diff --git a/.travis.yml b/.travis.yml
index ce66cd82e2..742dd54b60 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,6 +25,8 @@ matrix:
       dist: xenial
     - rvm: 2.6.5
       os: linux
+    - rvm: 2.7.0
+      os: linux
     - rvm: ruby-head
       os: linux
     - rvm: ruby-head
@@ -57,9 +59,6 @@ branches:
     - v0.12
     - v0.14
 
-before_install:
-  - gem update --system=2.7.8
-
 sudo: false
 dist: trusty # for TLSv1.2 support
 
diff --git a/fluentd.gemspec b/fluentd.gemspec
index 2263821ff2..52ec2f4aaf 100644
--- a/fluentd.gemspec
+++ b/fluentd.gemspec
@@ -40,7 +40,7 @@ Gem::Specification.new do |gem|
     gem.add_runtime_dependency("certstore_c", ["~> 0.1.2"])
   end
 
-  gem.add_development_dependency("rake", ["~> 11.0"])
+  gem.add_development_dependency("rake", ["~> 12.0"])
   gem.add_development_dependency("flexmock", ["~> 2.0"])
   gem.add_development_dependency("parallel_tests", ["~> 0.15.3"])
   gem.add_development_dependency("simplecov", ["~> 0.7"])
diff --git a/lib/fluent/config/literal_parser.rb b/lib/fluent/config/literal_parser.rb
index 3a798cb429..ce9307b3ce 100644
--- a/lib/fluent/config/literal_parser.rb
+++ b/lib/fluent/config/literal_parser.rb
@@ -19,7 +19,7 @@
 require 'json'
 require 'yajl'
 require 'socket'
-require 'irb/ruby-lex'  # RubyLex
+require 'ripper'
 
 require 'fluent/config/basic_parser'
 
@@ -155,15 +155,20 @@ def scan_nonquoted_string(boundary_charset = LINE_END)
       end
 
       def scan_embedded_code
-        rlex = RubyLex.new
-        src = '"#{'+@ss.rest+"\n=end\n}"
+        src = '"#{'+@ss.rest+"\n=begin\n=end\n}"
 
-        input = StringIO.new(src)
-        input.define_singleton_method(:encoding) { external_encoding }
-        rlex.set_input(input)
+        seek = -1
+        while (seek = src.index('}', seek + 1))
+          unless Ripper.sexp(src[0..seek] + '"').nil? # eager parsing until valid expression
+            break
+          end
+        end
+
+        unless seek
+          raise Fluent::ConfigParseError, @ss.rest
+        end
 
-        tk = rlex.token
-        code = src[3,tk.seek-3]
+        code = src[3, seek-3]
 
         if @ss.rest.length < code.length
           @ss.pos += @ss.rest.length
diff --git a/lib/fluent/plugin/out_http.rb b/lib/fluent/plugin/out_http.rb
index 4536fa3acd..8c225822ae 100644
--- a/lib/fluent/plugin/out_http.rb
+++ b/lib/fluent/plugin/out_http.rb
@@ -212,9 +212,9 @@ def send_request(uri, req)
             end
 
       if res.is_a?(Net::HTTPSuccess)
-        log.debug { "#{res.code} #{res.message}#{res.body}" }
+        log.debug { "#{res.code} #{res.message.rstrip}#{res.body.lstrip}" }
       else
-        msg = "#{res.code} #{res.message}#{res.body}"
+        msg = "#{res.code} #{res.message.rstrip} #{res.body.lstrip}"
 
         if @retryable_response_codes.include?(res.code.to_i)
           raise RetryableResponse, msg