Db2 connection information
In order to connect to Db2 or other database systems like Oracle, PostgreSQL, or MySQL, you typically need the following information:
- hostname: Location (server address) of the Db2 instance. For the new instances it typically is *.databases.appdomain.cloud.
- port: The port to connect to.
- database: The actual database name. For Db2 on Cloud it traditionally is bludb.
- username: The user ID for the connection.
- password: The password for the user ID
Be aware that Db2 on Cloud and Db2 Warehouse on Cloud allow access based on IBM Cloud IAM API keys and access token. Thus, a user name and password are not always needed.
With the update to the new deployment model, SSL/TLS-based access is enforced. By default, all network traffic is encrypted. If you were not using SSL/TLS before, your app needs more changes.
Decode the credentials
The following shows a part of an actual VCAP object. It is a JSON object. To connect to Db2, all interesting information is in the "db2" sub-object. It includes the authentication info (username and password), the database as well as an array of hosts with the hostname and port.
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| Db2 on Cloud credentials (snippet) |
Sample code to extract the connection information and form the URI is available. See this Node.js code as discussed in the tutorial on building a database-driven Slackbot. A Python example with SQLAlchemy is used in the tutorial on serverless eventing and data retrieval. Be aware that in both cases the connection property "Security=SSL;" is added to tell the driver that SSL/TLS is expected.
Conclusions
The new deployment model for Db2 on Cloud, including its free lite plan, change the structure of the credentials object. Knowing what makes up a connection string and how to extract it from the metadata, makes it simple to connect from your app to Db2.
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