正好做Mongodb主从复制尝试使用Spring Boot Data Mongodb Starter插件链接访问Mongodb数据库集群。
遇到的坑：
- spring.data.mongodb.host和spring.data.mongodb.port形式不适合集群配置，会报host无法识别异常
- spring.data.mongodb.uri中经常抛出authentication failed异常
解决办法：
- 对于第一个坑，请使用spring.data.mongodb.uri。如果使用了uri，则其余的host/username/password/db/auth-db这些全部无效。
- 对于第二个坑，请在spring.data.mongodb.uri中指定replicaSet和authsource，另外记得把所有集群节点服务器地址都列全。
如果auth-db和db是同一个，则无需加authsource，如果不同，则加authsource=admin
我没有把authsource指定，所以一直报authentication failed异常。然后只好一点点去发掘问题点，最后查到在com.mongodb.ConnectionString类中的createCredentials中
private MongoCredential createCredentials(final Map<String, List<String>> optionsMap, final String userName,
final char[] password) {
AuthenticationMechanism mechanism = null;
String authSource = (database == null) ? "admin" : database;
String gssapiServiceName = null;
String authMechanismProperties = null;
for (final String key : AUTH_KEYS) {
String value = getLastValue(optionsMap, key);
if (value == null) {
continue;
}
if (key.equals("authmechanism")) {
mechanism = AuthenticationMechanism.fromMechanismName(value);
} else if (key.equals("authsource")) {
authSource = value;
} else if (key.equals("gssapiservicename")) {
gssapiServiceName = value;
} else if (key.equals("authmechanismproperties")) {
authMechanismProperties = value;
}
}
MongoCredential credential = null;
if (mechanism != null) {
switch (mechanism) {
case GSSAPI:
credential = MongoCredential.createGSSAPICredential(userName);
if (gssapiServiceName != null) {
credential = credential.withMechanismProperty("SERVICE_NAME", gssapiServiceName);
}
break;
case PLAIN:
credential = MongoCredential.createPlainCredential(userName, authSource, password);
break;
case MONGODB_CR:
credential = MongoCredential.createMongoCRCredential(userName, authSource, password);
break;
case MONGODB_X509:
credential = MongoCredential.createMongoX509Credential(userName);
break;
case SCRAM_SHA_1:
credential = MongoCredential.createScramSha1Credential(userName, authSource, password);
break;
default:
throw new UnsupportedOperationException(format("The connection string contains an invalid authentication mechanism'. "
+ "'%s' is not a supported authentication mechanism",
mechanism));
}
} else if (userName != null) {
credential = MongoCredential.createCredential(userName, authSource, password);
}
if (credential != null && authMechanismProperties != null) {
for (String part : authMechanismProperties.split(",")) {
String[] mechanismPropertyKeyValue = part.split(":");
if (mechanismPropertyKeyValue.length != 2) {
throw new IllegalArgumentException(format("The connection string contains invalid authentication properties. "
+ "'%s' is not a key value pair", part));
}
String key = mechanismPropertyKeyValue[0].trim().toLowerCase();
String value = mechanismPropertyKeyValue[1].trim();
if (key.equals("canonicalize_host_name")) {
credential = credential.withMechanismProperty(key, Boolean.valueOf(value));
} else {
credential = credential.withMechanismProperty(key, value);
}
}
}
return credential;
}
authSource默认会指向我们目标数据的数据库。然而在身份验证机制中我们通常需要指向admin。（非常想报粗口，代码作者在这里脑袋被men挤了么）。所以需要强制指定authSource中指定。具体指定方式如下：
mongodb://{用户名}:{密码}@{host1}:27017,{host2}:27017,{host3}:27017/{目标数据库}?replicaSet={复制集名称}&write=1&readPreference=primary&authsource={授权数据库}