[FAB-3094] CouchDB Errors if system databases missing

CouchDB log fills with errors if its system databases are not created.
The system databases should be created upon peer startup,
if they do not yet exist.

This change makes a simple check on creating the state database to
check if the system database exist as well.  If they are missing, then
the system databases are created.

Change-Id: I6dacb8ceefcda8fd0f14a0ef55da921b9160343d
Signed-off-by: Chris Elder <chris.elder@us.ibm.com>

core/ledger/util/couchdb/couchdb.go

@@ -321,8 +321,11 @@ func (dbclient *CouchDatabase) GetDatabaseInfo() (*DBInfo, *DBReturn, error) {
 
 }
 
-//VerifyConnection method provides function to verify the connection information
-func (couchInstance *CouchInstance) VerifyConnection() (*ConnectionInfo, *DBReturn, error) {
+//VerifyCouchConfig method provides function to verify the connection information
+func (couchInstance *CouchInstance) VerifyCouchConfig() (*ConnectionInfo, *DBReturn, error) {
+
+	logger.Debugf("Entering VerifyCouchConfig()")
+	defer logger.Debugf("Exiting VerifyCouchConfig()")
 
 	connectURL, err := url.Parse(couchInstance.conf.URL)
 	if err != nil {
@@ -334,16 +337,18 @@ func (couchInstance *CouchInstance) VerifyConnection() (*ConnectionInfo, *DBRetu
 	//get the number of retries for startup
 	maxRetriesOnStartup := couchInstance.conf.MaxRetriesOnStartup
 
-	resp, couchDBReturn, err := couchInstance.handleRequest(http.MethodGet, connectURL.String(), nil, "", "", maxRetriesOnStartup)
+	resp, couchDBReturn, err := couchInstance.handleRequest(http.MethodGet, connectURL.String(), nil,
+		couchInstance.conf.Username, couchInstance.conf.Password, maxRetriesOnStartup)
+
 	if err != nil {
-		return nil, couchDBReturn, err
+		return nil, couchDBReturn, fmt.Errorf("Unable to connect to CouchDB, check the hostname and port: %s", err.Error())
 	}
 	defer resp.Body.Close()
 
 	dbResponse := &ConnectionInfo{}
 	errJSON := json.NewDecoder(resp.Body).Decode(&dbResponse)
 	if errJSON != nil {
-		return nil, nil, errJSON
+		return nil, nil, fmt.Errorf("Unable to connect to CouchDB, check the hostname and port: %s", errJSON.Error())
 	}
 
 	// trace the database info response
@@ -354,6 +359,16 @@ func (couchInstance *CouchInstance) VerifyConnection() (*ConnectionInfo, *DBRetu
 		}
 	}
 
+	//check to see if the system databases exist
+	//Verifying the existence of the system database accomplishes two steps
+	//1.  Ensures the system databases are created
+	//2.  Verifies the username password provided in the CouchDB config are valid for system admin
+	err = CreateSystemDatabasesIfNotExist(*couchInstance)
+	if err != nil {
+		logger.Errorf("Unable to connect to CouchDB,  error: %s   Check the admin username and password.\n", err.Error())
+		return nil, nil, fmt.Errorf("Unable to connect to CouchDB,  error: %s   Check the admin username and password.\n", err.Error())
+	}
+
 	return dbResponse, couchDBReturn, nil
 
 }

core/ledger/util/couchdb/couchdbutil.go

@@ -41,9 +41,9 @@ func CreateCouchInstance(couchDBConnectURL, id, pw string, maxRetries,
 	//Create the CouchDB instance
 	couchInstance := &CouchInstance{conf: *couchConf}
 
-	connectInfo, retVal, verifyErr := couchInstance.VerifyConnection()
+	connectInfo, retVal, verifyErr := couchInstance.VerifyCouchConfig()
 	if verifyErr != nil {
-		return nil, fmt.Errorf("Unable to connect to CouchDB, check the hostname and port: %s", verifyErr.Error())
+		return nil, verifyErr
 	}
 
 	//return an error if the http return value is not 200
@@ -96,6 +96,37 @@ func CreateCouchDatabase(couchInstance CouchInstance, dbName string) (*CouchData
 	return &couchDBDatabase, nil
 }
 
