Merge pull request #4888 from chef/lcg/multipackage-apt-provider

Make apt package provider use_multipackage_api aware

4 files changed, 207 insertions, 140 deletions

diff --git a/lib/chef/provider/package.rb b/lib/chef/provider/package.rb
index 6d67cdbbb2..cac0fb6eb0 100644
--- a/lib/chef/provider/package.rb
+++ b/lib/chef/provider/package.rb
@@ -596,7 +596,7 @@ class Chef
       # @param args [String] variable number of string arguments
       # @return [String] nicely concatenated string or empty string
       def a_to_s(*args)
-        args.reject { |i| i.nil? || i == "" }.join(" ")
+        args.flatten.reject { |i| i.nil? || i == "" }.join(" ")
       end
     end
   end
diff --git a/lib/chef/provider/package/apt.rb b/lib/chef/provider/package/apt.rb
index ac730202b8..8af089e14a 100644
--- a/lib/chef/provider/package/apt.rb
+++ b/lib/chef/provider/package/apt.rb
@@ -17,132 +17,64 @@
 #
 
 require "chef/provider/package"
-require "chef/mixin/command"
-require "chef/resource/package"
+require "chef/resource/apt_package"
 
 class Chef
   class Provider
     class Package
       class Apt < Chef::Provider::Package
+        use_multipackage_api
 
         provides :package, platform_family: "debian"
         provides :apt_package, os: "linux"
 
-        # return [Hash] mapping of package name to Boolean value
-        attr_accessor :is_virtual_package
-
         def initialize(new_resource, run_context)
           super
-          @is_virtual_package = {}
         end
 
         def load_current_resource
-          @current_resource = Chef::Resource::Package.new(@new_resource.name)
-          @current_resource.package_name(@new_resource.package_name)
-          check_all_packages_state(@new_resource.package_name)
-          @current_resource
+          @current_resource = Chef::Resource::AptPackage.new(new_resource.name)
+          current_resource.package_name(new_resource.package_name)
+          current_resource.version(get_current_versions)
+          current_resource
         end
 
         def define_resource_requirements
           super
 
           requirements.assert(:all_actions) do |a|
-            a.assertion { !@new_resource.source }
+            a.assertion { !new_resource.source }
             a.failure_message(Chef::Exceptions::Package, "apt package provider cannot handle source attribute. Use dpkg provider instead")
           end
         end
 
-        def default_release_options
-          # Use apt::Default-Release option only if provider supports it
-          "-o APT::Default-Release=#{@new_resource.default_release}" if @new_resource.respond_to?(:default_release) && @new_resource.default_release
+        def package_data
+          @package_data ||= Hash.new do |hash, key|
+            hash[key] = package_data_for(key)
+          end
         end
 
-        def check_package_state(pkg)
-          is_virtual_package = false
-          installed          = false
-          installed_version  = nil
-          candidate_version  = nil
-
-          shell_out_with_timeout!("apt-cache#{expand_options(default_release_options)} policy #{pkg}").stdout.each_line do |line|
-            case line
-            when /^\s{2}Installed: (.+)$/
-              installed_version = $1
-              if installed_version == "(none)"
-                Chef::Log.debug("#{@new_resource} current version is nil")
-                installed_version = nil
-              else
-                Chef::Log.debug("#{@new_resource} current version is #{installed_version}")
-                installed = true
-              end
-            when /^\s{2}Candidate: (.+)$/
-              candidate_version = $1
-              if candidate_version == "(none)"
-                # This may not be an appropriate assumption, but it shouldn't break anything that already worked -- btm
-                is_virtual_package = true
-                showpkg = shell_out_with_timeout!("apt-cache showpkg #{pkg}").stdout
-                providers = Hash.new
-                showpkg.rpartition(/Reverse Provides: ?#{$/}/)[2].each_line do |line|
-                  provider, version = line.split
-                  providers[provider] = version
-                end
-                # Check if the package providing this virtual package is installed
-                num_providers = providers.length
-                raise Chef::Exceptions::Package, "#{@new_resource.package_name} has no candidate in the apt-cache" if num_providers == 0
-                # apt will only install a virtual package if there is a single providing package
-                raise Chef::Exceptions::Package, "#{@new_resource.package_name} is a virtual package provided by #{num_providers} packages, you must explicitly select one to install" if num_providers > 1
-                # Check if the package providing this virtual package is installed
-                Chef::Log.info("#{@new_resource} is a virtual package, actually acting on package[#{providers.keys.first}]")
-                ret = check_package_state(providers.keys.first)
-                installed = ret[:installed]
-                installed_version = ret[:installed_version]
-              else
-                Chef::Log.debug("#{@new_resource} candidate version is #{$1}")
-              end
-            end
+        def get_current_versions
+          package_name_array.map do |package_name|
+            package_data[package_name][:current_version]
           end
-
-          return {
-            installed_version:   installed_version,
-            installed:           installed,
-            candidate_version:   candidate_version,
-            is_virtual_package:  is_virtual_package,
-          }
         end
 
