Add path.data functionality

But maintain reverse compatibility for older versions of Logstash

I don't yet know how to test this...

Fixes logstash-plugins#133

Author: untergeek

CHANGELOG.md

@@ -1,6 +1,7 @@
+## 3.1.0
+  - Use native `--path.data` for Logstash 5.0 for sincedb files.
 ## 3.0.3
   - Relax constraint on logstash-core-plugin-api to >= 1.60 <= 2.99
-
 ## 3.0.2
   - relax constrains of `logstash-devutils` see https://github.com/elastic/logstash-devutils/issues/48
 ## 3.0.1

CONTRIBUTORS

@@ -18,6 +18,7 @@ Contributors:
 * elliot moore (em295)
 * yjpa7145
 * Guy Boertje (guyboertje)
+* Aaron Mildenstein (untergeek)
 
 Note: If you've sent us patches, bug reports, or otherwise contributed to
 Logstash, and you aren't on the list above and want to be, please let us know

lib/logstash/inputs/file.rb

@@ -5,6 +5,7 @@
 
 require "pathname"
 require "socket" # for Socket.gethostname
+require "fileutils"
 
 # Stream events from files, normally by tailing them in a manner
 # similar to `tail -0F` but optionally reading them from the
@@ -170,6 +171,7 @@ def register
     require "digest/md5"
     @logger.info("Registering file input", :path => @path)
     @host = Socket.gethostname.force_encoding(Encoding::UTF_8)
+    @settings = defined?(LogStash::SETTINGS) ? LogStash::SETTINGS : nil
 
     @tail_config = {
       :exclude => @exclude,
@@ -189,6 +191,15 @@ def register
     end
 
     if @sincedb_path.nil?
+      if @settings
+        datapath = File.join(@settings.get_value("path.data"), "plugins", "inputs", "file")
+        # Ensure that the filepath exists before writing, since it's deeply nested.
+        FileUtils::mkdir_p datapath
+        @sincedb_path = File.join(datapath, ".sincedb_" + Digest::MD5.hexdigest(@path.join(",")))
+
+    # This section is going to be deprecated eventually, as path.data will be
+    # the default, not an environment variable (SINCEDB_DIR or HOME)
+    if @sincedb_path.nil? # If it is _still_ nil...
       if ENV["SINCEDB_DIR"].nil? && ENV["HOME"].nil?
         @logger.error("No SINCEDB_DIR or HOME environment variable set, I don't know where " \
                       "to keep track of the files I'm watching. Either set " \

logstash-input-file.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
   s.name            = 'logstash-input-file'
-  s.version         = '3.0.3'
+  s.version         = '3.1.0'
   s.licenses        = ['Apache License (2.0)']
   s.summary         = "Stream events from files."
   s.description     = "This gem is a Logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/logstash-plugin install gemname. This gem is not a stand-alone program"
@@ -32,4 +32,3 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'logstash-codec-json'
   s.add_development_dependency 'rspec-sequencing'
 end
-