SQL Server

Connect & Ingest data from / to a SQL Server database

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:[e-mail]: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).

• trusted_connection -> true or false - whether to connects to SQL Server with a trusted connection using integrated security (also will use the -T flag when using bulk loading with bcp)

• trust_server_certificate -> true or false - whether the 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.

• bcp_auth_string -> A way to override the way bcp authenticates. Accepts an array of strings, for example ['U', 'username', '-T', '-G'] will append flags -U username -T -G to the bcp command.

• bcp_extra_args (v1.2.23) -> A way to add additional args to the bcp command. Accepts an array of strings, for example ['b', '5000'] will append flags -b 5000 to the bcp command.

• bcp_path (v1.3.0)-> The path to the bcp binary. This is useful if you need to specify a custom path for bcp.

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.

  authenticator=krb5
  krb5_config_file=/etc/krb5.conf
  krb5_cred_cache_file=~/user_cached_creds 
• Raw credentials - Specity krb5.confg, Username, Password and Realm.

  authenticator=krb5
  krb5_realm=comani.com
  krb5_config_file=/etc/krb5.conf

---

Using sling conns

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:[e-mail]:1433?database=mydatabase"
$ sling conns set MSSQL url="sqlserver://myuser:[e-mail]:1433/my_instance?database=master&encrypt=true&TrustServerCertificate=true"

Environment Variable

export MSSQL='sqlserver://myuser:[e-mail]:1433?database=mydatabase'
export MSSQL='sqlserver://myuser:[e-mail]:1433/my_instance?database=master&encrypt=true&TrustServerCertificate=true'

Sling Env File YAML

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

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

  MSSQL_URL:
    url: "sqlserver://myuser:[e-mail]:1433/mydatabase"

  MSSQL_KERBEROS:
    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 [e-mail], on discord or open a Github Issue here.