-        def check_all_packages_state(package)
-          installed_version = {}
-          candidate_version = {}
-          installed = {}
-
-          [package].flatten.each do |pkg|
-            ret = check_package_state(pkg)
-            is_virtual_package[pkg] = ret[:is_virtual_package]
-            installed[pkg]          = ret[:installed]
-            installed_version[pkg]  = ret[:installed_version]
-            candidate_version[pkg]  = ret[:candidate_version]
+        def get_candidate_versions
+          package_name_array.map do |package_name|
+            package_data[package_name][:candidate_version]
           end
+        end
 
-          if package.is_a?(Array)
-            @candidate_version = []
-            final_installed_version = []
-            [package].flatten.each do |pkg|
-              @candidate_version << candidate_version[pkg]
-              final_installed_version << installed_version[pkg]
-            end
-            @current_resource.version(final_installed_version)
-          else
-            @candidate_version = candidate_version[package]
-            @current_resource.version(installed_version[package])
-          end
+        def candidate_version
+          @candidate_version ||= get_candidate_versions
         end
 
         def install_package(name, version)
-          name_array = [ name ].flatten
-          version_array = [ version ].flatten
-          package_name = name_array.zip(version_array).map do |n, v|
-            is_virtual_package[n] ? n : "#{n}=#{v}"
-          end.join(" ")
-          run_noninteractive("apt-get -q -y#{expand_options(default_release_options)}#{expand_options(@new_resource.options)} install #{package_name}")
+          package_name = name.zip(version).map do |n, v|
+            package_data[n][:virtual] ? n : "#{n}=#{v}"
+          end
+          run_noninteractive("apt-get -q -y", default_release_options, new_resource.options, "install", package_name)
         end
 
         def upgrade_package(name, version)
@@ -150,24 +82,27 @@ class Chef
         end
 
         def remove_package(name, version)
-          package_name = [ name ].flatten.join(" ")
-          run_noninteractive("apt-get -q -y#{expand_options(@new_resource.options)} remove #{package_name}")
+          package_name = name.map do |n|
+            package_data[n][:virtual] ? resolve_virtual_package_name(n) : n
+          end
+          run_noninteractive("apt-get -q -y", new_resource.options, "remove", package_name)
         end
 
         def purge_package(name, version)
-          package_name = [ name ].flatten.join(" ")
-          run_noninteractive("apt-get -q -y#{expand_options(@new_resource.options)} purge #{package_name}")
+          package_name = name.map do |n|
+            package_data[n][:virtual] ? resolve_virtual_package_name(n) : n
+          end
+          run_noninteractive("apt-get -q -y", new_resource.options, "purge", package_name)
         end
 
         def preseed_package(preseed_file)
-          Chef::Log.info("#{@new_resource} pre-seeding package installation instructions")
-          run_noninteractive("debconf-set-selections #{preseed_file}")
+          Chef::Log.info("#{new_resource} pre-seeding package installation instructions")
+          run_noninteractive("debconf-set-selections", preseed_file)
         end
 
         def reconfig_package(name, version)
-          package_name = [ name ].flatten.join(" ")
-          Chef::Log.info("#{@new_resource} reconfiguring")
-          run_noninteractive("dpkg-reconfigure #{package_name}")
+          Chef::Log.info("#{new_resource} reconfiguring")
+          run_noninteractive("dpkg-reconfigure", name)
         end
 
