This tutorial describes Flexmonster Data Server configuration. To install the Data Server, refer to our installation guide.

Table of contents:

• Available configurations
• Setting configurations dynamically
• Examples

Available configurations

Flexmonster Data Server can be configured in the flexmonster-config.json file. It contains the following properties:

• "DataSources" – Array of objects. Allows configuring the data sources. Each object has the following properties:
  • "Type" – String. The type of the data source: "json", "csv", or "database".
  • "DatabaseType" (optional) – String. The type of the database: "mysql", "mssql", "postgresql", or "oracle". Only for "database" data source type.
  • "ConnectionString" (optional) – String. A connection string for the database. Only for "database" data source type.
  • "Indexes" – Object. Contains a list of datasets. Each dataset is represented by a "key": "value" pair, where "key" is a dataset name, and "value" is an object with the following properties:
    • "Path"(optional) – String. The path to the file with data. Only for "json" and "csv" data source types.
    • "Query" (optional) – String. The query to execute (e.g., "SELECT * FROM tablename"). Only for "database" data source type.
    • "Delimiter" (optional) – String. Defines the specific fields separator to split each CSV row. There is no need to define it if the CSV fields are separated by ,. This property is required only if another character separates fields. Default value: ",".
    • "DecimalSeparator" (optional) – String. Defines the specific character used to separate decimal parts of numbers. For example, to import CSV data with commas used to separate decimal parts of numbers (e.g., 3,14), set the "DecimalSeparator" property as ",". Default value: ".".
    • "ThousandSeparator" (optional) – String. Defines the specific character used to separate groups of digits in numbers. For example, to import CSV data with periods used to separate groups of digits in numbers (e.g., 1.000 for one thousand), set the "ThousandSeparator" property as ".". Default value: ",".
• "Security" (optional) – Object. Allows managing the data access security. It contains the following properties:
  • "Authorization" (optional) – Object. Has the following properties:
    • "Enabled" – Boolean. Indicates whether the “Basic Authorization” for Flexmonster Data Server is enabled. When set to true, the authorization is enabled. Default value: false.
  • "CORS" (optional) – Object. Allows configuring the cross-origin resource sharing for Flexmonster Data Server. It contains the following properties:
    • "AllowOrigin" (optional) – String. The origin from which the server accepts the requests. If "AllowOrigin" is set to "*", requests from all origins are accepted.
      Note that if authorization is enabled ("Enabled": true), "*" cannot be set as the origin. In this case, specific origins must be defined. Several origins can be defined as follows:

      "AllowOrigin": "http://localhost, https://example.com"

      Default value: "*".
  • "HSTS" (optional) — Object. Allows configuring the Strict-Transport-Security (HSTS) response header. Contains the following properties:
    • "MaxAge" — Number. Defines how long the browser remembers that the site should be accessed only via HTTPS. The "MaxAge" property is set in seconds.
    • "IncludeSubDomains" (optional) — Boolean. Defines whether the Strict-Transport-Security header applies to the site’s subdomains (true) or not (false). Default value: false.
    • "Preload" (optional) — Boolean. Defines whether the site is in the HSTS preload list (true) or not (false). For details refer to the MDN documentation about HSTS. Default value: false.
  • "Headers" (optional) — Object. Allows adding response headers. This object consists of "key": "value" pairs, where "key" is a header name, and "value" is its value.
    We recommend adding response headers carefully and only if they are required for the project. Specifying an existing header with the wrong value can lead to runtime errors.
    Here is an example of how response headers can be specified:

    "Headers": {
        "Content-Security-Policy": "default-src 'self'",
        "X-Content-Type-Options": "nosniff",
        "X-Frame-Options": "SAMEORIGIN",
        "X-XSS-Protection": "1; mode=block"
    }
    

• "DataStorageOptions" (optional) – Object. Allows configuring options for data storage. It has the following properties:
  • "DataRefreshTime" (optional) – Number. Defines how often the data is reloaded from a file or a database. The refresh time is set in minutes. If the "DataRefreshTime" is not specified, the data will not be reloaded.
  • "CacheSizeLimit" (optional) – Number. The maximum number of cached server responses for every index defined in the "DataSources" property. When set to 0, the Data Server does not cache the responses. Default value: 100.
    
