From 8c5f87c9d4118849bc2783db59997322b4064318 Mon Sep 17 00:00:00 2001
From: Thorsten Eckel <te@znuny.com>
Date: Thu, 8 Mar 2018 16:30:07 +0100
Subject: [PATCH] Humanized error messages created by failing elasticsearch
 requests.

---
 lib/search_index_backend.rb | 80 ++++++++++++++++++++++++++++++++-----
 1 file changed, 71 insertions(+), 9 deletions(-)

diff --git a/lib/search_index_backend.rb b/lib/search_index_backend.rb
index b12a5ee74..147bbce75 100644
--- a/lib/search_index_backend.rb
+++ b/lib/search_index_backend.rb
@@ -26,8 +26,13 @@ info about used search index machine
       }
     )
     Rails.logger.info "# #{response.code}"
-    raise "Unable to process GET at #{url}\n#{response.inspect}" if !response.success?
-    response.data
+    return response.data if response.success?
+
+    raise humanized_error(
+      verb:     'GET',
+      url:      url,
+      response: response,
+    )
   end
 
 =begin
@@ -75,7 +80,12 @@ update processors
           Rails.logger.info "# #{response.code}"
           next if response.success?
           next if response.code.to_s == '404'
-          raise "Unable to process DELETE at #{url}\n#{response.inspect}"
+
+          raise humanized_error(
+            verb:     'DELETE',
+            url:      url,
+            response: response,
+          )
         end
         Rails.logger.info "# curl -X PUT \"#{url}\" \\"
         Rails.logger.debug "-d '#{data.to_json}'"
@@ -93,7 +103,13 @@ update processors
         )
         Rails.logger.info "# #{response.code}"
         next if response.success?
-        raise "Unable to process PUT at #{url}\n#{response.inspect}"
+
+        raise humanized_error(
+          verb:     'PUT',
+          url:      url,
+          payload:  item,
+          response: response,
+        )
       end
     end
     true
@@ -156,7 +172,13 @@ create/update/delete index
     )
     Rails.logger.info "# #{response.code}"
     return true if response.success?
-    raise "Unable to process PUT at #{url}\n#{response.inspect}"
+
+    raise humanized_error(
+      verb:     'PUT',
+      url:      url,
+      payload:  data[:data],
+      response: response,
+    )
   end
 
 =begin
@@ -188,7 +210,13 @@ add new object to search index
     )
     Rails.logger.info "# #{response.code}"
     return true if response.success?
-    raise "Unable to process POST at #{url} (size: #{data.to_json.bytesize / 1024 / 1024}M)\n#{response.inspect}"
+
+    raise humanized_error(
+      verb:     'POST',
+      url:      url,
+      payload:  data,
+      response: response,
+    )
   end
 
 =begin
@@ -219,7 +247,13 @@ remove whole data from index
     Rails.logger.info "# #{response.code}"
     return true if response.success?
     return true if response.code.to_s == '400'
-    Rails.logger.info "NOTICE: can't delete index #{url}: " + response.inspect
+
+    humanized_error = humanized_error(
+      verb:     'DELETE',
+      url:      url,
+      response: response,
+    )
+    Rails.logger.info "NOTICE: can't delete index: #{humanized_error}"
     false
   end
 
@@ -326,7 +360,12 @@ return search result
 
     Rails.logger.info "# #{response.code}"
     if !response.success?
-      Rails.logger.error "ERROR: POST on #{url}\n#{response.inspect}"
+      Rails.logger.error humanized_error(
+        verb:     'GET',
+        url:      url,
+        payload:  data,
+        response: response,
+      )
       return []
     end
     data = response.data
@@ -419,7 +458,12 @@ get count of tickets and tickets which match on selector
 
     Rails.logger.info "# #{response.code}"
     if !response.success?
-      raise "Unable to process POST at #{url}\n#{response.inspect}"
+      raise humanized_error(
+        verb:     'GET',
+        url:      url,
+        payload:  data,
+        response: response,
+      )
     end
     Rails.logger.debug response.data.to_json
 
@@ -546,4 +590,22 @@ return true if backend is configured
     url
   end
 
+  def self.humanized_error(verb:, url:, payload: nil, response:)
+    prefix = "Unable to process #{verb} request to elasticsearch URL '#{url}'."
+    suffix = "\n\nResponse:\n#{response.inspect}\n\nPayload:\n#{payload.inspect}"
+
+    if payload.respond_to?(:to_json)
+      suffix += "\n\nPayload size: #{payload.to_json.bytesize / 1024 / 1024}M"
+    end
+
+    message = if response&.error&.match?('Connection refused')
+                "Elasticsearch is not reachable, probably because it's not running or even installed."
+              elsif url.end_with?('pipeline/zammad-attachment') && response.code == 400
+                'The installed attachment plugin could not handle the request payload. Ensure that the correct attachment plugin is installed (5.6 => ingest-attachment, 2.4 - 5.5 => mapper-attachments).'
+              else
+                'Check the response and payload for detailed information: '
+              end
+
+    "#{prefix}#{message}#{suffix}"
+  end
 end