First version of classes for importing SSH configuration

src/lib/installation/ssh_config.rb

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+# 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 or 3 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.
+
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, contact SUSE LLC.
+
+#  To contact SUSE about this file by physical or electronic mail,
+#  you may find current contact information at www.suse.com
+
+require "installation/ssh_key"
+require "installation/ssh_config_file"
+
+module Installation
+  # Class that allows to memorize the list of SSH keys and config files found in
+  # a partition (i.e. the content of the /etc/ssh directory)
+  #
+  # Used by the SSH keys importing functionality.
+  #
+  # It provides class methods to hold a list of configurations
+  class SshConfig
+    DEFAULT_NAME = "Linux"
+
+    @all = []
+
+    class << self
+      # List of all the known configurations. Populated by .import.
+      # @see .import
+      # @see .export
+      def all
+        @all
+      end
+
+      # Imports ssh keys and config files from a given root directory and stores
+      # the information in the global list (.all)
+      #
+      # @param root_dir [String] Path where the original "/" is mounted
+      # @param device [String] Name of the mounted device
+      def import(root_dir, device)
+        config = from_dir(root_dir, device)
+        return if config.keys.empty? && config.config_files.empty?
+
+        @all << config
+      end
+
+      # Writes the selected ssh keys and config files in the ssh directory.
+      #
+      # Only files and keys with the flag #to_export? are written.
+      #
+      # @param root_dir [String] Path to use as "/" to locate the ssh directory
+      def export(root_dir)
+        dir = ssh_dir(root_dir)
+        all.each { |config| config.write_files(dir) }
+      end
+
+    protected
+
+      # Creates a new object with the information read from a directory
+      #
+      # @param root_dir [String] Path where the original "/" is mounted
+      # @param device [String] Name of the mounted device
+      def from_dir(root_dir, device)
+        config = SshConfig.new(name_for(root_dir), device)
+        dir = ssh_dir(root_dir)
+        config.read_files(dir)
+        config
+      end
+
+      def ssh_dir(root_dir)
+        File.join(root_dir, "etc", "ssh")
+      end
+
+      def os_release_file(root_dir)
+        File.join(root_dir, "etc", "os-release")
+      end
+
+      # Find out the name for a previous Linux installation.
+      # This uses /etc/os-release which is specified in
+      # https://www.freedesktop.org/software/systemd/man/os-release.html
+      #
+      # @param mount_point [String] Path where the original "/" is mounted
+      # @return [String] Speaking name of the Linux installation
+      #
+      def name_for(mount_point)
+        os_release = parse_ini_file(os_release_file(mount_point))
+        name = os_release["PRETTY_NAME"]
+        if name.empty? || name == DEFAULT_NAME
+          name = os_release[NAME] || DEFAULT_NAME
+          name += os_release[VERSION]
+        end
+        name
+      rescue Errno::ENOENT # No /etc/os-release found
+        DEFAULT_NAME
+      end
+
+      # Parse a simple .ini file and return the content in a hash.
+      #
+      # @param filename [String] Name of the file to parse
+      # @return [Hash<String, String>] file content as hash
+      #
+      def parse_ini_file(filename)
+        content = {}
+        File.readlines(filename).each do |line|
+          line = line.lstrip.chomp
+          next if line.empty? || line.start_with?("#")
+          (key, value) = line.split("=")
+          value.gsub!(/^\s*"/, "")
+          value.gsub!(/"\s*$/, "")
+          content[key] = value
+        end
+        content
+      end
+    end
+
+    # @return [String] name to help the user identify the configuration
+    attr_accessor :system_name
+    # @return [String] device name of the partition
+    attr_accessor :device
+    # @return [Array<SshKey>] keys found in the partition
+    attr_accessor :keys
+    # @return [Array<SshConfigFile>] configuration files found in the partition
+    attr_accessor :config_files
+
+    def initialize(system_name, device)
+      self.system_name = system_name
+      self.device = device
+      self.keys = []
+      self.config_files = []
+    end
+
+    # Populates the list of keys and config files from a ssh directory
+    #
+    # @param dir [String] path of the SSH directory
+    def read_files(dir)
+      filenames = Dir.glob("#{dir}/*")
+
+      # Let's process keys first, pairs of files like "xyz" & "xyz.pub"
+      pub_key_filenames = filenames.select { |f| f.end_with?(SshKey::PUBLIC_FILE_SUFFIX) }
+      pub_key_filenames.each do |pub_file|
+        # Remove the .pub suffix
+        priv_file = pub_file.chomp(SshKey::PUBLIC_FILE_SUFFIX)
+        add_key(priv_file)
+        filenames.delete(pub_file)
+        filenames.delete(priv_file)
+      end
+
+      filenames.each do |name|
+        add_config_file(name)
+      end
+    end
+
+    # Writes the files to a directory
+    #
+    # @param dir [String] path of the target SSH directory
+    def write_files(dir)
+      keys.select(&:to_export?).each do |key|
+        key.write_files(dir)
+      end
+      config_files.select(&:to_export?).each do |file|
+        file.write(dir)
+      end
+    end
+
+    # Access time of the most recently accessed SSH key.
+    #
+    # Needed to keep the default behavior backward compatible.
+    #
+    # @return [Time]
+    def keys_atime
+      keys.map(&:atime).max
+    end
+
+    # @return [Array<SshKey>]
+    def keys_to_export
+      keys.select(&:to_export?)
+    end
+
+    # @return [Array<SshConfigFile>]
+    def config_files_to_export
+      config_files.select(&:to_export?)
+    end
+
+  protected
+
+    def add_key(priv_filename)
+      key = SshKey.new(File.basename(priv_filename))
+      key.read_files(priv_filename)
+      self.keys << key
+    end
+
+    def add_config_file(filename)
+      file = SshConfigFile.new(File.basename(filename))
+      file.read(filename)
+      config_files << file
+    end
+  end
+end

