Enable reading SSL parameters from configuration file

[JAORMX]

This enables the reading of some basic SSL parameters from the
configuration file. It gives precedence to the ssl parameters provided
by the class parameter (the ssl dict).

[methane]

if not any(ssl.values())

And read_default_file option changes how ssl = {"ca": ""} is considered.
if read_default_file=False, ssl is overwritten to None. Otherwise, passed ssl is used as-is.
I don't like it.

[JAORMX]

Actually, this is for the if read_default_file: case. So it will only be read when that's set.

[methane]

Mabe, if ssl and any(ssl.values()).

[JAORMX]

@methane I updated the commit. What do you think?

[methane]

since you used _config when building ssl_config_params,
you can just ssl[key] = value

[JAORMX]

Using ssl[key] = value would overwrite the value that's already there, and this gives priority to the values that are set via the ssl dict.

[JAORMX]

That's why I added the comment above this for loop.

[methane]

read _config() function.

[JAORMX]

@methane you are right, I changed it accordingly.

[methane]

How about this?

for key in ["ca", "capath", "cert", "key", "cipher"]:
    value = cfg.get(read_default_group, "ssl-" + key)
    if value:
        ssl[key] = value

(I hadn't check mysql options yet.)

[methane]

I confirmed options have exactly same name.

[JAORMX]

@methane by the way, I see that in the _create_ssl_ctx function there is a check such as this:
if isinstance(sslp, ssl.SSLContext):
return sslp
should I take that into account as well?

[methane]

Ah, yes please. Use config only when dict is None or isinstance(ssl, dict)

[JAORMX]

@methane done; and I really liked your suggestion. I added the minimized loop you suggested as part of the change.

[JAORMX]

Tested it successfully in my deployment. @methane thanks for the great reviews. Let me know if there's anything else I should change.