logstash code refactor and doc improvements (#2410)

* logstash code refactor and doc improvements

* added back gradlew assemble

cmd/logstash/README.md

@@ -1,10 +1,12 @@
 # Contributing to Loki Logstash Output Plugin
 
-For information about hwo to use this plugin see this [documentation](../../docs/clients/logstash/README.md).
+For information about how to use this plugin see this [documentation](../../docs/sources/clients/logstash/_index.md).
 
 ## Install dependencies
 
-First you need to setup JRuby environment to build this plugin. Refer https://github.com/rbenv/rbenv for setting up your rbenv environment.
+First, make sure you have JDK version `8` or `11` installed and you have set the `JAVA_HOME` environment variable.
+
+You need to setup JRuby environment to build this plugin. Refer https://github.com/rbenv/rbenv for setting up your rbenv environment.
 
 After setting up `rbenv`. Install JRuby
 
@@ -20,7 +22,7 @@ ruby --version
 jruby 9.2.10
 ```
 
-You should use make sure you are running jruby and not ruby. If the command below still shows ruby and not jruby, check that PATH contains `$HOME/.rbenv/shims` and `$HOME/.rbenv/bin`. Also verify that you have this in your bash profile:
+You should make sure you are running `jruby` and not `ruby`. If the command `ruby --version` still shows `ruby` and not `jruby`, check that PATH contains `$HOME/.rbenv/shims` and `$HOME/.rbenv/bin`. Also verify that you have this in your bash profile:
 
 ```bash
 export PATH="$HOME/.rbenv/bin:$PATH"
@@ -32,7 +34,7 @@ Then install bundler
 
 Follow those instructions to [install logstash](https://www.elastic.co/guide/en/logstash/current/installing-logstash.html) before moving to the next section.
 
-## Install dependencies and Build plugin
+## Build and test the plugin
 
 ### Install required packages
 

cmd/logstash/lib/logstash/outputs/loki.rb

@@ -30,6 +30,9 @@ class LogStash::Outputs::Loki < LogStash::Outputs::Base
   ## 'TLS'
   config :ca_cert, :validate => :path, :required => false
 
+  ## 'Disable server certificate verification'
+  config :insecure_skip_verify, :validate => :boolean, :default => false, :required => false
+
   ## 'Loki Tenant ID'
   config :tenant_id, :validate => :string, :required => false
 
@@ -45,8 +48,8 @@ class LogStash::Outputs::Loki < LogStash::Outputs::Base
   ## 'Backoff configuration. Initial backoff time between retries. Default 1s'
   config :min_delay, :validate => :number, :default => 1, :required => false
 
-   ## 'Backoff configuration. Maximum backoff time between retries. Default 300s'
-   config :max_delay, :validate => :number, :default => 300, :required => false
+  ## 'Backoff configuration. Maximum backoff time between retries. Default 300s'
+  config :max_delay, :validate => :number, :default => 300, :required => false
 
   ## 'Backoff configuration. Maximum number of retries to do'
   config :retries, :validate => :number, :default => 10, :required => false
@@ -102,6 +105,13 @@ def ssl_opts(uri)
       use_ssl: uri.scheme == 'https'
     }
 
+     # disable server certificate verification
+    if @insecure_skip_verify
+      opts = opts.merge(
+        verify_mode: OpenSSL::SSL::VERIFY_NONE
+      )
+    end
+
     if !@cert.nil? && !@key.nil?
       opts = opts.merge(
         verify_mode: OpenSSL::SSL::VERIFY_PEER,
@@ -119,7 +129,8 @@ def ssl_opts(uri)
   end
 
   def run()
-	  min_wait_checkfrequency = 1/100 #1 millisecond
+    # minimum wait frequency is 1 millisecond
+	  min_wait_checkfrequency = 1/100 
 	  max_wait_checkfrequency = @batch_wait / 10
 	  if max_wait_checkfrequency < min_wait_checkfrequency
 		  max_wait_checkfrequency = min_wait_checkfrequency
@@ -139,7 +150,7 @@ def run()
          end
         }
         s.take(@max_wait_check) {
-          # Send batch if max wait time has been reached
+          # send batch if max wait time has been reached
           if is_batch_expired
             @logger.debug("Max batch_wait time is reached. Sending batch to loki")
             send(@batch)
@@ -150,7 +161,7 @@ def run()
     end
   end
 
-  # add an entry to the current batch return false if the batch is full
+  # Add an entry to the current batch returns false if the batch is full
   # and the entry can't be added.
   def add_entry_to_batch(e)
     line = e.entry['line']
@@ -222,13 +233,13 @@ def loki_http_request(payload)
       raise StandardError.new res
     rescue StandardError => e
       retry_count += 1
-      @logger.warn("Failed to send batch attempt: #{retry_count}/#{@retries}", :error_inspect => e.inspect, :error => e)
+      @logger.warn("Failed to send batch, attempt: #{retry_count}/#{@retries}", :error_inspect => e.inspect, :error => e)
       if retry_count < @retries
         sleep delay
-        if (delay * 2 - delay) > @max_delay
-          delay = delay
-        else
+        if delay * 2 <= @max_delay
           delay = delay * 2
+        else
+          delay = @max_delay
         end
         retry
       else

cmd/logstash/logstash-output-loki.gemspec

@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
-  s.name = 'logstash-output-loki'
-  s.version         = '1.0.1'
+  s.name    = 'logstash-output-loki'
+  s.version = '1.0.2'
   s.authors = ['Aditya C S','Cyril Tovena']
   s.email   = ['aditya.gnu@gmail.com','cyril.tovena@grafana.com']
 

cmd/logstash/loki.conf

@@ -33,5 +33,7 @@ output {
     # key => /path/to/key.key
 
     # ca_cert => /path/to/ca.pem
+
+    # insecure_skip_verify => false
   }
 }

docs/sources/clients/logstash/_index.md

@@ -74,6 +74,7 @@ output {
 
     [ca_cert => path | default = nil | required=false]
 
+    [insecure_skip_verify => boolean | default = fasle | required=false]
   }
 }
 ```
@@ -229,6 +230,10 @@ Loki is a multi-tenant log storage platform and all requests sent must include a
 
 Specify a pair of client certificate and private key with `cert` and `key` if a reverse proxy with client certificate verification is configured in front of Loki. `ca_cert` can also be specified if the server uses custom certificate authority.
 
+### insecure_skip_verify
+
+A flag to disable server certificate verification. By default it is set to `false`.
+
 ### Full configuration example
 
 ```conf