         private
@@ -175,8 +110,67 @@ class Chef
         # Runs command via shell_out with magic environment to disable
         # interactive prompts. Command is run with default localization rather
         # than forcing locale to "C", so command output may not be stable.
-        def run_noninteractive(command)
-          shell_out_with_timeout!(command, :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil })
+        def run_noninteractive(*args)
+          shell_out_with_timeout!(a_to_s(*args), :env => { "DEBIAN_FRONTEND" => "noninteractive" })
+        end
+
+        def default_release_options
+          # Use apt::Default-Release option only if provider supports it
+          "-o APT::Default-Release=#{new_resource.default_release}" if new_resource.respond_to?(:default_release) && new_resource.default_release
+        end
+
+        def resolve_package_versions(pkg)
+          current_version = nil
+          candidate_version = nil
+          run_noninteractive("apt-cache", default_release_options, "policy", pkg).stdout.each_line do |line|
+            case line
+            when /^\s{2}Installed: (.+)$/
+              current_version = ( $1 != "(none)" ) ? $1 : nil
+              Chef::Log.debug("#{new_resource} installed version for #{pkg} is #{$1}")
+            when /^\s{2}Candidate: (.+)$/
+              candidate_version = ( $1 != "(none)" ) ? $1 : nil
+              Chef::Log.debug("#{new_resource} candidate version for #{pkg} is #{$1}")
+            end
+          end
+          [ current_version, candidate_version ]
+        end
+
+        def resolve_virtual_package_name(pkg)
+          showpkg = run_noninteractive("apt-cache showpkg", pkg).stdout
+          partitions = showpkg.rpartition(/Reverse Provides: ?#{$/}/)
+          return nil if partitions[0] == "" && partitions[1] == "" # not found in output
+          set = partitions[2].lines.each_with_object(Set.new) do |line, acc|
+            # there may be multiple reverse provides for a single package
+            acc.add(line.split[0])
+          end
+          if set.size > 1
+            raise Chef::Exceptions::Package, "#{new_resource.package_name} is a virtual package provided by multiple packages, you must explicitly select one"
+          end
+          return set.to_a.first
+        end
+
+        def package_data_for(pkg)
+          virtual           = false
+          current_version   = nil
+          candidate_version = nil
+
+          current_version, candidate_version = resolve_package_versions(pkg)
+
+          if candidate_version.nil?
+            newpkg = resolve_virtual_package_name(pkg)
+
+            if newpkg
+              virtual = true
+              Chef::Log.info("#{new_resource} is a virtual package, actually acting on package[#{newpkg}]")
+              current_version, candidate_version = resolve_package_versions(newpkg)
+            end
+          end
+
+          return {
+            current_version:    current_version,
+            candidate_version:  candidate_version,
+            virtual:            virtual,
+          }
         end
 
       end
diff --git a/spec/unit/provider/package/apt_spec.rb b/spec/unit/provider/package/apt_spec.rb
index b5f0646b79..a549ecc72e 100644
--- a/spec/unit/provider/package/apt_spec.rb
+++ b/spec/unit/provider/package/apt_spec.rb
@@ -52,6 +52,7 @@ irssi:
         it "should create a current resource with the name of the new_resource" do
           expect(@provider).to receive(:shell_out!).with(
             "apt-cache policy #{@new_resource.package_name}",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
             :timeout => @timeout
           ).and_return(@shell_out)
           @provider.load_current_resource
@@ -60,7 +61,7 @@ irssi:
           expect(current_resource).to be_a(Chef::Resource::Package)
           expect(current_resource.name).to eq("irssi")
           expect(current_resource.package_name).to eq("irssi")
-          expect(current_resource.version).to be_nil
+          expect(current_resource.version).to eql([nil])
         end
 
