add deb-trigger, fix deb-after-purge, misc. lintian fixes

docs/snippets.rst

@@ -0,0 +1,8 @@
+Snippets For Argument Usage
+=========
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   snippets/*

docs/snippets/triggered.rst

@@ -0,0 +1,88 @@
+Debian Triggers
+===============
+
+Debian packages can install commands to be run after installation and configuration of all packages.
+Those commands are called triggers as other packages can ask the package manager to run those.
+
+Sample trigger script
+---------------------
+
+This script defines two triggers. First the label based trigger `some-trigger` which runs `some-command`. Second the path based trigger `/etc/foobar` which runs a find-command.
+
+::
+
+  for trigger in "$@"; do
+    case "$trigger" in
+      some-trigger)
+        some-command
+      ;;
+      /etc/foobar)
+        find /etc/foobar -type f -ls
+      ;;
+    esac
+  done
+
+Install trigger
+---------------
+
+The following fpm command installs the trigger:
+
+    fpm --triggered /path/to/triggers.sh
+
+The resulting postinst-script in the packages looks like this:
+
+::
+
+  #!/bin/sh
+
+  after_upgrade() {
+      :
+  }
+
+  after_install() {
+      :
+  }
+
+  triggered() {
+      :
+  for trigger in "$@"; do
+    case "$trigger" in
+      some-trigger)
+        some-command
+      ;;
+      /etc/foobar)
+        find /etc/foobar -type f -ls
+      ;;
+    esac
+  done
+  }
+
+  if [ "${1}" = "configure" -a -z "${2}" ] || \
+     [ "${1}" = "abort-remove" ]
+  then
+      # "after install" here
+      # "abort-remove" happens when the pre-removal script failed.
+      #   In that case, this script, which should be idemptoent, is run
+      #   to ensure a clean roll-back of the removal.
+      after_install
+  elif [ "${1}" = "configure" -a -n "${2}" ]
+  then
+      upgradeFromVersion="${2}"
+      # "after upgrade" here
+      # NOTE: This slot is also used when deb packages are removed,
+      # but their config files aren't, but a newer version of the
+      # package is installed later, called "Config-Files" state.
+      # basically, that still looks a _lot_ like an upgrade to me.
+      after_upgrade "${2}"
+  elif [ "${1}" = "triggered" ]
+  then
+      # "triggered" here
+      # NOTE: This slot allows implementing package triggers according to
+      # https://wiki.debian.org/DpkgTriggers
+      shift
+      triggered "${@}"
+  elif echo "${1}" | grep -E -q "(abort|fail)"
+  then
+      echo "Failed to install before the post-installation script was run." >&2
+      exit 1
+  fi

lib/fpm/command.rb

@@ -213,6 +213,13 @@ def help(*args)
     File.expand_path(val) # Get the full path to the script
   end # --before-upgrade
 
+  option "--triggered", "FILE",
+    "A script snippets to define and run package triggers, see\n" \
+    "https://wiki.debian.org/DpkgTriggers and\n" \
+    "https://stackoverflow.com/questions/15276535/dpkg-how-to-use-trigger\n" do |val|
+    File.expand_path(val) # Get the full path to the script
+  end # --triggered
+
   option "--template-scripts", :flag,
     "Allow scripts to be templated. This lets you use ERB to template your " \
     "packaging scripts (for --after-install, etc). For example, you can do " \
@@ -466,6 +473,7 @@ def execute
     setscript.call(:after_remove)
     setscript.call(:before_upgrade)
     setscript.call(:after_upgrade)
+    setscript.call(:triggered)
 
     # Bail if any setscript calls had errors. We don't need to log
     # anything because we've already logged the error(s) above.

lib/fpm/package/deb.rb

@@ -527,15 +527,15 @@ def output(output_path)
       attributes[:deb_systemd] << name
     end
 
-    if script?(:before_upgrade) or script?(:after_upgrade) or attributes[:deb_systemd].any?
+    if script?(:before_upgrade) or script?(:after_upgrade) or attributes[:deb_systemd].any? or script?(:triggered)
       puts "Adding action files"
       if script?(:before_install) or script?(:before_upgrade)
         scripts[:before_install] = template("deb/preinst_upgrade.sh.erb").result(binding)
       end
       if script?(:before_remove) or not attributes[:deb_systemd].empty?
         scripts[:before_remove] = template("deb/prerm_upgrade.sh.erb").result(binding)
       end
-      if script?(:after_install) or script?(:after_upgrade) or attributes[:deb_systemd].any?
+      if script?(:after_install) or script?(:after_upgrade) or attributes[:deb_systemd].any? or script?(:triggered)
         scripts[:after_install] = template("deb/postinst_upgrade.sh.erb").result(binding)
       end
       if script?(:after_remove)
@@ -593,7 +593,9 @@ def output(output_path)
 
     if File.exists?(dest_changelog) and not File.exists?(dest_upstream_changelog)
       # see https://www.debian.org/doc/debian-policy/ch-docs.html#s-changelogs
-      File.rename(dest_changelog, dest_upstream_changelog)
+      # to solve Lintian rule debian-changelog-file-missing-or-wrong-name the file
+      # is copied and not renamed
+      FileUtils.cp(dest_changelog, dest_upstream_changelog)
     end
 
     attributes.fetch(:deb_init_list, []).each do |init|

templates/deb/postinst_upgrade.sh.erb

@@ -60,6 +60,13 @@ $debsystemctl start <%= service %> >/dev/null || true
 <% end -%>
 }
 
+triggered() {
+  : # Ensure this if-clause is not empty. If it were empty, and we had an 'else', then it is an error in shell syntax
+<% if script?(:triggered) -%>
+<%=  script(:triggered) %>
+<% end -%>
+}
+
 if [ "${1}" = "configure" -a -z "${2}" ] || \
    [ "${1}" = "abort-remove" ]
 then
@@ -77,6 +84,13 @@ then
     # package is installed later, called "Config-Files" state.
     # basically, that still looks a _lot_ like an upgrade to me.
     after_upgrade "${2}"
+elif [ "${1}" = "triggered" ]
+then
+    # "triggered" here
+    # NOTE: This slot allows implementing package triggers according to
+    # https://wiki.debian.org/DpkgTriggers
+    shift
+    triggered "${@}"
 elif echo "${1}" | grep -E -q "(abort|fail)"
 then
     echo "Failed to install before the post-installation script was run." >&2