SQL Server

Connect & Ingest data from / to a SQL Server database

Sling CLI Setup

The following credentials keys are accepted:

  • host (required) -> The hostname / ip of the instance

  • user (required) -> The username to access the instance

  • database (required) -> The database name of the instance

  • instance (optional) -> The SQL Server instance to use

  • schema (optional) -> The default schema to use

  • password (optional) -> The password to access the instance

  • port (optional) -> The port of the instance. Default is 1433.

  • authenticator (optional) -> Can be used to specify use of a registered authentication provider. (e.g. ntlm, winsspi (on windows) or krb5 (on linux))

  • ssh_tunnel (optional) -> The URL of the SSH server you would like to use as a tunnel (example ssh://user:password@db.host:22)

  • ssh_private_key (optional) -> The private key to use to access a SSH server (raw string or path to file).

  • ssh_passphrase (optional) -> The passphrase to use to access a SSH server.

Additional Parameters

Sling uses the go-mssqldb library and thus will accept any paremters listed here. Some parameters that may be of interest:

  • encrypt -> strict, disable, false or true - whether data between client and server is encrypted.

  • log -> logging level (accepts 1, 2, 4, 8, 16, 32).

  • trust_server_certificate -> true or false - whetherthe server certificate is checked

  • certificate -> The file that contains the public key certificate of the CA that signed the SQL Server certificate. The specified certificate overrides the go platform specific CA certificates.

  • hostname_in_certificate -> Specifies the Common Name (CN) in the server certificate. Default value is the server host.

  • server_spn (v1.2.3) -> The kerberos SPN (Service Principal Name) for the server. Default is MSSQLSvc/host:port.

Kerberos Parameters

Since v1.2.3

  • authenticator - set this to krb5 to enable kerberos authentication. If this is not present, the default provider would be ntlm for unix and winsspi for windows.

  • krb5_config_file (optional) - path to kerberos configuration file. Defaults to /etc/krb5.conf. Can also be set using KRB5_CONFIG environment variable.

  • krb5_realm (required with keytab and raw credentials) - Domain name for kerberos authentication. Omit this parameter if the realm is part of the user name like username@REALM.

  • krb5_keytab_file - path to Keytab file. Can also be set using environment variable KRB5_KTNAME. If no parameter or environment variable is set, the DefaultClientKeytabName value from the krb5 config file is used.

  • krb5_cred_cache_file - path to Credential cache. Can also be set using environment variable KRBCCNAME.

  • krb5_dns_lookup_kdc - Optional parameter in all contexts. Set to lookup KDCs in DNS. Boolean. Default is true.

  • krb5_udp_preference_limit - Optional parameter in all contexts. 1 means to always use tcp. MIT krb5 has a default value of 1465, and it prevents user setting more than 32700. Integer. Default is 1.

Sling supports authentication via 3 methods. See here for more details.

  • Keytabs - Specify the username, keytab file, the krb5.conf file, and realm.

    authenticator: krb5
    krb5_realm: domain.com
    krb5_config_file: /etc/krb5.conf
    krb5_keytab_file: ~/user.keytab
  • Credential Cache - Specify the krb5.conf file path and credential cache file path.

  • Raw credentials - Specity krb5.confg, Username, Password and Realm.


Here are examples of setting a connection named MSSQL. We must provide the type=sqlserver property:

$ sling conns set MSSQL type=sqlserver host=<host> user=<user> database=<database> password=<password> port=<port>

# Or use url
$ sling conns set MSSQL url="sqlserver://myuser:mypass@host.ip:1433?database=mydatabase"
$ sling conns set MSSQL url="sqlserver://myuser:mypass@host.ip:1433/my_instance?database=master&encrypt=true&TrustServerCertificate=true"

Environment Variable

export MSSQL='sqlserver://myuser:mypass@host.ip:1433?database=mydatabase'
export MSSQL='sqlserver://myuser:mypass@host.ip:1433/my_instance?database=master&encrypt=true&TrustServerCertificate=true'

Sling Env File YAML

See here to learn more about the sling env.yaml file.

    type: sqlserver
    host: <host>
    user: <user>
    port: <port>
    instance: <instance>
    database: <database>
    schema: <schema>
    password: <password>
    encrypt: 'true'
    trust_server_certificate: 'true'

    url: "sqlserver://myuser:mypass@host.ip:1433/mydatabase"

    type: sqlserver
    host: <host>
    user: <user>
    port: <port>
    instance: <instance>
    database: <database>
    schema: <schema>
    password: <password>
    authenticator: 'krb5'
    krb5_config_file: /etc/krb5.conf
    krb5_realm: domain.com
    krb5_keytab_file: ~/MyUserName.keytab
    krb5_credcache_file: ~/MyUserNameCachedCreds

If you are facing issues connecting, please reach out to us at support@slingdata.io, on discord or open a Github Issue here.

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