remove sqlite from supported database adapters

Dockerfile

@@ -43,7 +43,7 @@ RUN umask 002 && git init && \
 
 COPY . .
 
-ENV LC_ALL=en_US.UTF-8 RAILS_ENV=production DATABASE_URL=sqlite3:/data/huginn.db
+ENV LC_ALL=en_US.UTF-8 RAILS_ENV=production DATABASE_URL=postgres://localhost
 
 RUN bundle exec rails assets:precompile && rm -rf app/assets spec
 
@@ -58,7 +58,7 @@ RUN addgroup -g 1000 -S app \
 
 RUN apk --update add --no-cache \
   git zlib yaml libssl3 gdbm readline ncurses-libs libffi libxml2 libxslt icu \
-  sqlite-libs mariadb-connector-c libpq \
+  mariadb-connector-c libpq \
   graphviz curl tzdata shared-mime-info iputils jq \
   libc6-compat nodejs && \
   mkdir /data && \
@@ -74,7 +74,7 @@ ENV LC_ALL=en_US.UTF-8 \
   RAILS_LOG_TO_STDOUT=true \
   RAILS_SERVE_STATIC_FILES=true \
   IP="0.0.0.0" PORT=3000 \
-  DATABASE_URL=sqlite3:/data/huginn.db \
+  DATABASE_URL=postgres://localhost \
   APP_SECRET_TOKEN=changeme 
 
 USER app

config/environments/production.rb

@@ -100,8 +100,4 @@
   config.action_mailer.delivery_method = ENV.fetch('SMTP_DELIVERY_METHOD', 'smtp').to_sym
   config.action_mailer.perform_caching = false
   # smtp_settings moved to config/initializers/action_mailer.rb
-
-  if ENV['DATABASE_URL'].start_with? "sqlite"
-    config.middleware.use ConnectionManagement
-  end
 end

lib/rdbms_functions.rb

@@ -6,8 +6,6 @@ def rdbms_date_add(source, unit, amount)
         "DATE_ADD(`#{source}`, INTERVAL #{amount} #{unit})"
       when :postgresql
         "(#{source} + INTERVAL '#{amount} #{unit}')"
-      when :sqlite
-        "datetime('#{source}', '+ #{amount} #{unit}')"
       else
         raise NotImplementedError, "Unknown adapter type '#{adapter_type}'"
     end