Make release note from JIRA and Github

Makefile

@@ -305,4 +305,27 @@ sync-jira-components: $(addprefix create/jiracomponent/,$(subst lib/logstash/,,$
 	$(QUIET)rm tmp_jira_action_list
 
 create/jiracomponent/%: 
-	$(QUIET)echo "--action addComponent --project LOGSTASH --name $(subst create/jiracomponent/,,$@)" >> tmp_jira_action_list
+	$(QUIET)echo "--action addComponent --project LOGSTASH --name $(subst create/jiracomponent/,,$@)" >> tmp_jira_action_list
+
+## Release note section (up to you if/how/when to integrate in docs)
+# Collect the details of:
+#  - merged pull request from GitHub since last release
+#  - issues for FixVersion from JIRA
+
+# Note on used Github logic
+# We parse the commit between the last tag (should be the last release) and HEAD 
+# to extract all the notice about merged pull requests.
+
+# Note on used JIRA release note URL
+# The JIRA Release note list all issues (even open ones) 
+# with Fix Version assigned to target version
+# So one must verify manually that there is no open issue left (TODO use JIRACLI)
+
+# This is the ID for a version item in jira, can be obtained by CLI 
+# or through the Version URL https://logstash.jira.com/browse/LOGSTASH/fixforversion/xxx
+JIRA_VERSION_ID=10820
+
+releaseNote: 
+	-$(QUIET)rm releaseNote.html
+	$(QUIET)curl -si "https://logstash.jira.com/secure/ReleaseNote.jspa?version=$(JIRA_VERSION_ID)&projectId=10020" | sed -n '/<textarea.*>/,/<\/textarea>/p' | grep textarea -v >> releaseNote.html
+	$(QUIET)ruby pull_release_note.rb

pull_release_note.rb

@@ -0,0 +1,25 @@
+require "octokit"
+
+
+@repository= "logstash/logstash"
+@releaseNote= "releaseNote.html"
+
+#Last release  == last tag
+lastReleaseSha = Octokit.tags(@repository).first.commit.sha
+
+currentReleaseSha ="HEAD"
+
+#Collect PR Merge in a file
+File.open(@releaseNote, "a") do |f|
+  f.puts "<h2>Merged pull request</h2>"
+  f.puts "<ul>"
+  Octokit.compare(@repository, lastReleaseSha, currentReleaseSha).commits.each do |commit|
+    if commit.commit.message.start_with?("Merge pull")
+      scan_re = Regexp.new(/^Merge pull request #(\d+) from ([^\/]+)\/.*\n\n(.*)/)
+      commit.commit.message.scan(scan_re) do |pullNumber, user, summary|
+        f.puts "<li><a href='https://github.com/logstash/logstash/pull/#{pullNumber}'>Pull ##{pullNumber}<a> by #{user}: #{summary}</li>"
+      end
+    end
+  end
+  f.puts "</ul>"
+end