Merge pull request #15 from azul/feature/replication

initial take on replication

3 files changed, 81 insertions, 0 deletions

diff --git a/lib/tapicero/replication.rb b/lib/tapicero/replication.rb
new file mode 100644
index 0000000..1a2db22
--- /dev/null
+++ b/lib/tapicero/replication.rb
@@ -0,0 +1,70 @@
+require 'couchrest'
+require 'json'
+
+module Tapicero
+  class Replication
+
+    LocalEndpoint = Struct.new(:name) do
+      def key; name; end
+      def url; name; end
+      def save_url; name; end
+    end
+
+    RemoteEndpoint = Struct.new(:remote, :credentials) do
+      def key;        domain; end
+      def url;       "http://#{creds}@#{domain}:#{port}/#{name}"; end
+      def save_url;  "http://#{username}@#{domain}:#{port}/#{name}"; end
+      def domain;    remote[:internal_domain]; end
+      def port;      remote[:couch_port]; end
+      def name;      remote[:name]; end
+      def creds;     username + ':' + credentials[:password]; end
+      def username;  credentials[:username]; end
+    end
+
+    def initialize(source, target)
+      @source = endpoint_for(source)
+      @target = endpoint_for(target)
+    end
+
+    def run(options)
+      Tapicero.logger.debug "Replicating from #{source.save_url} to #{target.save_url}."
+      replication_db.save_doc replication_doc.merge(options)
+    end
+
+    def replication_doc
+      {
+        _id: "#{source.key}_to_#{target.key}"
+        source: source.url,
+        target: target.url,
+        user_ctx: {
+          name: replication_credentials[:username],
+          roles: [replication_credentials[:role]]
+        }
+      }
+    end
+
+    protected
+
+    def endpoint_for(hash_or_string)
+      hash_or_string.respond_to? :[] ?
+        RemoteEndpoint.new(hash_or_string, replication_credentials) :
+        LocalEndpoint.new(hash_or_string)
+    end
+
+    def replication_credentials
+      config.options[:replication].slice(:username, :password, :role)
+    end
+
+    def replication_db
+      @replication_db ||= couch.database('_replicator')
+    end
+
+    def couch
+      @couch ||= CouchRest.new(config.couch_host)
+    end
+
+    def config
+      Tapicero.config
+    end
+
+end
diff --git a/lib/tapicero/user_database.rb b/lib/tapicero/user_database.rb
index f04e3e7..4061292 100644
--- a/lib/tapicero/user_database.rb
+++ b/lib/tapicero/user_database.rb
@@ -24,6 +24,16 @@ module Tapicero
       end
     end
 
+    def replicate()
+      return unless config.options[:mode] == 'mirror'
+      replication = config.options[:replication]
+      replication[:masters].each do |key, node|
+        retry_request_once "Replicating" do
+          Replication.new(source, name).run continuous: true
+        end
+      end
+    end
+
     def add_design_docs
       pattern = BASE_DIR + 'designs' + '*.json'
       Tapicero.logger.debug "Looking for design docs in #{pattern}"
diff --git a/lib/tapicero/user_event_handler.rb b/lib/tapicero/user_event_handler.rb
index 38cf8f8..e49416b 100644
--- a/lib/tapicero/user_event_handler.rb
+++ b/lib/tapicero/user_event_handler.rb
@@ -26,6 +26,7 @@ module Tapicero
       db.create
       db.secure
       db.add_design_docs
+      db.replicate
       logger.info "Prepared storage " + db.name
     end