Allow overriding all postgres connection attributes

[jtamagnan]

What changed?

User provided connection attributes take precedent over ones set automatically the code.

Why?

This fixes #8436 by allowing users to set sslmode through connectAttributes.

How did you test it?

• built
• run locally and tested manually
• covered by existing tests
• added new unit test(s)
• added new functional test(s)

Potential risks

Users may override values that they didn't intend to, where the server would fail to start up before.

[CLAassistant]

All committers have signed the CLA.

[bergundy]

Thanks for the contribution. Instead of what you've done here, let's change the if in line 96 to first check parameters.Get(sslMode) and avoid setting the mode if a user provided a specific mode.

[jtamagnan]

Thanks for the review! Really excited to get this PR in.

Thanks for the contribution. Instead of what you've done here, let's change the if in line 96 to first check parameters.Get(sslMode) and avoid setting the mode if a user provided a specific mode.

I'm sorry. I'm a bit confused by this. On line 96 parameters.Get(sslMode) should always be "" since we haven't set it yet. Do you mean checking cfg.ConnectAttributes[sslMode]?

[bergundy]

Thanks for the review! Really excited to get this PR in.

Thanks for the contribution. Instead of what you've done here, let's change the if in line 96 to first check parameters.Get(sslMode) and avoid setting the mode if a user provided a specific mode.

I'm sorry. I'm a bit confused by this. On line 96 parameters.Get(sslMode) should always be "" since we haven't set it yet. Do you mean checking cfg.ConnectAttributes[sslMode]?

Yes, that's what I meant. Sorry for the confusion.