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Finish connections and passwords

The importer creates one Hop connection for every Talend repository connection, under the same name, and one for every other database the components use, in metadata/rdbms/. Components that use the same database, with the same user and password, share one connection.

A connection's settings are variables, not values. A setting the Talend job took from a context variable keeps it: context.dbHost becomes ${dbHost}. A setting the job had as a literal becomes a variable named after the connection: ${<connection>_HOST}, _PORT, _DATABASE, _USER, _SCHEMA and _PASSWORD. The import writes the value the Talend job had into every environment file under environments/, so the connections work as soon as you run with one of those environments, and you change a host or a user per environment without touching the project.

What the import cannot carry is a password Talend encrypted: Talend encrypts passwords in an export with a key that is not in it.

1. See what needs a value​

In the migration report:

  • Environments lists the variables the connections read, and the environment files that hold them.
  • Passwords lists every connection and context variable whose password Talend encrypted. Its variable is empty in every environment.
  • Connections lists the repository connections, their database type, and encrypted by Talend where you have to add the password.

Open a connection in Hop GUI (Metadata → Relational Database Connection) to see the variables it reads. For a connection named QBC: host ${QBC_HOST}, user ${QBC_USER}, password ${QBC_PASSWORD}.

2. Set the values per environment​

Keep the values out of the project. Don't type a password into the connection either: the connection file would then hold it, and Hop's Encrypted prefix in that file is obfuscation, not encryption. For each environment you run with:

  1. Create a config file outside the project folder, for example qbc-test.json:

    {
      "variables" : [
        { "name" : "QBC_HOST", "value" : "sqlserver-test.example.com" },
        { "name" : "QBC_PASSWORD", "value" : "…" }
      ]
    }

  2. Add it to the environment after the file the import wrote, so that its values win: in Hop GUI under the environment's configuration files, or with hop-conf -em -e <environment> -ep <project> -eg <imported file>,<your file>.

Set only what differs: a variable your file does not mention keeps the imported value. A password can also come from the environment of the process that runs Hop.

3. Check the database type and driver​

The connection's database type follows the Talend component. Two to know:

  • SQL Server connections are MS SQL Server (Native), with Microsoft's JDBC driver, which Hop ships and Talend's SQL Server components use by default. Encryption is off, as Talend connects; turn it on in the connection's options if your server requires it. A Talend connection that used the jTDS driver with connection properties of its own gets a review note: Microsoft's driver names them differently.
  • Generic JDBC (tJDBC*) connections are a Hop generic connection with the component's JDBC URL and driver class. Put the driver jar in <hop>/lib/jdbc on every machine that runs the pipelines.

4. Test​

Select the environment you are going to run with, then use Test in the connection dialog. The test reads the variables from that environment: without one, they are unset.