         it "should set the installed version if package has one" do
@@ -78,8 +79,32 @@ sudo:
           INSTALLED
           expect(@provider).to receive(:shell_out!).and_return(@shell_out)
           @provider.load_current_resource
-          expect(@provider.current_resource.version).to eq("1.7.2p1-1ubuntu5.3")
-          expect(@provider.candidate_version).to eql("1.7.2p1-1ubuntu5.3")
+          expect(@provider.current_resource.version).to eq(["1.7.2p1-1ubuntu5.3"])
+          expect(@provider.candidate_version).to eql(["1.7.2p1-1ubuntu5.3"])
+        end
+
+        # it is the superclasses responsibility to throw most exceptions
+        it "if the package does not exist in the cache sets installed + candidate version to nil" do
+          @new_resource.package_name("conic-smarms")
+          policy_out = <<-POLICY_STDOUT
+N: Unable to locate package conic-smarms
+          POLICY_STDOUT
+          policy = double(:stdout => policy_out, :exitstatus => 0)
+          expect(@provider).to receive(:shell_out!).with(
+            "apt-cache policy conic-smarms",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
+            :timeout => @timeout
+          ).and_return(policy)
+          showpkg_out = <<-SHOWPKG_STDOUT
+N: Unable to locate package conic-smarms
+          SHOWPKG_STDOUT
+          showpkg = double(:stdout => showpkg_out, :exitstatus => 0)
+          expect(@provider).to receive(:shell_out!).with(
+            "apt-cache showpkg conic-smarms",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
+            :timeout => @timeout
+          ).and_return(showpkg)
+          @provider.load_current_resource
         end
 
         # libmysqlclient-dev is a real package in newer versions of debian + ubuntu
@@ -95,6 +120,7 @@ libmysqlclient15-dev:
           virtual_package = double(:stdout => virtual_package_out, :exitstatus => 0)
           expect(@provider).to receive(:shell_out!).with(
             "apt-cache policy libmysqlclient15-dev",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
             :timeout => @timeout
           ).and_return(virtual_package)
           showpkg_out = <<-SHOWPKG_STDOUT
@@ -118,6 +144,7 @@ libmysqlclient-dev 5.1.41-3ubuntu12
           showpkg = double(:stdout => showpkg_out, :exitstatus => 0)
           expect(@provider).to receive(:shell_out!).with(
             "apt-cache showpkg libmysqlclient15-dev",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
             :timeout => @timeout
           ).and_return(showpkg)
           real_package_out = <<-RPKG_STDOUT
@@ -136,6 +163,7 @@ libmysqlclient-dev:
           real_package = double(:stdout => real_package_out, :exitstatus => 0)
           expect(@provider).to receive(:shell_out!).with(
             "apt-cache policy libmysqlclient-dev",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
             :timeout => @timeout
           ).and_return(real_package)
           @provider.load_current_resource
@@ -152,6 +180,7 @@ mp3-decoder:
           virtual_package = double(:stdout => virtual_package_out, :exitstatus => 0)
           expect(@provider).to receive(:shell_out!).with(
             "apt-cache policy mp3-decoder",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
             :timeout => @timeout
           ).and_return(virtual_package)
           showpkg_out = <<-SHOWPKG_STDOUT
@@ -178,6 +207,7 @@ mpg123 1.12.1-0ubuntu1
           showpkg = double(:stdout => showpkg_out, :exitstatus => 0)
           expect(@provider).to receive(:shell_out!).with(
             "apt-cache showpkg mp3-decoder",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
             :timeout => @timeout
           ).and_return(showpkg)
           expect { @provider.load_current_resource }.to raise_error(Chef::Exceptions::Package)
@@ -191,6 +221,7 @@ mpg123 1.12.1-0ubuntu1
           allow(@new_resource).to receive(:provider).and_return(nil)
           expect(@provider).to receive(:shell_out!).with(
             "apt-cache -o APT::Default-Release=lenny-backports policy irssi",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" },
             :timeout => @timeout
           ).and_return(@shell_out)
           @provider.load_current_resource
@@ -200,11 +231,9 @@ mpg123 1.12.1-0ubuntu1
           @new_resource.source "pluto"
           expect(@provider).to receive(:shell_out!).with(
             "apt-cache policy #{@new_resource.package_name}",
+            :env => { "DEBIAN_FRONTEND" => "noninteractive" } ,
             :timeout => @timeout
           ).and_return(@shell_out)
-          @provider.load_current_resource
-          @provider.define_resource_requirements
-          expect(@provider).to receive(:shell_out!).with("apt-cache policy irssi", { :timeout => 900 }).and_return(@shell_out)
           expect { @provider.run_action(:install) }.to raise_error(Chef::Exceptions::Package)
         end
       end
@@ -213,26 +242,38 @@ mpg123 1.12.1-0ubuntu1
         before do
           @current_resource = resource_klass.new("irssi", @run_context)
           @provider.current_resource = @current_resource
+          allow(@provider).to receive(:package_data).and_return({
+            "irssi" => {
+              virtual: false,
+              candidate_version: "0.8.12-7",
+              installed_version: nil,
+            },
+            "libmysqlclient15-dev" => {
+              virtual: true,
+              candidate_version: nil,
+              installed_version: nil,
+            },
+          })
         end
 
