Forum Discussion

Kash10's avatar
Kash10
Regular Visitor
10 months ago
Solved

Unable to connect MS Fabric and Azure database for Postgres using copy activity

Hi All, I’m having issues establishing connectivity between Microsoft Fabric and Azure Database for PostgreSQL using the Copy Activity. When I try connecting without an on-prem data gateway, Fabric...
  • Kash10's avatar
    Kash10
    9 months ago

    Hi All,

    Thanks for your support , the issue has now been resolved. With the same tech stack, the on-premises data gateway works as expected.

    Below is the additional action required:

    Microsoft Fabric currently does not support mutual TLS (mTLS) when connecting to PostgreSQL. It only supports standard TLS with username/password authentication and cannot present the client certificate and key required by our mTLS-enabled PgBouncer endpoint. Due to this limitation, Fabric fails during the handshake phase, resulting in the error observed.

    To enable Fabric connectivity while preserving our existing security posture, we will proceed with Alternative 1 from our internal analysis:

    ✅Planned Approach
    We will relax mTLS enforcement only for Fabric by setting up a dedicated PgBouncer listener/pool that:

    • does not require client certificates,

    • is accessible from Fabric’s data gateway public IP range, and IP address of on prem data gateway.

    • retains full mTLS enforcement for all other traffic.This approach allows us to maintain strong security controls while ensuring Fabric can connect successfully.

Zanqueta's avatar
Zanqueta
Icon for Super User rankSuper User
10 months ago

hi Kash10,

 

This is a common challenge when connecting Microsoft Fabric Data Pipelines to Azure Database for PostgreSQL, because Fabric currently does not expose fixed outbound IPs for whitelisting. Let me break down why this happens and what you can do:
 

Possible Solutions / Workarounds

Option 1: Use VNet Integration with Managed Private Endpoints

Option 2: Use On-Premises Data Gateway (Correct Configuration)

 Ensure the gateway is installed on a machine that can reach Azure PostgreSQL.

  • In the Copy Activity:
    • Select Gateway connection explicitly.
    • Verify that the gateway is online and mapped to the PostgreSQL connector.
  • Whitelist the public IP of the gateway machine in the PostgreSQL firewall.
  • Check that SSL is enabled in the connection string (PostgreSQL requires SSL by default).

 

If this helps, please give a 👍 and mark as solution. It saves others from chasing dynamic IP ghosts! 🌀
 

 

Kash10's avatar
Kash10
Regular Visitor
10 months ago

Hi Zanqueta,

 

Regarding option 2, I have already covered all the steps listed, however as soon as I select the on prem data gateway from the drop down list, I get the error "3 arguments were passed to a function that expects 2"

  • Zanqueta's avatar
    Zanqueta
    Icon for Super User rankSuper User
    10 months ago

    Thanks for you feedback Kash10, 

     

    In your Power BI Desktop it was working? Are you using parameters or get the string directly?
     
    This typically occurs due to the way parameters are passed when selecting the gateway.
     
    Please, look at this when creating the connection in Fabric:
     
    • Only specify:
      • Server: servername.postgres.database.azure.com
      • Database
      • Authentication: username@servername and password
    • Enable SSL, as this is mandatory for Azure PostgreSQL.

     

    If this response was helpful in any way, I’d gladly accept a 👍much like the joy of seeing a DAX measure work first time without needing another FILTER.

    Please mark it as the correct solution. It helps other community members find their way faster (and saves them from another endless loop 🌀.

     

     

    • Kash10's avatar
      Kash10
      Regular Visitor
      10 months ago

      Hi Zanqueta,

       

      I am trying to connect through data factory, haven't tried through Power BI Desktop as my requirement is more from a data engineering perspective. I have used the connection strings directly as you have mentioned, still it's not connecting.

      • v-sgandrathi's avatar
        v-sgandrathi
        Icon for Community Support rankCommunity Support
        10 months ago

        Hi Kash10,

         

        It appears that the main issue is Fabric Data Factory’s inability to connect to Azure PostgreSQL because the connection is routed through the public network, and Fabric doesn’t provide fixed outbound IPs. As a result, whitelisting the gateway machine’s IP isn’t a reliable solution. The recommended approach is to enable Managed VNet in your Fabric workspace and set up a Managed Private Endpoint to your Azure PostgreSQL instance (which should have Private Link enabled). This configuration allows for private network communication, avoiding IP-based firewall issues. If you choose to use the on-premises data gateway, make sure it’s updated, properly mapped to the PostgreSQL connector, and that SSL and the correct credentials (username@servername) are used. 

         

        Thank you.