+//CreateSystemDatabasesIfNotExist - creates the system databases if they do not exist
+func CreateSystemDatabasesIfNotExist(couchInstance CouchInstance) error {
+
+	dbName := "_users"
+	systemCouchDBDatabase := CouchDatabase{CouchInstance: couchInstance, DBName: dbName}
+	_, err := systemCouchDBDatabase.CreateDatabaseIfNotExist()
+	if err != nil {
+		logger.Errorf("Error during CouchDB CreateDatabaseIfNotExist() for system dbName: %s  error: %s\n", dbName, err.Error())
+		return err
+	}
+
+	dbName = "_replicator"
+	systemCouchDBDatabase = CouchDatabase{CouchInstance: couchInstance, DBName: dbName}
+	_, err = systemCouchDBDatabase.CreateDatabaseIfNotExist()
+	if err != nil {
+		logger.Errorf("Error during CouchDB CreateDatabaseIfNotExist() for system dbName: %s  error: %s\n", dbName, err.Error())
+		return err
+	}
+
+	dbName = "_global_changes"
+	systemCouchDBDatabase = CouchDatabase{CouchInstance: couchInstance, DBName: dbName}
+	_, err = systemCouchDBDatabase.CreateDatabaseIfNotExist()
+	if err != nil {
+		logger.Errorf("Error during CouchDB CreateDatabaseIfNotExist() for system dbName: %s  error: %s\n", dbName, err.Error())
+		return err
+	}
+
+	return nil
+
+}
+
 //mapAndValidateDatabaseName checks to see if the database name contains illegal characters
 //CouchDB Rules: Only lowercase characters (a-z), digits (0-9), and any of the characters
 //_, $, (, ), +, -, and / are allowed. Must begin with a letter.

core/ledger/util/couchdb/couchdbutil_test.go

@@ -26,7 +26,7 @@ import (
 
 //Unit test of couch db util functionality
 func TestCreateCouchDBConnectionAndDB(t *testing.T) {
-	if ledgerconfig.IsCouchDBEnabled() == true {
+	if ledgerconfig.IsCouchDBEnabled() {
 
 		database := "testcreatecouchdbconnectionanddb"
 		cleanup(database)
@@ -41,6 +41,46 @@ func TestCreateCouchDBConnectionAndDB(t *testing.T) {
 
 }
 
+//Unit test of couch db util functionality
+func TestCreateCouchDBSystemDBs(t *testing.T) {
+	if ledgerconfig.IsCouchDBEnabled() {
+
+		database := "testcreatecouchdbsystemdb"
+		cleanup(database)
+		defer cleanup(database)
+
+		//create a new connection
+		couchInstance, err := CreateCouchInstance(connectURL, "", "", maxRetries,
+			maxRetriesOnStartup, requestTimeout)
+		testutil.AssertNoError(t, err, fmt.Sprintf("Error when trying to CreateCouchInstance"))
+
+		err = CreateSystemDatabasesIfNotExist(*couchInstance)
+		testutil.AssertNoError(t, err, fmt.Sprintf("Error when trying to create system databases"))
+
+		db := CouchDatabase{CouchInstance: *couchInstance, DBName: "_users"}
+
+		//Retrieve the info for the new database and make sure the name matches
+		dbResp, _, errdb := db.GetDatabaseInfo()
+		testutil.AssertNoError(t, errdb, fmt.Sprintf("Error when trying to retrieve _users database information"))
+		testutil.AssertEquals(t, dbResp.DbName, "_users")
+
+		db = CouchDatabase{CouchInstance: *couchInstance, DBName: "_replicator"}
+
+		//Retrieve the info for the new database and make sure the name matches
+		dbResp, _, errdb = db.GetDatabaseInfo()
+		testutil.AssertNoError(t, errdb, fmt.Sprintf("Error when trying to retrieve _replicator database information"))
+		testutil.AssertEquals(t, dbResp.DbName, "_replicator")
+
+		db = CouchDatabase{CouchInstance: *couchInstance, DBName: "_global_changes"}
+
+		//Retrieve the info for the new database and make sure the name matches
+		dbResp, _, errdb = db.GetDatabaseInfo()
+		testutil.AssertNoError(t, errdb, fmt.Sprintf("Error when trying to retrieve _global_changes database information"))
+		testutil.AssertEquals(t, dbResp.DbName, "_global_changes")
+
+	}
+
+}
 func TestDatabaseMapping(t *testing.T) {
 
 	//create a new instance and database object using a database name mixed case