Add 'Project.provide()' for virtual packages

lib/omnibus/packagers/deb.rb

@@ -319,6 +319,7 @@ def write_control_file
           section:        section,
           conflicts:      project.conflicts,
           replaces:       project.replaces,
+          provides:       project.provides,
           dependencies:   project.runtime_dependencies,
         }
       )

lib/omnibus/packagers/rpm.rb

@@ -374,6 +374,7 @@ def write_rpm_spec
           category:        category,
           conflicts:       project.conflicts,
           replaces:        project.replaces,
+          provides:        project.provides,
           dependencies:    project.runtime_dependencies,
           user:            project.package_user,
           group:           project.package_group,

lib/omnibus/project.rb

@@ -285,6 +285,23 @@ def description(val = NULL)
     end
     expose :description
 
+    #
+    # Add to the list of packages this one provides.
+    #
+    # @example
+    #   provide 'the-virtual-package'
+    #
+    # @param [String] val
+    #   the name of the package to provide
+    #
+    # @return [String]
+    #
+    def provide(val = NULL)
+      provides << val
+      provides.dup
+    end
+    expose :provide
+
     #
     # Add to the list of packages this one replaces.
     #
@@ -897,6 +914,15 @@ def replaces
       @replaces ||= []
     end
 
+    #
+    # The list of things this project provides.
+    #
+    # @return [Array<String>]
+    #
+    def provides
+      @provides ||= []
+    end
+
     #
     # The list of exclusions for this project.
     #

resources/deb/control.erb

@@ -14,6 +14,9 @@ Conflicts: <%= conflicts.join(', ') %>
 <% unless replaces.empty? -%>
 Replaces: <%= replaces.join(', ') %>
 <% end -%>
+<% unless provides.empty? -%>
+Provides: <%= provides.join(', ') %>
+<% end -%>
 Section: <%= section %>
 Priority: <%= priority %>
 Homepage: <%= homepage %>

spec/unit/packagers/deb_spec.rb

@@ -10,6 +10,7 @@ module Omnibus
         project.build_version("1.2.3")
         project.build_iteration("2")
         project.maintainer("Chef Software")
+        project.provide("chefy-package")
         project.license(project_license) if project_license
       end
     end
@@ -178,6 +179,7 @@ module Omnibus
         expect(contents).to include("Vendor: Omnibus <omnibus@getchef.com>")
         expect(contents).to include("Architecture: amd64")
         expect(contents).to include("Maintainer: Chef Software")
+        expect(contents).to include("Provides: chefy-package")
         expect(contents).to include("Installed-Size: 0")
         expect(contents).to include("Section: misc")
         expect(contents).to include("Priority: extra")

spec/unit/packagers/rpm_spec.rb

@@ -11,6 +11,7 @@ module Omnibus
         project.build_iteration("2")
         project.maintainer("Chef Software")
         project.replace("old-project")
+        project.provide("chefy-package")
         project.license(project_license) if project_license
       end
     end

spec/unit/project_spec.rb

@@ -28,6 +28,7 @@ module Omnibus
     it_behaves_like "a cleanroom setter", :homepage, %{homepage 'https://getchef.com'}
     it_behaves_like "a cleanroom setter", :description, %{description 'Installs the thing'}
     it_behaves_like "a cleanroom setter", :replace, %{replace 'old-chef'}
+    it_behaves_like "a cleanroom setter", :provide, %{provide 'chefy-package'}
     it_behaves_like "a cleanroom setter", :conflict, %{conflict 'puppet'}
     it_behaves_like "a cleanroom setter", :build_version, %{build_version '1.2.3'}
     it_behaves_like "a cleanroom setter", :build_iteration, %{build_iteration 1}