 	var configs map[string]VCAPService
 	configs = make(map[string]VCAPService)
@@ -133,12 +147,12 @@ func findDatabaseConfigurations(vcapServices map[string][]VCAPService) map[strin
 }
 
 func isPostgresService(service VCAPService) bool {
-	uri := fmt.Sprintf("%v", service.Credentials[DB_URI])
+	uri := getDBCredentialsValue(service.Credentials[DB_URI])
 	return strings.HasPrefix(uri, URI_POSTGRES) || stringInSlice(TAG_POSTGRES, service.Tags)
 }
 
 func isMySQLService(service VCAPService) bool {
-	uri := fmt.Sprintf("%v", service.Credentials[DB_URI])
+	uri := getDBCredentialsValue(service.Credentials[DB_URI])
 	return strings.HasPrefix(uri, URI_MYSQL) || stringInSlice(TAG_MYSQL, service.Tags)
 }
 
@@ -151,10 +165,15 @@ func stringInSlice(a string, list []string) bool {
 	return false
 }
 
-func findDatabaseConfigurationFromUri(uri string) (string, string, string, int, string) {
+func findDatabaseConfigurationFromURI(uri string, defaultPort int) (string, string, string, int, string, error) {
 	re := regexp.MustCompile(`(?P<provider>.+)://(?P<username>[^:]+)(?::(?P<password>.+))?@(?P<host>[^:]+)(?::(?P<port>.+))?\/(?P<dbname>.+)`)
 	n1 := re.SubexpNames()
-	r2 := re.FindAllStringSubmatch(uri, -1)[0]
+	matches := re.FindAllStringSubmatch(uri, -1)
+	if len(matches) < 1 {
+		return "", "", "", 0, "", errors.New("Failed to parse database URI")
+	}
+
+	r2 := matches[0]
 	md := map[string]string{}
 	for i, n := range r2 {
 		md[n1[i]] = n
@@ -163,9 +182,24 @@ func findDatabaseConfigurationFromUri(uri string) (string, string, string, int,
 	username := md["username"]
 	password := md["password"]
 	host := md["host"]
-	port, _ := strconv.Atoi(fmt.Sprintf("%v", md["port"]))
+	portStr := fmt.Sprintf("%v", md["port"])
+	var port int
+	if portStr != "<nil>" {
+		port, _ = strconv.Atoi(portStr)
+	} else {
+		port = defaultPort
+	}
 	dbname := md["dbname"]
 
-	return username, password, host, port, dbname
+	return username, password, host, port, dbname, nil
 
 }
+
+func defaultDBProviderPort(service VCAPService) int {
+	if isPostgresService(service) {
+		return 5432
+	} else if isMySQLService(service) {
+		return 3306
+	}
+	return 0
+}

src/jetstream/datastore/datastore.go

@@ -96,7 +96,6 @@ func NewDatabaseConnectionParametersFromConfig(dc DatabaseConfig) (DatabaseConfi
 	}
 
 	// Database Config validation - check required values and the SSL Mode
-
 	err := validateRequiredDatabaseParams(dc.Username, dc.Password, dc.Database, dc.Host, dc.Port)
 	if err != nil {
 		return dc, err
@@ -122,8 +121,8 @@ func validateRequiredDatabaseParams(username, password, database, host string, p
 	err = vala.BeginValidation().Validate(
 		vala.IsNotNil(username, "username"),
 		vala.IsNotNil(password, "password"),
-		vala.IsNotNil(database, "database"),
-		vala.IsNotNil(host, "host"),
+		vala.IsNotNil(database, "database name"),
+		vala.IsNotNil(host, "host/hostname"),
 		vala.GreaterThan(port, 0, "port"),
 		vala.Not(vala.GreaterThan(port, 65535, "port")),
 	).Check()

src/jetstream/datastore/datastore_test.go

@@ -145,7 +145,7 @@ func TestDatastore(t *testing.T) {
 			Convey("when database is missing", func() {
 
 				mockDatabaseConfigNoSSL.Database = ""
-				expectedErrorMessage := "parameter validation failed: Parameter was nil: database"
+				expectedErrorMessage := "parameter validation failed: Parameter was nil: database name"
 
 				Convey("an error should be returned", func() {
 					_, err := NewDatabaseConnectionParametersFromConfig(mockDatabaseConfigNoSSL)
@@ -156,7 +156,7 @@ func TestDatastore(t *testing.T) {
 			Convey("when host is missing", func() {
 
 				mockDatabaseConfigNoSSL.Host = ""
-				expectedErrorMessage := "parameter validation failed: Parameter was nil: host"
+				expectedErrorMessage := "parameter validation failed: Parameter was nil: host/hostname"
 
 				Convey("an error should be returned", func() {
 					_, err := NewDatabaseConnectionParametersFromConfig(mockDatabaseConfigNoSSL)
@@ -335,7 +335,7 @@ func TestDatastore(t *testing.T) {
 			Convey("when database is missing", func() {
 
 				mockDatabaseConfigSSL.Database = ""
-				expectedErrorMessage := "parameter validation failed: Parameter was nil: database"
+				expectedErrorMessage := "parameter validation failed: Parameter was nil: database name"
 
 				Convey("an error should be returned", func() {
 					_, err := NewDatabaseConnectionParametersFromConfig(mockDatabaseConfigSSL)
@@ -346,7 +346,7 @@ func TestDatastore(t *testing.T) {
 			Convey("when host is missing", func() {
 
 				mockDatabaseConfigSSL.Host = ""
-				expectedErrorMessage := "parameter validation failed: Parameter was nil: host"
+				expectedErrorMessage := "parameter validation failed: Parameter was nil: host/hostname"
 
 				Convey("an error should be returned", func() {
 					_, err := NewDatabaseConnectionParametersFromConfig(mockDatabaseConfigSSL)