         describe "install_package" do
           it "should run apt-get install with the package name and version" do
             expect(@provider).to receive(:shell_out!). with(
               "apt-get -q -y install irssi=0.8.12-7",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
-            @provider.install_package("irssi", "0.8.12-7")
+            @provider.install_package(["irssi"], ["0.8.12-7"])
           end
 
           it "should run apt-get install with the package name and version and options if specified" do
             expect(@provider).to receive(:shell_out!).with(
               "apt-get -q -y --force-yes install irssi=0.8.12-7",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
             @new_resource.options("--force-yes")
-            @provider.install_package("irssi", "0.8.12-7")
+            @provider.install_package(["irssi"], ["0.8.12-7"])
           end
 
           it "should run apt-get install with the package name and version and default_release if there is one and provider is explicitly defined" do
@@ -244,19 +285,19 @@ mpg123 1.12.1-0ubuntu1
 
             expect(@provider).to receive(:shell_out!).with(
               "apt-get -q -y -o APT::Default-Release=lenny-backports install irssi=0.8.12-7",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
 
-            @provider.install_package("irssi", "0.8.12-7")
+            @provider.install_package(["irssi"], ["0.8.12-7"])
           end
         end
 
         describe resource_klass, "upgrade_package" do
 
           it "should run install_package with the name and version" do
-            expect(@provider).to receive(:install_package).with("irssi", "0.8.12-7")
-            @provider.upgrade_package("irssi", "0.8.12-7")
+            expect(@provider).to receive(:install_package).with(["irssi"], ["0.8.12-7"])
+            @provider.upgrade_package(["irssi"], ["0.8.12-7"])
           end
         end
 
@@ -265,21 +306,21 @@ mpg123 1.12.1-0ubuntu1
           it "should run apt-get remove with the package name" do
             expect(@provider).to receive(:shell_out!).with(
               "apt-get -q -y remove irssi",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
-            @provider.remove_package("irssi", "0.8.12-7")
+            @provider.remove_package(["irssi"], ["0.8.12-7"])
           end
 
           it "should run apt-get remove with the package name and options if specified" do
             expect(@provider).to receive(:shell_out!).with(
               "apt-get -q -y --force-yes remove irssi",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
             @new_resource.options("--force-yes")
 
-            @provider.remove_package("irssi", "0.8.12-7")
+            @provider.remove_package(["irssi"], ["0.8.12-7"])
           end
         end
 
@@ -288,21 +329,21 @@ mpg123 1.12.1-0ubuntu1
           it "should run apt-get purge with the package name" do
             expect(@provider).to receive(:shell_out!).with(
               "apt-get -q -y purge irssi",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
-            @provider.purge_package("irssi", "0.8.12-7")
+            @provider.purge_package(["irssi"], ["0.8.12-7"])
           end
 
           it "should run apt-get purge with the package name and options if specified" do
             expect(@provider).to receive(:shell_out!).with(
               "apt-get -q -y --force-yes purge irssi",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
             @new_resource.options("--force-yes")
 
-            @provider.purge_package("irssi", "0.8.12-7")
+            @provider.purge_package(["irssi"], ["0.8.12-7"])
           end
         end
 
@@ -316,7 +357,7 @@ mpg123 1.12.1-0ubuntu1
 
             expect(@provider).to receive(:shell_out!).with(
               "debconf-set-selections /tmp/irssi-0.8.12-7.seed",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
 