• "Port" (optional) – String. The number of the port Flexmonster Data Server runs on. Also, it can be set by running this command in the console:

  on Windows

  flexmonster-data-server.exe -p 7777

  on macOS and Ubuntu/Linux

  ./flexmonster-data-server -p 7777

  Default value: "9500".
• "HTTPS" (optional) – Object. Allows configuring the HTTPS protocol. It contains the following properties:
  • "Enable" (optional) – Boolean. Indicates whether the HTTPS protocol is enabled (true) or not (false). Default value: false.
  • "Certificate" (optional) – Path-Password Object|Subject-Store Object. Allows adding a certificate. By default, if the certificate is not specified, the generated development certificate will be used. The certificate can be added with either Path-Password Object or Subject-Store Object. Each of them has different properties.
    The Path-Password Object has the following properties:
    • "Path" – String. The URL to the certificate file.
    • "Password" – String. The password to access the certificate.
    The Subject-Store Object has the following properties:
    • "Subject" – String. The certificate subject name.
    • "Store" – String. The store from which the certificate is loaded.
    • "Location" (optional) – String. The location of the store from which to load the certificate. It can be either "CurrentUser" or "LocalMachine". Default value: "CurrentUser".
    • "AllowInvalid" (optional) – Boolean. Indicates whether to allow using invalid certificates (e.g., self-signed certificates). When set to true, invalid certificates are allowed to use. Default value: false.
  • "Protocols" (optional) – String. Establishes the HTTP protocols enabled on a connection endpoint or for the server. It can be one of the following values: "Http1", "Http2", and "Http1AndHttp2". Default value: "Http1AndHttp2".

Setting configurations dynamically

To store the connection strings and other configurations more securely, set them dynamically as command-line arguments or environment variables.

Follow a short guide to set dynamic configurations:

Step 1. Assign the parameter to the needed configuration as follows:

"DataSources": [{ 
    "Type": "database",
    "DatabaseType": "postgresql",
    "ConnectionString": "${param}",
    "Indexes": {
        "index_database": {
            "Query": "SELECT * FROM ${param2}"
        }
    }
}],

param and param2 are the names of your parameters.

Step 2. Using the parameter’s name (e.g., param), pass your value to the Data Server:

flexmonster-data-server.exe param=connectionString param2=tableName

./flexmonster-data-server param=connectionString param2=tableName

Examples

Here is an example of configured flexmonster-config.json:

{
   "DataSources": [
     {
       "Type": "json",
       "Indexes": {
         "index_json": {
           "Path": "./data/data.json"
         }
       }
     },
     {
       "Type": "database",
       "DatabaseType": "mysql",
       "ConnectionString":
 "Server=localhost;Port=3333;Uid=root;Pwd=pwd;Database=TestDB",
       "Indexes": {
         "index_database": {
           "Query": "SELECT * FROM TestTable;"
         }
       }
     }
   ],
   "Security": {
     "Authorization": {
       "Enabled": false
     },
     "CORS": {
       "AllowOrigin": "*"
     }, 
     "HSTS": {
       "MaxAge": 31536000,
       "IncludeSubDomains": true
     },
     "Headers": {
       "Content-Security-Policy": "default-src 'self'",
       "X-Content-Type-Options": "nosniff",
       "X-Frame-Options": "SAMEORIGIN",
       "X-XSS-Protection": "1; mode=block"
     } 
   },
   "DataStorageOptions": {
     "DataRefreshTime": 60,
     "CacheSizeLimit": 150
   },
   "Port": "9500",
   "HTTPS": {
     "Enabled": true,
     "Certificate": {
       "Subject": "localhost",
       "Store": "My"
     },
     "Protocols": "Http2"
   }
}

What’s next?

You may be interested in the following articles:

• Data sources guide
• Security and authorization guide