Avoid apt (dpkg) prompts for modified config files

2 files changed, 13 insertions, 1 deletions

diff --git a/lib/chef/provider/package/apt.rb b/lib/chef/provider/package/apt.rb
index 9eb8dd736a..ec9501a4b5 100644
--- a/lib/chef/provider/package/apt.rb
+++ b/lib/chef/provider/package/apt.rb
@@ -82,7 +82,7 @@ class Chef
           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, options, "install", package_name)
+          run_noninteractive("apt-get", "-q", "-y", config_file_options, default_release_options, options, "install", package_name)
         end
 
         def upgrade_package(name, version)
@@ -153,6 +153,17 @@ class Chef
           end
         end
 
+        def config_file_options
+          # It doesn't make sense to install packages in a scenario that can
+          # result in a prompt. Have users decide up-front whether they want to
+          # forcibly overwrite the config file, otherwise preserve it.
+          if new_resource.respond_to?(:overwrite_config_files) && new_resource.overwrite_config_files
+            '-o Dpkg::Options::="--force-confnew"'
+          else
+            '-o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"'
+          end
+        end
+
         def resolve_package_versions(pkg)
           current_version = nil
           candidate_version = nil
diff --git a/lib/chef/resource/apt_package.rb b/lib/chef/resource/apt_package.rb
index c077922a20..91c0e2836d 100644
--- a/lib/chef/resource/apt_package.rb
+++ b/lib/chef/resource/apt_package.rb
@@ -27,6 +27,7 @@ class Chef
       provides :package, os: "linux", platform_family: "debian"
 
       property :default_release, String, desired_state: false
+      property :overwrite_config_files, String, default: false
 
     end
   end