官網配置

前言

由於以前使用mongo都是簡單的本地裸奔，根本沒有設定過使用者密碼，昨天收到運維同事反饋說伺服器被挖礦木馬攻擊了，嚇得趕緊在docker裡面開啟認證，但是設定完後問題來了，開發同事又說不能用配置檔案如下

spring:
  data:
    mongodb:
      host: 127.0.0.1
      port: 27017
      username: sunny
      password: 123456
      database: admin

看起來很ok但是在啟動boot的時候在會連線兩次（別問我為什麼是兩次，boot原始碼還沒有看多少），第一次是失敗了，但是第二次成功了，但是讀取資料時候又用的是mongoTemplate

配置檔案（yml）

spring:
  data:
    mongodb:
      uri: mongodb://localhost:27017/file

對應的java程式碼是

@ConfigurationProperties(prefix = "spring.data.mongodb")
public class MongoProperties {
    public static final String DEFAULT_URI = "mongodb://localhost/test"
 
;
    // 預設uri=
    public String determineUri() {
        return (this.uri != null ? this.uri : DEFAULT_URI);
    }
    ....
    // 關鍵程式碼 idea ctrl+g 169 就可以看到
    public String getMongoClientDatabase() {
        if (this.database != null) {
            return this.database;
        }
        return new
 
 MongoClientURI(determineUri()).getDatabase();
    }
}
// 讀取yml檔案字首為（spring.data.mongodb）

由原始碼可以看出這裡如果uri=null則使用DEFAULT_URI，然後進入MongoClientURI 類

public class MongoClientURI {
    private final ConnectionString proxied;
    private final MongoClientOptions.Builder builder;

    /**
     * Creates a MongoURI from the given string.
     * 從給定的字串建立一個MongoURI
     * @param uri the URI
     */
    public MongoClientURI(final String uri) {
        this(uri, new MongoClientOptions.Builder());
    }
     /**
     * Mongo database URI. Cannot be set with host, port and credentials.
     */
    public MongoClientURI(final String uri, final MongoClientOptions.Builder builder) {
        this.builder = notNull("builder", builder);
        proxied = new ConnectionString(uri);
    }
}

到這裡了就先看new MongoClientOptions.Builder() 方法

@Immutable
public class MongoClientOptions {
        /**
         * Creates a Builder for MongoClientOptions, getting the appropriate system properties            *for initialization.
         *  這裡MongoClientOptions建立一個構建器，並且設定一些系統屬性
         */
        public Builder() {
    /*設定心跳頻率，在叢集中*/        heartbeatFrequency(Integer.parseInt(System.getProperty("com.mongodb.updaterIntervalMS", "10000")));
    /*最小心跳頻率*/ minHeartbeatFrequency(Integer.parseInt(System.getProperty("com.mongodb.updaterIntervalNoMasterMS", "500")));
    /*設定用於群集心跳的連線的連線超時*/        heartbeatConnectTimeout(Integer.parseInt(System.getProperty("com.mongodb.updaterConnectTimeoutMS", "20000")));
    /*socket 連結超時*/        heartbeatSocketTimeout(Integer.parseInt(System.getProperty("com.mongodb.updaterSocketTimeoutMS", "20000")));
    /*可接受的延遲差 15秒*/        localThreshold(Integer.parseInt(System.getProperty("com.mongodb.slaveAcceptableLatencyMS", "15")));
        }
}

System.getProperty（xxxx）可以在jvm裡面設定或者直接在boot啟動方法裡面設定。

看到這裡後發現使用了一個proxied（代理）繼續往下看

  public class ConnectionString {  
  /**
     * Creates a ConnectionString from the given string.
     * 
     * @param connectionString     the connection string
     * @since 3.0
     */
    public ConnectionString(final String connectionString) {
        this.connectionString = connectionString;
        //這裡可以看出支援兩種協議:mongodb://和mongodb+srv://
        boolean isMongoDBProtocol = connectionString.startsWith(MONGODB_PREFIX);
        boolean isSRVProtocol = connectionString.startsWith(MONGODB_SRV_PREFIX);
        if (!isMongoDBProtocol && !isSRVProtocol) {
            throw new IllegalArgumentException(format("The connection string is invalid. "
                    + "Connection strings must start with either '%s' or '%s", MONGODB_PREFIX, MONGODB_SRV_PREFIX));
        }
        // 擷取協議頭，eg：sunny:[email protected]:27007/file?connectTimeoutMS=400000
        String unprocessedConnectionString;
        if (isMongoDBProtocol) {
            unprocessedConnectionString = connectionString.substring(MONGODB_PREFIX.length());
        } else {
            unprocessedConnectionString = connectionString.substring(MONGODB_SRV_PREFIX.length());
        }

