[rpms/fedora-release] f45: add the lua script

[rpms/fedora-release] f45: add the lua script

[Dennis Gilmore]

            A new commit has been pushed.

            Repo   : rpms/fedora-release
            Branch : f45
            Commit : 71d7061ffbf4c2d231485359e06fac80f34ea40c
            Author : Dennis Gilmore <dennis@ausil.us>
            Date   : 2016-03-08T16:23:13-06:00
            Stats  : +179/-0 in 1 file(s)
            URL    : https://src.fedoraproject.org/rpms/fedora-release/c/71d7061ffbf4c2d231485359e06fac80f34ea40c?branch=f45

            Log:
            add the lua script

Signed-off-by: Dennis Gilmore <dennis@ausil.us>

---
diff --git a/convert-to-edition.lua b/convert-to-edition.lua
new file mode 100644
index 0000000..f10c3cc
--- /dev/null
+++ b/convert-to-edition.lua
@@ -0,0 +1,179 @@
+-- This is intended to be run as an RPM scriptlet.
+-- Keep this file in sync with the convert-to-edition
+-- shell script
+
+local VARIANT_FILE = "/usr/lib/variant"
+
+-- Read in /usr/lib/variant and determine the edition
+local function read_variant()
+  local variant
+  local f = io.open("/usr/lib/variant", "r")
+  if f ~= nil then
+    while true do
+      local line = f:read()
+      if line == nil then
+        break
+      end
+      local m = line:match("^VARIANT_ID=([^\n]+)")
+      if m ~= nil then
+        variant = m
+      end
+    end
+  end
+  return variant
+end
+
+-- Atomically replace a file with new contents
+local function writefile(path, data)
+  local tmp = path .. ".convert-to-edition"
+  local f = io.open(tmp, "w+")
+  if f == nil then
+    return
+  end
+  f:write(data)
+  f:close()
+  if not os.rename(tmp, path) then
+    os.remove(tmp)
+  end
+end
+
+-- Forcibly replace a symlink
+local function symlink(from, to)
+  os.remove(to)
+  assert(posix.symlink(from, to))
+end
+
+-- Run a subroutine in a child process
+local function execute(...)
+  local pid = posix.fork()
+  if pid == 0 then
+    posix.exec(...)
+    posix.exit(1)
+  elseif pid ~= -1 then
+    local status = posix.wait(pid)
+    if status ~= 0 then
+      local program = ...
+      error(program .. " exited with status " .. status)
+    end
+  end
+end
+
+-- Remove preset files for other editions
+-- This should never be necessary, but it's best to be safe
+local function clear_presets()
+  local path = "/usr/lib/systemd/system-preset"
+  for file in posix.files(path) do
+    if file:match("^80-.*%.preset$") then
+      os.remove(path .. "/" .. file)
+    end
+  end
+end
+
+
+-- Get a list of presets that need to be enabled or disabled
+-- as part of the installation of this edition
+local function read_presets(path)
+  local result = {}
+  local f = assert(io.open(path))
+  if f ~= nil then
+    while true do
+      local line = f:read()
+      if line == nil then
+        break
+      end
+      local cmd, arg = line:match("^([^ \t]+)[ \t]+([^\n \t]+)")
+      if cmd == "enable" or cmd == "disable" then
+        result[#result + 1] = arg
+      end
+      f:close()
+    end
+  end
+  return result
+end
+
+local function set_variant(variant)
+  writefile(VARIANT_FILE, "VARIANT_ID=" .. variant .. "\n")
+end
+
+local function set_release(release)
+  symlink("./os.release.d/os-release-" .. release, "/usr/lib/os-release")
+end
+
+local function set_issue(release)
+  symlink("./os.release.d/issue-" .. release, "/usr/lib/issue")
+end
+-- release: the VARIANT_ID for os-release
+-- issue: which /etc/issue file to install
+-- presets: whether this edition has extra presets beyond the
+--          defaults to enable or disable
+local variants = {
+  atomichost = {release = "atomichost", issue = "fedora", presets = false},
+  cloud = {release = "cloud", issue = "fedora", presets = false},
+  nonproduct = {release = "fedora", issue = "fedora", presets = false},
+  server = {release = "server", issue = "server", presets = true},
+  workstation = {release = "workstation", issue = "fedora", presets = true},
+}
+
+-- Call out to systemctl to enable or disable presets
+local function set_presets(edition)
+  if variants[edition].presets then
+    local target = "/usr/lib/systemd/system-preset/80-" .. edition .. ".preset"
+    symlink("../../os.edition.d/presets/80-" .. edition .. ".preset", target)
+    local presets = read_presets(target)
+	local systemctl = "/usr/bin/systemctl"
+	if posix.access(systemctl, "x") then
+      os.execute(systemctl, "preset", "-q",
+                 table.unpack(presets))
+	end
+  end
+end
+
+local function convert_to_edition(edition, do_presets)
+  local variant = variants[edition]
+  if variant == nil then
+    error("undefined edition: " .. edition)
+  end
+  set_release(variant.release)
+  set_issue(variant.issue)
+  clear_presets()
+
+  if do_presets then
+    set_presets(edition)
+  end
+
+  local grub = "/usr/sbin/grub2-mkconfig"
+  if posix.access(grub, "x") then
+    execute(grub, "-o", "/boot/grub2/grub.cfg")
+  end
+end
+
+local function install_edition(edition)
+  -- Create the variant file if it does not already exist. This needs
+  -- to be done on both installation and upgrade, to ensure that we
+  -- upgrade from F23 and earlier properly.
+  if not posix.access(VARIANT_FILE, "f") then
+    set_variant(edition)
+  end
+  if read_variant() == edition then
+    -- (On initial installation only), fix up after %%systemd_post
+    -- in packages possibly installed before our preset file was
+    -- added
+    -- On upgrades, do not enable or disable presets to avoid
+    -- surprising the user
+    local initial_install = arg[2] == "1"
+    convert_to_edition(edition, initial_install)
+  end
+end
+
+local function uninstall_edition(edition)
+  -- If we are uninstalling, we need to reset the variant file and
+  -- force the os-release file back to os-release-fedora.  We do this
+  -- in %%preun so that we don't have any time where the os-release
+  -- symlink is dangling (since in %%postun, the os-release-$EDITION
+  -- file will have already been removed)
+  if arg[2] == "0" then
+    if read_variant() == edition then
+      convert_to_edition("nonproduct", false)
+    end
+  end
+end