ensure that solr checksum verification does not obscure 404 responses…

… or tcp/http errors

backend/app/main.rb

@@ -149,7 +149,7 @@ def self.plugins_loaded_hook(&block)
         Solr.verify_checksums!
         Log.info('Solr config checksum verification ok.')
       else
-        Log.warn('Solr config checksum verification disabled.')
+        Log.warn('Solr config checksum verification disabled: Solr may be offline or misconfigured')
       end
 
       ordered_plugin_backend_dirs = ASUtils.order_plugins(ASUtils.find_local_directories('backend'))

backend/app/model/solr.rb

@@ -3,6 +3,10 @@
 require 'advanced_search'
 
 class Solr
+
+  class ChecksumMismatchError < StandardError; end
+  class NotFound < StandardError; end
+
   module Checksums
     def checksum_valid?
       internal_checksum == external_checksum
@@ -20,7 +24,19 @@ def internal_checksum
 
     def lookup_external_checksum
       url = URI(File.join(@url, @path))
-      @external_checksum = Digest::SHA2.hexdigest(Net::HTTP.get_response(url).body)
+      response = Net::HTTP.get_response(url)
+      if response.code == '200'
+        @external_checksum = Digest::SHA2.hexdigest(response.body)
+      else
+        # if we made it this far, solr (or another server) is probably there
+        # but cannot find the documents we want, most likely because the core
+        # has not been set up correctly.
+        message = "Status #{response.code} when trying to verify #{@url}"
+        if response.body
+          message += "Server response:\n#{response.body}"
+        end
+        raise NotFound.new(message)
+      end
     end
 
     def lookup_internal_checksum
@@ -76,7 +92,7 @@ def self.verify_checksums!
   def self.verify_checksum!(config)
     return true if config.checksum_valid?
 
-    raise "Solr checksum verification failed (#{config.name}): expected [#{config.internal_checksum}] got [#{config.external_checksum}]"
+    raise ChecksumMismatchError.new "Solr checksum verification failed (#{config.name}): expected [#{config.internal_checksum}] got [#{config.external_checksum}]"
   end
 
   class Query

backend/spec/model_solr_spec.rb

@@ -210,28 +210,40 @@ def response.code; '200'; end
   end
 
   describe 'Checksums' do
-    let(:schema) { Solr::Schema.new(AppConfig[:solr_url]) }
-    let(:solrconfig) { Solr::Solrconfig.new(AppConfig[:solr_url]) }
+    let(:response) { instance_double(Net::HTTPResponse) }
 
-    it 'will be valid when the internal and external checksums match' do
-      expect(schema.checksum_valid?).to be true
-      expect(solrconfig.checksum_valid?).to be true
+    def solrfile(file)
+      File.read(File.join(*[ ASUtils.find_base_directory, 'solr', file]))
     end
 
-    it 'will be invalid when the external checksums do not match' do
-      allow(schema).to receive(:external_checksum) { 'nope' }
-      allow(solrconfig).to receive(:external_checksum) { "this_aint'it" }
+    it 'will be valid when the internal and external checksums match' do
+      allow(response).to receive(:code).and_return('200')
+      allow(response).to receive(:body).and_return(solrfile('schema.xml'), solrfile('solrconfig.xml'))
+      allow(Net::HTTP).to receive(:get_response).and_return(response)
+      expect { Solr.verify_checksums! }.not_to raise_error
+    end
 
-      expect(schema.checksum_valid?).to be false
-      expect(solrconfig.checksum_valid?).to be false
+    it 'will be invalid when the schema checksum does not match' do
+      allow(response).to receive(:code).and_return('200')
+      bad_schema = solrfile('schema.xml').sub('archivesspace', 'example')
+      allow(response).to receive(:body).and_return(bad_schema, solrfile('solrconfig.xml'))
+      allow(Net::HTTP).to receive(:get_response).and_return(response)
+      expect { Solr.verify_checksums! }.to raise_error(Solr::ChecksumMismatchError)
     end
 
-    it 'will be invalid when the internal checksums do not match' do
-      allow(schema).to receive(:internal_checksum) { 'nope' }
-      allow(solrconfig).to receive(:internal_checksum) { "this_aint'it" }
+    it 'will be invalid when the config checksum does not match' do
+      allow(response).to receive(:code).and_return('200')
+      bad_config = solrfile('solrconfig.xml').sub('solr', 'foobar')
+      allow(response).to receive(:body).and_return(solrfile('schema.xml'), bad_config)
+      allow(Net::HTTP).to receive(:get_response).and_return(response)
+      expect { Solr.verify_checksums! }.to raise_error(Solr::ChecksumMismatchError)
+    end
 
-      expect(schema.checksum_valid?).to be false
-      expect(solrconfig.checksum_valid?).to be false
+    it 'will raise an error when the solr server returns a 404' do
+      allow(response).to receive(:code).and_return('404')
+      allow(response).to receive(:body).and_return("NOT FOUND")
+      allow(Net::HTTP).to receive(:get_response).and_return(response)
+      expect { Solr.verify_checksums! }.to raise_error(Solr::NotFound)
     end
   end