Merge pull request #325 from github/jherns/auto-follow

Add auto Follow

Author: jherns

lib/elastomer_client/client/ccr.rb

@@ -36,6 +36,60 @@ def follow(follower_index, body, params = {})
         response = client.put "/#{follower_index}/_ccr/follow", params.merge(body:, action: "follow", rest_api: "ccr")
         response.body
       end
+
+      # Creates a new auto-follow pattern for the provided remote cluster.
+      #
+      # pattern_name - String name of the auto-follow pattern to create
+      # body         - Hash of the request body
+      #   :remote_cluster - String name of the remote cluster. Required.
+      #   :leader_index_patterns - An array of simple index patterns to match against indices in the remote cluster
+      #   :leader_index_exclusion_patterns - An array of simple index patterns that can be used to exclude indices from being auto-followed.
+      #   :follow_index_pattern - The name of follower index. The template {{leader_index}} can be used to derive
+      #                           the name of the follower index from the name of the leader index.
+      # params       - Hash of query parameters
+
+      # Examples
+
+      #   ccr.auto_follow("follower_pattern", { remote_cluster: "leader", leader_index_patterns: ["leader_index*"],
+      #                                         follow_index_pattern: "{{leader_index}}-follower" })
+
+      # See https://www.elastic.co/guide/en/elasticsearch/reference/current/ccr-put-auto-follow-pattern.html
+
+      def auto_follow(pattern_name, body, params = {})
+        response = client.put "/_ccr/auto_follow/#{pattern_name}", params.merge(body:, action: "create_auto_follow_pattern", rest_api: "ccr")
+        response.body
+      end
+
+      # Deletes the auto-follow pattern for the provided remote cluster.
+      #
+      # pattern_name - String name of the auto-follow pattern to delete
+      # params       - Hash of query parameters
+      #
+      # Examples
+      #
+      #   ccr.delete_auto_follow("follower_pattern")
+      #
+      # See https://www.elastic.co/guide/en/elasticsearch/reference/current/ccr-delete-auto-follow-pattern.html
+
+      def delete_auto_follow(pattern_name, params = {})
+        response = client.delete "/_ccr/auto_follow/#{pattern_name}", params.merge(action: "delete_auto_follow_pattern", rest_api: "ccr")
+        response.body
+      end
+
+      # Gets cross-cluster replication auto-follow patterns
+      #
+      # params - Hash of query parameters
+      #   :pattern_name - (Optional) String name of the auto-follow pattern. Returns all patterns if not specified
+      # Examples
+      #
+      #   ccr.get_auto_follow
+      #
+      # See https://www.elastic.co/guide/en/elasticsearch/reference/current/ccr-get-auto-follow-pattern.html
+
+      def get_auto_follow(params = {})
+        response = client.get "/_ccr/auto_follow{/pattern_name}", params.merge(action: "get_auto_follow_pattern", rest_api: "ccr")
+        response.body
+      end
     end
   end
 end

test/client/ccr_test.rb

@@ -8,22 +8,46 @@
 
     @leader_index = $client.index("leader_index")
     @follower_index = $replica_client.index("follower_index")
+    @auto_followed_index = $client.index("followed_index")
+    @auto_follower_index = $replica_client.index("followed_index-follower")
+
     if @leader_index.exists?
       @leader_index.delete
     end
+    if @auto_followed_index.exists?
+      @auto_followed_index.delete
+    end
     if @follower_index.exists?
       @follower_index.delete
     end
+    if @auto_follower_index.exists?
+      @auto_follower_index.delete
+    end
+
     @leader_index.create(default_index_settings)
     wait_for_index(@leader_index.name, "green")
 
     @leader_index.docs.index(document_wrapper("book", { _id: 1, title: "Book 1" }))
     @leader_index.refresh
+
+    begin
+      ccr.delete_auto_follow("follower_pattern")
+    rescue StandardError
+      puts "No auto-follow pattern to delete"
+    end
   end
 
   after do
     @leader_index.delete if @leader_index.exists?
     @follower_index.delete if @follower_index.exists?
+    @auto_followed_index.delete if @auto_followed_index.exists?
+    @auto_follower_index.delete if @auto_follower_index.exists?
+
+    begin
+      ccr.delete_auto_follow("follower_pattern")
+    rescue StandardError
+      puts "No auto-follow pattern to delete"
+    end
   end
 
   it "successfully follows a leader index" do
@@ -36,4 +60,22 @@
     assert_equal "Book 1", doc["_source"]["title"]
   end
 
+  it "successfully implements an auto-follow policy" do
+    ccr = $replica_client.ccr
+
+    ccr.auto_follow("follower_pattern", { remote_cluster: "leader", leader_index_patterns: ["*"], follow_index_pattern: "{{leader_index}}-follower" })
+
+    @auto_followed_index.create(default_index_settings)
+    wait_for_index(@auto_followed_index.name, "green")
+
+    @auto_follower_index = $replica_client.index("followed_index-follower")
+    wait_for_index(@auto_follower_index.name, "green")
+
+    resp = ccr.get_auto_follow(pattern_name: "follower_pattern")
+
+    assert_equal "follower_pattern", resp["patterns"].first["name"]
+
+    assert_predicate @auto_follower_index, :exists?
+  end
+
 end