add simple chrony object

src/lib/cfa/chrony_conf.rb

@@ -0,0 +1,76 @@
+require "cfa/base_model"
+require "cfa/augeas_parser"
+require "cfa/matcher"
+require "cfa/placer"
+
+module CFA
+  # class representings /etc/chrony.conf file model. It provides helper to manipulate
+  # with file. It uses CFA framework and Augeas parser.
+  # @see http://www.rubydoc.info/github/config-files-api/config_files_api/CFA/BaseModel
+  # @see http://www.rubydoc.info/github/config-files-api/config_files_api/CFA/AugeasParser
+  #
+  class ChronyConf < ::CFA::BaseModel
+    PATH = "/etc/chrony.conf".freeze
+
+    def initialize(file_handler: nil)
+      super(CFA::AugeasParser.new("chrony.lns"), PATH, file_handler: file_handler)
+    end
+
+    def load
+      super
+      fix_collection_names(data)
+    end
+
+    # options hash with key value, where value can be nil for keyword options
+    def add_pool(address, options)
+      # if there is already pool entry, place it after, if not, try use comment
+      existing_pools = pure_pools
+      if existing_pools.empty?
+        # for now first chrony have pools under comment mentioning pool.ntp.org
+        # so try to place it below
+        matcher = Matcher.new { |k,v| k.start_with?("#comment") && v =~ /www\.pool\.ntp\.org/ }
+      else
+        # place after the last pool available
+        matcher = Matcher.new(key: existing_pools.last[:key],
+          value_matcher: existing_pools.last[:value])
+      end
+      placer = AfterPlacer.new(matcher)
+
+      key = "pool[]"
+      value = AugeasTreeValue.new(AugeasTree.new, address)
+      options.each_pair do |k, v|
+        value.tree[k] = v
+      end
+
+      data.add(key, value, placer)
+    end
+
+    # delete all pools defined
+    def clear_pools
+      data.delete(POOLS_MATCHER)
+    end
+
+  private
+
+    COLLECTION_KEYS = [
+      "pool"
+    ]
+    # if there is only one element of collection, augeas does not add [],
+    # so fix it here for known keys which we modify ( and can be hitted with it )
+    def fix_collection_names(tree)
+      tree.data.each do |entry|
+        entry[:key] << "[]" if COLLECTION_KEYS.include?(entry[:key])
+        fix_collection_names(entry[:value].tree) if entry[:value].is_a?(AugeasTreeValue)
+        fix_collection_names(entry[:value]) if entry[:value].is_a?(AugeasTree)
+      end
+    end
+
+    POOLS_MATCHER = Matcher.new(collection: "pool")
+
+    # list of pools in internal data structure
+    def pure_pools
+      data.select(POOLS_MATCHER)
+    end
+
+  end
+end

test/cfa/chrony_conf_test.rb

@@ -0,0 +1,101 @@
+require_relative "../test_helper"
+require "cfa/memory_file"
+require "cfa/chrony_conf"
+
+def ntp_disk_content
+  path = File.expand_path("../../fixtures/cfa/chrony.conf.original", __FILE__)
+  File.read(path)
+end
+
+def ntp_file(content)
+  CFA::MemoryFile.new(content)
+end
+
+def ntp_conf(file)
+  CFA::ChronyConf.new(file_handler: file)
+end
+
+describe CFA::ChronyConf do
+  subject(:chrony) { ntp_conf(file) }
+
+  let(:file) { ntp_file(content) }
+
+  before do
+    subject.load
+  end
+
+  describe "#clear_pools" do
+    let(:content) do
+      "pool 2.opensuse.pool.ntp.org iburst\npool pool.ntp.org offline\n"
+    end
+
+    it "removes all pools from file" do
+      subject.clear_pools
+      subject.save
+      expect(file.content).to_not match(/pool/)
+    end
+  end
+
+  describe "#add_pool" do
+    context "there is already pool" do
+      let(:content) do
+        "# Use public servers from the pool.ntp.org project.\n"\
+        "# Please consider joining the pool (http://www.pool.ntp.org/join.html).\n" \
+        "pool 2.opensuse.pool.ntp.org iburst\n"\
+        "rtcsync\n"
+      end
+
+      let(:expected_output) do
+        "# Use public servers from the pool.ntp.org project.\n"\
+        "# Please consider joining the pool (http://www.pool.ntp.org/join.html).\n" \
+        "pool 2.opensuse.pool.ntp.org iburst\n"\
+        "pool ntp.suse.cz offline\n"\
+        "rtcsync\n"
+      end
+
+      it "adds new pool after the latest pool entry" do
+        subject.add_pool("ntp.suse.cz", "offline" => nil)
+        subject.save
+        expect(file.content).to eq expected_output
+      end
+    end
+
+    context "there is pool comments" do
+      let(:content) do
+        "# Use public servers from the pool.ntp.org project.\n"\
+        "# Please consider joining the pool (http://www.pool.ntp.org/join.html).\n" \
+        "rtcsync\n"
+      end
+
+      let(:expected_output) do
+        "# Use public servers from the pool.ntp.org project.\n"\
+        "# Please consider joining the pool (http://www.pool.ntp.org/join.html).\n" \
+        "pool ntp.suse.cz offline\n"\
+        "rtcsync\n"
+      end
+
+      it "adds new pool after the comment" do
+        subject.add_pool("ntp.suse.cz", "offline" => nil)
+        subject.save
+        expect(file.content).to eq expected_output
+      end
+    end
+
+    context "otherwise" do
+      let(:content) do
+        "rtcsync\n"
+      end
+
+      let(:expected_output) do
+        "rtcsync\n" \
+        "pool ntp.suse.cz offline\n"
+      end
+
+      it "adds new pool at the end" do
+        subject.add_pool("ntp.suse.cz", "offline" => nil)
+        subject.save
+        expect(file.content).to eq expected_output
+      end
+    end
+  end
+end

test/data/scr_root/etc/chrony.conf.original

@@ -0,0 +1,38 @@
+# Use public servers from the pool.ntp.org project.
+# Please consider joining the pool (http://www.pool.ntp.org/join.html).
+pool 2.opensuse.pool.ntp.org iburst
+
+# Record the rate at which the system clock gains/losses time.
+driftfile /var/lib/chrony/drift
+
+# Allow the system clock to be stepped in the first three updates
+# if its offset is larger than 1 second.
+makestep 1.0 3
+
+# Enable kernel synchronization of the real-time clock (RTC).
+rtcsync
+
+# Enable hardware timestamping on all interfaces that support it.
+#hwtimestamp *
+
+# Increase the minimum number of selectable sources required to adjust
+# the system clock.
+#minsources 2
+
+# Allow NTP client access from local network.
+#allow 192.168.0.0/16
+
+# Serve time even if not synchronized to a time source.
+#local stratum 10
+
+# Specify file containing keys for NTP authentication.
+#keyfile /etc/chrony.keys
+
+# Get TAI-UTC offset and leap seconds from the system tz database.
+#leapsectz right/UTC
+
+# Specify directory for log files.
+logdir /var/log/chrony
+
+# Select which information is logged.
+#log measurements statistics tracking