        // 分割出使用者和主機資訊 eg：sunny:[email protected]:27007
        String userAndHostInformation;
        int idx = unprocessedConnectionString.lastIndexOf("/");
        if (idx == -1) {
            if (unprocessedConnectionString.contains("?")) {
                throw new IllegalArgumentException("The connection string contains options without trailing slash");
            }
            userAndHostInformation = unprocessedConnectionString;
            unprocessedConnectionString = "";
        } else {
            //userAndHostInformation=sunny:[email protected]:27007
            userAndHostInformation = unprocessedConnectionString.substring(0, idx);
             // unprocessedConnectionString=file?connectTimeoutMS=400000
            unprocessedConnectionString = unprocessedConnectionString.substring(idx + 1);
        }

        // Split the user and host information
        String userInfo;
        String hostIdentifier;
        String userName = null;
        char[] password = null;
        idx = userAndHostInformation.lastIndexOf("@");
        if (idx > 0) {
            // userInfo=sunny:123456
            userInfo = userAndHostInformation.substring(0, idx);
            //  hostIdentifier=127.0.0.1:27007
            hostIdentifier = userAndHostInformation.substring(idx + 1);
            // 判斷userInfo是否包含@和：出現次數大於1
            int colonCount = countOccurrences(userInfo, ":");
            if (userInfo.contains("@") || colonCount > 1) {
                throw new IllegalArgumentException("The connection string contains invalid user information. "
                        + "If the username or password contains a colon (:) or an at-sign (@) then it must be urlencoded");
            }
            if (colonCount == 0) {
                userName = urldecode(userInfo);
            } else {
                // idx=5
                idx = userInfo.indexOf(":");
                // userName=sunny
                userName = urldecode(userInfo.substring(0, idx));
                //passpword=123456
                password = urldecode(userInfo.substring(idx + 1), true).toCharArray();
            }
        } else {
            hostIdentifier = userAndHostInformation;
        }

        // 驗證host
        List<String> unresolvedHosts = unmodifiableList(parseHosts(asList(hostIdentifier.split(",")), isSRVProtocol));
        this.hosts = isSRVProtocol ? resolveHostFromSrvRecords(unresolvedHosts.get(0)) : unresolvedHosts;

        // 解析引數
        String nsPart;
        idx = unprocessedConnectionString.indexOf("?");
        if (idx == -1) {
            nsPart = unprocessedConnectionString;
            unprocessedConnectionString = "";
        } else {
            // nsPart=file 獲取資料庫名稱
            nsPart = unprocessedConnectionString.substring(0, idx);
            // unprocessedConnectionString=connectTimeoutMS=400000
            unprocessedConnectionString = unprocessedConnectionString.substring(idx + 1);
        }
        if (nsPart.length() > 0) {
            nsPart = urldecode(nsPart);
            idx = nsPart.indexOf(".");
            // 是否指定集合
            if (idx < 0) {
                database = nsPart;
                collection = null;
            } else {
                database = nsPart.substring(0, idx);
                collection = nsPart.substring(idx + 1);
            }
        } else {
            database = null;
            collection = null;
        }
        /*資料庫健康連結 mongodb+srv 協議才使用*/
        String txtRecordsQueryParameters = isSRVProtocol ? resolveAdditionalQueryParametersFromTxtRecords(unresolvedHosts.get(0)) : "";
        /*連結引數  connectTimeoutMS=400000*/
        String connectionStringQueryParamenters = unprocessedConnectionString;

        Map<String, List<String>> connectionStringOptionsMap = parseOptions(connectionStringQueryParamenters);
        Map<String, List<String>> txtRecordsOptionsMap = parseOptions(txtRecordsQueryParameters);
        //判斷是否設定 authsource、replicaset
        if (!ALLOWED_OPTIONS_IN_TXT_RECORD.containsAll(txtRecordsOptionsMap.keySet())) {
            throw new MongoConfigurationException(format("A TXT record is only permitted to contain the keys %s, but the TXT record for "
            + "'%s' contains the keys %s", ALLOWED_OPTIONS_IN_TXT_RECORD, unresolvedHosts.get(0), txtRecordsOptionsMap.keySet()));
        }
        Map<String, List<String>> combinedOptionsMaps = combineOptionsMaps(txtRecordsOptionsMap, connectionStringOptionsMap);
        if (isSRVProtocol && !combinedOptionsMaps.containsKey("ssl")) {
            combinedOptionsMaps.put("ssl", singletonList("true"));
        }
        translateOptions(combinedOptionsMaps);
        credential = createCredentials(combinedOptionsMaps, userName, password);
        warnOnUnsupportedOptions(combinedOptionsMaps);
    }
  }

完結

mongo這塊程式碼是臨時看的，可能沒有太認真，如果有誤請指出，還有就是mongodb+srv 協議沒有使用過，有使用經驗的歡迎留言交流，謝謝