@@ -326,7 +367,7 @@ mpg123 1.12.1-0ubuntu1
           it "should run debconf-set-selections on the preseed file if it has changed" do
             expect(@provider).to receive(:shell_out!).with(
               "debconf-set-selections /tmp/irssi-0.8.12-7.seed",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
             file = @provider.get_preseed_file("irssi", "0.8.12-7")
@@ -347,7 +388,7 @@ mpg123 1.12.1-0ubuntu1
           it "should run dpkg-reconfigure package" do
             expect(@provider).to receive(:shell_out!).with(
               "dpkg-reconfigure irssi",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
             @provider.reconfig_package("irssi", "0.8.12-7")
@@ -356,27 +397,49 @@ mpg123 1.12.1-0ubuntu1
 
         describe "when installing a virtual package" do
           it "should install the package without specifying a version" do
-            @provider.is_virtual_package["libmysqlclient-dev"] = true
+            @provider.package_data["libmysqlclient15-dev"][:virtual] = true
+            expect(@provider).to receive(:shell_out!).with(
+              "apt-get -q -y install libmysqlclient15-dev",
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
+              :timeout => @timeout
+            )
+            @provider.install_package(["libmysqlclient15-dev"], ["not_a_real_version"])
+          end
+        end
+
+        describe "when removing a virtual package" do
+          it "should remove the resolved name instead of the virtual package name" do
+            expect(@provider).to receive(:resolve_virtual_package_name).with("libmysqlclient15-dev").and_return("libmysqlclient-dev")
+            expect(@provider).to receive(:shell_out!).with(
+              "apt-get -q -y remove libmysqlclient-dev",
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
+              :timeout => @timeout
+            )
+            @provider.remove_package(["libmysqlclient15-dev"], ["not_a_real_version"])
+          end
+        end
+
+        describe "when purging a virtual package" do
+          it "should purge the resolved name instead of the virtual package name" do
+            expect(@provider).to receive(:resolve_virtual_package_name).with("libmysqlclient15-dev").and_return("libmysqlclient-dev")
             expect(@provider).to receive(:shell_out!).with(
-              "apt-get -q -y install libmysqlclient-dev",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              "apt-get -q -y purge libmysqlclient-dev",
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
-            @provider.install_package("libmysqlclient-dev", "not_a_real_version")
+            @provider.purge_package(["libmysqlclient15-dev"], ["not_a_real_version"])
           end
         end
 
         describe "when installing multiple packages" do
           it "can install a virtual package followed by a non-virtual package" do
             # https://github.com/chef/chef/issues/2914
-            @provider.is_virtual_package["libmysqlclient-dev"] = true
-            @provider.is_virtual_package["irssi"] = false
             expect(@provider).to receive(:shell_out!).with(
-              "apt-get -q -y install libmysqlclient-dev irssi=0.8.12-7",
-              :env => { "DEBIAN_FRONTEND" => "noninteractive", "LC_ALL" => nil },
+              "apt-get -q -y install libmysqlclient15-dev irssi=0.8.12-7",
+              :env => { "DEBIAN_FRONTEND" => "noninteractive" },
               :timeout => @timeout
             )
-            @provider.install_package(["libmysqlclient-dev", "irssi"], ["not_a_real_version", "0.8.12-7"])
+            @provider.install_package(["libmysqlclient15-dev", "irssi"], ["not_a_real_version", "0.8.12-7"])
           end
         end
 
diff --git a/spec/unit/provider/package_spec.rb b/spec/unit/provider/package_spec.rb
index e4354d0db4..2ef58db9f3 100644
--- a/spec/unit/provider/package_spec.rb
+++ b/spec/unit/provider/package_spec.rb
@@ -458,8 +458,18 @@ describe "Subclass with use_multipackage_api" do
     expect(provider.use_multipackage_api?).to be true
   end
 
-  it "offers a_to_s to subclasses to convert an array of strings to a single string" do
-    expect(provider.send(:a_to_s, "a", nil, "b", "", "c", " ", "d e", "f-g")).to eq("a b c   d e f-g")
+  context "#a_to_s utility for subclasses" do
+    it "converts varargs of strings to a single string" do
+      expect(provider.send(:a_to_s, "a", nil, "b", "", "c", " ", "d e", "f-g")).to eq("a b c   d e f-g")
+    end
+
+    it "converts an array of strings to a single string" do
+      expect(provider.send(:a_to_s, ["a", nil, "b", "", "c", " ", "d e", "f-g"])).to eq("a b c   d e f-g")
+    end
+
+    it "converts a mishmash of array args to a single string" do
+      expect(provider.send(:a_to_s, "a", [ nil, "b", "", [ "c" ] ], " ", [ "d e", "f-g" ])).to eq("a b c   d e f-g")
+    end
   end
 
   it "when user passes string to package_name, passes arrays to install_package" do