src/lib/installation/ssh_config_file.rb

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+# 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 or 3 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.
+
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, contact SUSE LLC.
+
+#  To contact SUSE about this file by physical or electronic mail,
+#  you may find current contact information at www.suse.com
+
+require "fileutils"
+
+module Installation
+  # Class that allows to memorize a particular SSH config file found in a
+  # partition.
+  #
+  # Used by the SSH configuration importing functionality.
+  class SshConfigFile
+    BACKUP_SUFFIX = ".yast.orig"
+
+    # @return [String] file name
+    attr_accessor :name
+    # @return [Time] access time of the original file
+    attr_accessor :atime
+    # @return [String] content of the file
+    attr_accessor :content
+    # @return [Fixmum] mode of the original file. @see File.chmod
+    attr_accessor :permissions
+    # @return [Boolean] whether the file should be copied in the target system
+    attr_writer :to_export
+
+    def initialize(name)
+      @name = name
+      @to_export = false
+    end
+
+    def read(path)
+      self.content = IO.read(path)
+      self.atime = File.atime(path)
+      self.permissions = File.stat(path).mode
+    end
+
+    def write(dir)
+      path = File.join(dir, name)
+      backup(path)
+      IO.write(path, content)
+      File.chmod(permissions, path)
+    end
+
+    # @return [Boolean] whether the file should be copied in the target system
+    def to_export?
+      !!@to_export
+    end
+
+  protected
+
+    def backup(filename)
+      ::FileUtils.mv(filename, filename + BACKUP_SUFFIX) if File.exist?(filename)
+    end
+  end
+end

src/lib/installation/ssh_key.rb

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+# 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 or 3 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.
+
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, contact SUSE LLC.
+
+#  To contact SUSE about this file by physical or electronic mail,
+#  you may find current contact information at www.suse.com
+
+module Installation
+  # Class that allows to memorize a particular SSH keys found in a partition.
+  #
+  # Used to implement the SSH keys importing functionality.
+  class SshKey
+    PUBLIC_FILE_SUFFIX = ".pub"
+
+    # @return [String] name for the user to identify the key
+    attr_accessor :name
+    # @return [Time] access time of the most recently accessed file
+    attr_accessor :atime
+    # @return [Array<Keyfile>] list of files associated to the key
+    attr_accessor :files
+    # @return [Boolean] whether the key should be copied in the target system
+    attr_writer :to_export
+
+    def initialize(name)
+      @name = name
+      @files = []
+      @to_export = false
+    end
+
+    def read_files(priv_filename)
+      add_file(priv_filename) if File.exist?(priv_filename)
+      pub_filename = priv_filename + PUBLIC_FILE_SUFFIX
+      add_file(pub_filename) if File.exist?(pub_filename)
+    end
+
+    def write_files(dir)
+      files.each do |file|
+        path = File.join(dir, file.filename)
+        IO.write(path, file.content)
+        File.chmod(file.permissions, path)
+      end
+    end
+
+    # @return [Boolean] whether the key should be copied in the target system
+    def to_export?
+      !!@to_export
+    end
+
+  protected
+
+    KeyFile = Struct.new(:filename, :content, :permissions)
+
+    def add_file(path)
+      content = IO.read(path)
+      permissions = File.stat(path).mode
+      self.files << KeyFile.new(File.basename(path), content, permissions)
+      atime = File.atime(path)
+      self.atime = atime unless self.atime && self.atime > atime
+    end
+  end
+end

test/fixtures/root1/etc/os-release

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+PRETTY_NAME="Operating system 1"

test/fixtures/root1/etc/ssh/moduli

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+root1: content of moduli file

test/fixtures/root1/etc/ssh/ssh_config

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+root1: content of ssh_config file

test/fixtures/root1/etc/ssh/ssh_host_dsa_key

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+root1: content of ssh_host_dsa_key file

test/fixtures/root1/etc/ssh/ssh_host_dsa_key.pub

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+root1: content of ssh_host_dsa_key.pub file

test/fixtures/root1/etc/ssh/ssh_host_key

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+root1: content of ssh_host_key file

test/fixtures/root1/etc/ssh/ssh_host_key.pub

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+root1: content of ssh_host_key.pub file

test/fixtures/root1/etc/ssh/sshd_config

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+root1: content of sshd_config file

test/fixtures/root2/etc/ssh/known_hosts

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+root2: content of known_hosts file

test/fixtures/root2/etc/ssh/ssh_config

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+root2: content of ssh_config file

test/fixtures/root2/etc/ssh/ssh_host_ed25519_key

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+root2: content of ssh_host_ed25519_key file

test/fixtures/root2/etc/ssh/ssh_host_ed25519_key.pub

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+root2: content of ssh_host_ed25519_key.pub file

test/fixtures/root2/etc/ssh/ssh_host_key

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+root2: content of ssh_host_key file

test/fixtures/root2/etc/ssh/ssh_host_key.pub

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+root2: content of ssh_host_key.pub file

test/fixtures/root2/etc/ssh/sshd_config

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+root2: content of sshd_config file