Add --package-template-dir option to overwrite the spec by user's templates

[repeatedly]

From this thread: "How to specify own spec?" https://groups.google.com/forum/#!topic/fpm-users/GeH7xHhBo80

I didn't get the answer so I implemented this feature. To use --package-template-dir, we can specify full customized spec instead of bundled template.

[repeatedly]

@jordansissel Do you have any concern for this feature?

[jordansissel]

It is my intention to actually remove rpmbuild from fpm, so features allowing you to specify a custom specfile would become not useful after that. As long as you are comfortable with that, we can move forward knowing this feature will be removed as soon as write-capabilities are added to arr-pm library.

In terms of specifying your own spec, what is your use case? Can fpm solve this without requiring you to write and maintain an rpm spec?

[jordansissel]

For context - I can't find the ticket, but my intention is to make a pure-ruby rpm writer library. Today, we have reads, but not writes. The reason for this is that rpmbuild has several bugs and hazards that can't be fixed in old operating systems, and further we can implement things with better error messages if we don't use rpmbuild ;)

[repeatedly]

my intention is to make a pure-ruby rpm writer library.

Wow, I just knew this project: https://github.com/jordansissel/ruby-arr-pm It seems good :+1:

In terms of specifying your own spec, what is your use case? Can fpm solve this without requiring you to write and maintain an rpm spec?

Hm... I want to use more configuration of rpm / deb package. In rpm, config(replace,missingok), %define debug_package %{nil} and etc. In deb, Standards-Version and etc. Adding more options can resolve this problem but I think specifying own spec / control is more maintainable.

[jordansissel]

%define debug_package %{nil}

I don't know what this does, but you can use --rpm-rpmbuild-define to set this.

config(replace,missingok)

We could add a flag for this specific to RPM. FPM already has an idea of config files, so it shouldn't be hard to add specific settings to config file entries in the rpm spec based on fpm flags.

deb, Standards-Version

Can you describe a case where you would need to change this? I never set this field even when I was building debian packages 'the debian way'

[josephholsten]

@repeatedly I'd be happy to rebase this, but do we really want it? do you think fpm still needs spec support?