Update elasticsearch

- Build our own elasticsearch image based on 6.8.6 which includes
configuration files for german decompounder from https://github.com/uschindler/german-decompounder

- move elastichq to separate service and use the official image instead of including it as plugin in the elasticsearch image

- Adjust compounder filter config in papers to use the included hyphenation_decompounder.
See https://www.elastic.co/guide/en/elasticsearch/reference/6.8/analysis-compound-word-tokenfilter.html

- Remove obsolete "string" type in the mapping of papers, and replace it
with "text" or "keywords" accordingly. See https://www.elastic.co/blog/strings-are-dead-long-live-strings

Gemfile

@@ -31,8 +31,8 @@ gem 'omniauth'
 gem 'omniauth-browserid'
 
 gem 'elasticsearch', '~> 6'
-gem 'elasticsearch-model'
-gem 'elasticsearch-rails'
+gem 'elasticsearch-model', '~> 6'
+gem 'elasticsearch-rails', '~> 6'
 gem 'elasticsearch-dsl'
 
 gem 'leaflet-rails'

Gemfile.lock

@@ -79,11 +79,11 @@ GEM
     elasticsearch-api (6.0.2)
       multi_json
     elasticsearch-dsl (0.1.5)
-    elasticsearch-model (5.0.0)
+    elasticsearch-model (6.1.0)
       activesupport (> 3)
       elasticsearch (> 1)
       hashie
-    elasticsearch-rails (5.0.2)
+    elasticsearch-rails (6.1.0)
     elasticsearch-transport (6.0.2)
       faraday
       multi_json
@@ -287,8 +287,8 @@ DEPENDENCIES
   database_cleaner
   elasticsearch (~> 6)
   elasticsearch-dsl
-  elasticsearch-model
-  elasticsearch-rails
+  elasticsearch-model (~> 6)
+  elasticsearch-rails (~> 6)
   factory_bot_rails
   faker
   foundation-rails (~> 5.5)

app/models/paper.rb

@@ -33,9 +33,13 @@ class Paper < ActiveRecord::Base
           type: "stemmer",
           language: "light_german"
         },
-		  decomp: {
-		    type: "decompound"
-          }
+        german_decompounder: {
+          type: "hyphenation_decompounder",
+          word_list_path: "analysis/dictionary-de.txt",
+          hyphenation_patterns_path: "analysis/de_DR.xml",
+          only_longest_match: true,
+          min_subword_size: 4
+        },
       },
       analyzer: {
         german: {
@@ -43,21 +47,21 @@ class Paper < ActiveRecord::Base
           filter: [
             "lowercase",
             "german_stop",
+              "german_decompounder",
             "german_normalization",
-		      "german_stemmer",
-		      "decomp"
+            "german_stemmer"
           ]
         }
       }
     }
     } do mappings dynamic: false do
-      indexes :name, type: :string, analyzer: "german"
-      indexes :content, type: :string, analyzer: "german"
-      indexes :resolution, type: :string, analyzer: "german"
-      indexes :reference, type: :string, index: :not_analyzed
-      indexes :paper_type, type: :string, index: :not_analyzed
-      indexes :published_at, type: :date, index: :not_analyzed
-      indexes :originator, type: :string, index: :not_analyzed
+      indexes :name, type: :text, analyzer: "german"
+      indexes :content, type: :text, analyzer: "german"
+      indexes :resolution, type: :text, analyzer: "german"
+      indexes :reference, type: :keyword, index: true
+      indexes :paper_type, type: :keyword, index: true
+      indexes :published_at, type: :date, index: true
+      indexes :originator, type: :keyword, index: true
     end
   end
 

docker-compose.yml

@@ -1,4 +1,8 @@
-web:
+version: "3.7"
+volumes:
+  elasticsearch:
+services:
+  web:
     build: .
     volumes:
       - .:/app
@@ -8,15 +12,17 @@ web:
       - elasticsearch
     environment:
       ELASTICSEARCH_URL: 'http://elasticsearch:9200'
-elasticsearch:
-  image: elasticsearch:5.4.3
-  command:
-    - sh
-    - -c
-    - "./bin/elasticsearch-plugin install http://xbib.org/repository/org/xbib/elasticsearch/plugin/elasticsearch-analysis-decompound/5.4.3.0/elasticsearch-analysis-decompound-5.4.3.0-plugin.zip;
-      ./bin/elasticsearch-plugin install https://github.com/royrusso/elasticsearch-HQ/zipball/master;
-       /docker-entrypoint.sh elasticsearch"
+  elasticsearch:
+    build: ./docker/elasticsearch
+    environment:
+      - discovery.type=single-node
     ports:
       - "9200:9200"
     volumes:
-    - .:/apps
+      - elasticsearch:/usr/share/elasticsearch/data
+  elastichq:
+    image: elastichq/elasticsearch-hq
+    ports:
+      - "5000:5000"
+    links:
+      - elasticsearch

docker/elasticsearch/Dockerfile

@@ -0,0 +1,8 @@
+FROM elasticsearch:6.8.6
+
+RUN \
+  mkdir -p /usr/share/elasticsearch/config/analysis && \
+  pushd /usr/share/elasticsearch/config/analysis && \
+  curl -sSLO https://github.com/uschindler/german-decompounder/raw/master/de_DR.xml && \
+  curl -sSLO https://github.com/uschindler/german-decompounder/raw/master/dictionary-de.txt && \
+  popd