Initial inst-sys cleanup client

src/lib/installation/clients/inst_instsys_cleanup.rb

@@ -0,0 +1,89 @@
+# ------------------------------------------------------------------------------
+# Copyright (c) 2016 SUSE LLC, All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of version 2 of the GNU General Public License as published by the
+# Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+# ------------------------------------------------------------------------------
+
+#
+
+require "fileutils"
+
+require "yast"
+require "yast2/hw_detection"
+
+module Yast
+  class InstInstsysCleanup < Client
+    # memory limit for removing the kernel modules from inst-sys (1GB)
+    MODULES_WATERMARK = 1 << 30
+
+    # memory limit for removing the libzypp metadata cache (640MB)
+    LIBZYPP_WATERMARK = 640 * (1 << 20)
+    LIBZYPP_CACHE_PATH = "/var/cache/zypp/raw".freeze
+
+    def main
+      textdomain "installation"
+
+      Yast.import "Mode"
+      Yast.import "Stage"
+
+      if !Stage.initial && (Mode.install || Mode.update)
+        log.warning("Skipping cleanup (not in the initial installation)")
+        return :auto
+      end
+
+      # memory size in MB
+      memory_mb = Yast2::HwDetection.memory << 20
+
+      # run the cleaning actions depending on the available memory
+
+      umount_kernel_modules if memory_mb < MODULES_WATERMARK
+
+      cleanup_zypp_cache if memory_mb < LIBZYPP_WATERMARK
+
+      :auto
+    end
+
+  private
+
+    # Remove the libzypp downloaded repository metadata.
+    # Libzypp has "raw" and "solv" caches, the "solv" is built from "raw"
+    # but it cannot be removed because libzypp keeps the file open.
+    # The "raw" files will be later downloaded again automatically when needed.
+    def cleanup_zypp_cache
+      log.info("inst-sys cleanup: removing libzypp cache (#{LIBZYPP_CACHE_PATH})")
+      log_space_usage("Before removing libzypp cache:")
+
+      # make sure we do not collide with Yast::FileUtils...
+      ::FileUtils.rm_rf(LIBZYPP_CACHE_PATH)
+
+      log_space_usage("After removing libzypp cache:")
+    end
+
+    def umount_kernel_modules
+      # TODO: verify that the modules are present
+      log.info("inst-sys cleanup: removing the kernel modules inst-sys image")
+      log_space_usage("Before removing kernel modules:")
+
+      # TODO: get the respective loop device name
+      # TODO: unmount the loop device
+      # TODO: remove the loop device setup (losetup -d)
+      # TODO: remove the image file
+
+      log_space_usage("After removing kernel modules:")
+    end
+
+    def log_space_usage(msg)
+      log.info(msg)
+      log.info("disk usage in MB ('df -m'):")
+      log.info(`df -m`)
+      log.info("memory usage in MB ('free -m'):")
+      log.info(`free -m`)
+    end
+  end
+end