Add config_topic and spec

cosmos/lib/cosmos/topics/config_topic.rb

@@ -0,0 +1,68 @@
+# encoding: ascii-8bit
+
+# Copyright 2022 Ball Aerospace & Technologies Corp.
+# All Rights Reserved.
+#
+# This program is free software; you can modify and/or redistribute it
+# under the terms of the GNU Affero General Public License
+# as published by the Free Software Foundation; version 3 with
+# attribution addendums as found in the LICENSE.txt
+#
+# 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 Affero General Public License for more details.
+#
+# This program may also be used under the terms of a commercial or
+# enterprise edition license of COSMOS if purchased from the
+# copyright holder
+
+require 'cosmos/topics/topic'
+
+module Cosmos
+  class ConfigTopic < Topic
+    PRIMARY_KEY = "__CONFIG"
+
+    # Helper method to initialize the stream and ensure a consistent key
+    def self.initialize_stream(scope)
+      self.initialize_streams(["#{scope}#{PRIMARY_KEY}"])
+    end
+
+    # Write a configuration change to the topic
+    # @param config [Hash] Hash with required keys 'kind', 'name', 'type'
+    def self.write(config, scope:)
+      unless config.keys.include?(:kind)
+        raise "ConfigTopic error, required key kind: not given"
+      end
+      unless ['created', 'deleted'].include?(config[:kind])
+        raise "ConfigTopic error unknown kind: #{config[:kind]}"
+      end
+      unless config.keys.include?(:name)
+        raise "ConfigTopic error, required key name: not given"
+      end
+      unless config.keys.include?(:type)
+        raise "ConfigTopic error, required key type: not given"
+      end
+      # Limit the configuration topics to 1000 entries
+      Topic.write_topic("#{scope}#{PRIMARY_KEY}", config, '*', 1000)
+    end
+
+    def self.read(offset = nil, count: 100, scope:)
+      topic = "#{scope}#{PRIMARY_KEY}"
+      if offset
+        result = Topic.read_topics([topic], [offset], nil, count)
+        if result.empty?
+          [] # We want to return an empty array rather than an empty hash
+        else
+          # result is a hash with the topic key followed by an array of results
+          # This returns just the array of arrays [[offset, hash], [offset, hash], ...]
+          result[topic]
+        end
+      else
+        result = Topic.get_newest_message(topic)
+        return [result] if result
+        return []
+      end
+    end
+  end
+end

cosmos/spec/topics/config_topic_spec.rb

@@ -0,0 +1,76 @@
+# encoding: ascii-8bit
+
+# Copyright 2022 Ball Aerospace & Technologies Corp.
+# All Rights Reserved.
+#
+# This program is free software; you can modify and/or redistribute it
+# under the terms of the GNU Affero General Public License
+# as published by the Free Software Foundation; version 3 with
+# attribution addendums as found in the LICENSE.txt
+#
+# 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 Affero General Public License for more details.
+#
+# This program may also be used under the terms of a commercial or
+# enterprise edition license of COSMOS if purchased from the
+# copyright holder
+
+require 'spec_helper'
+require 'cosmos/topics/config_topic'
+
+module Cosmos
+  describe ConfigTopic do
+    before(:each) do
+      mock_redis()
+    end
+
+    describe "self.initialize_stream" do
+      it "initializes the stream with the scope" do
+        ConfigTopic.initialize_stream('DEFAULT')
+        expect(EphemeralStore.scan_each(type: 'stream', count: 100).to_a).to include("DEFAULT__CONFIG")
+      end
+    end
+
+    describe "self.write" do
+      it "requires kind, type, name keys" do
+        expect { ConfigTopic.write({ type: 'target', name: 'INST', plugin: 'PLUGIN'}, scope: 'DEFAULT') }.to raise_error(/ConfigTopic error/)
+        expect { ConfigTopic.write({ kind: 'created', name: 'INST', plugin: 'PLUGIN'}, scope: 'DEFAULT') }.to raise_error(/ConfigTopic error/)
+        expect { ConfigTopic.write({ kind: 'created', type: 'target', plugin: 'PLUGIN'}, scope: 'DEFAULT') }.to raise_error(/ConfigTopic error/)
+      end
+
+      it "requires kind to be 'created' or 'deleted'" do
+        expect { ConfigTopic.write({ kind: 'unknown', type: 'target', name: 'INST', plugin: 'PLUGIN'}, scope: 'DEFAULT') }.to raise_error(/ConfigTopic error/)
+      end
+    end
+
+    describe "self.read" do
+      it "reads from an offset" do
+        ConfigTopic.initialize_stream('DEFAULT')
+        ConfigTopic.write({ kind: 'created', type: 'target', name: 'INST', plugin: 'PLUGIN'}, scope: 'DEFAULT')
+        ConfigTopic.write({ kind: 'deleted', type: 'target', name: 'INST', plugin: 'PLUGIN'}, scope: 'DEFAULT')
+        config = ConfigTopic.read(0, scope: 'DEFAULT') # read all
+        expect(config[0][1]['kind']).to eql 'created'
+        expect(config[0][1]['type']).to eql 'target'
+        expect(config[0][1]['name']).to eql 'INST'
+        expect(config[0][1]['plugin']).to eql 'PLUGIN'
+        expect(config[1][1]['kind']).to eql 'deleted'
+        expect(config[1][1]['type']).to eql 'target'
+        expect(config[1][1]['name']).to eql 'INST'
+        expect(config[1][1]['plugin']).to eql 'PLUGIN'
+      end
+
+      it "reads the latest" do
+        ConfigTopic.initialize_stream('DEFAULT')
+        ConfigTopic.write({ kind: 'created', type: 'target', name: 'INST', plugin: 'PLUGIN'}, scope: 'DEFAULT')
+        ConfigTopic.write({ kind: 'deleted', type: 'target', name: 'INST', plugin: 'PLUGIN'}, scope: 'DEFAULT')
+        config = ConfigTopic.read(scope: 'DEFAULT') # read latest
+        expect(config[0][1]['kind']).to eql 'deleted'
+        expect(config[0][1]['type']).to eql 'target'
+        expect(config[0][1]['name']).to eql 'INST'
+        expect(config[0][1]['plugin']).to eql 'PLUGIN'
+      end
+    end
+  end
+end