Class: LogStash::Outputs::Loki

Inherits:
Base
  • Object
show all
Includes:
Loki
Defined in:
lib/logstash/outputs/loki.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Loki

#to_ns

Instance Attribute Details

#batch ⇒ Object (readonly)

Returns the value of attribute batch.



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# File 'lib/logstash/outputs/loki.rb', line 60

def batch
  @batch
end

Instance Method Details

#add_entry_to_batch(e) ⇒ Object

Add an entry to the current batch returns false if the batch is full and the entry can’t be added.



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# File 'lib/logstash/outputs/loki.rb', line 181

def add_entry_to_batch(e)
  line = e.entry['line']
  # we don't want to send empty lines.
  return true if line.to_s.strip.empty?

  if @batch.nil?
    @batch = Batch.new(e)
    return true
  end

  if @batch.size_bytes_after(line) > @batch_size
    return false
  end
  @batch.add(e)
  return true
end

#batch_size ⇒ Object

‘Maximum batch size to accrue before pushing to loki. Defaults to 102400 bytes’



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# File 'lib/logstash/outputs/loki.rb', line 40

config :batch_size, :validate => :number, :default => 102400, :required => false

#batch_wait ⇒ Object

‘Interval in seconds to wait before pushing a batch of records to loki. Defaults to 1 second’



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# File 'lib/logstash/outputs/loki.rb', line 43

config :batch_wait, :validate => :number, :default => 1, :required => false

#ca_cert ⇒ Object

‘TLS’



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# File 'lib/logstash/outputs/loki.rb', line 31

config :ca_cert, :validate => :path, :required => false

#cert ⇒ Object

‘Client certificate’



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# File 'lib/logstash/outputs/loki.rb', line 27

config :cert, :validate => :path, :required => false

#close ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 208

def close
  @entries.close
  @mutex.synchronize do 
    @stop = true 
  end
  @batch_wait_thread.join
  @batch_size_thread.join

  # if by any chance we still have a forming batch, we need to send it.
  send(@batch) if !@batch.nil?
  @batch = nil
end

#gzip(data) ⇒ Object

gzip data



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# File 'lib/logstash/outputs/loki.rb', line 221

def gzip(data)
  gz = StringIO.new
  gz.set_encoding("BINARY")
  z = Zlib::GzipWriter.new(gz)
  z.write(data)
  z.close
  gz.string
end

#include_fields ⇒ Object

‘An array of fields to map to labels, if defined only fields in this list will be mapped.’



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# File 'lib/logstash/outputs/loki.rb', line 52

config :include_fields, :validate => :array, :default => [], :required => false

#insecure_skip_verify ⇒ Object

‘Disable server certificate verification’



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# File 'lib/logstash/outputs/loki.rb', line 34

config :insecure_skip_verify, :validate => :boolean, :default => false, :required => false

#is_batch_expired ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 198

def is_batch_expired
  return !@batch.nil? && @batch.age() >= @batch_wait
end

#load_ssl ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 140

def load_ssl
  @cert = OpenSSL::X509::Certificate.new(File.read(@cert)) if @cert
  @key = OpenSSL::PKey.read(File.read(@key)) if @key
end

#loki_http_request(payload) ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 240

def loki_http_request(payload)
  req = Net::HTTP::Post.new(
    @uri.request_uri
  )
  req.add_field('Content-Type', 'application/json')
  #req.add_field('Content-Type', 'gzip')
  req.add_field('Content-Encoding', 'gzip')
  req.add_field('X-Scope-OrgID', @tenant_id) if @tenant_id
  req['User-Agent']= 'loki-logstash'
  req.basic_auth(@username, @password) if @username
  req.body = gzip(payload)

  opts = ssl_opts(@uri)

  @logger.debug("sending #{req.body.length} bytes to loki")
  retry_count = 0
  delay = @min_delay
  begin
    res = Net::HTTP.start(@uri.host, @uri.port, **opts) { |http|
      http.request(req)
    }
    return res if !res.nil? && res.code.to_i != 429 && res.code.to_i.div(100) != 5
    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)
    if retry_count < @retries
      sleep delay
      if delay * 2 <= @max_delay
        delay = delay * 2
      else
        delay = @max_delay
      end
      retry
    else
      @logger.error("Failed to send batch", :error_inspect => e.inspect, :error => e)
      return res
    end
  end
end

#max_batch_size ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 93

def max_batch_size
  loop do
    @mutex.synchronize do
      return if @stop
    end

    e = @entries.deq
    return if e.nil?

    @mutex.synchronize do
      if !add_entry_to_batch(e)
        @logger.debug("Max batch_size is reached. Sending batch to loki")
        send(@batch)
        @batch = Batch.new(e)
      end
    end
  end
end

#max_batch_wait ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 112

def max_batch_wait
  # minimum wait frequency is 10 milliseconds
 min_wait_checkfrequency = 1/100
 max_wait_checkfrequency = @batch_wait
 if max_wait_checkfrequency < min_wait_checkfrequency
  max_wait_checkfrequency = min_wait_checkfrequency
  end

  loop do
    @mutex.synchronize do
      return if @stop
    end

    sleep(max_wait_checkfrequency)
    if is_batch_expired
      @mutex.synchronize do
        @logger.debug("Max batch_wait time is reached. Sending batch to loki")
        send(@batch)
        @batch = nil
      end
    end
  end
end

#max_delay ⇒ Object

‘Backoff configuration. Maximum backoff time between retries. Default 300s’



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# File 'lib/logstash/outputs/loki.rb', line 55

config :max_delay, :validate => :number, :default => 300, :required => false

#message_field ⇒ Object

‘Log line field to pick from logstash. Defaults to “message”’



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# File 'lib/logstash/outputs/loki.rb', line 46

config :message_field, :validate => :string, :default => "message", :required => false

#min_delay ⇒ Object

‘Backoff configuration. Initial backoff time between retries. Default 1s’



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# File 'lib/logstash/outputs/loki.rb', line 49

config :min_delay, :validate => :number, :default => 1, :required => false

#receive(event) ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 204

def receive(event)
  @entries << Entry.new(event, @message_field, @include_fields)
end

#register ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 62

def register
  @uri = URI.parse(@url)
  unless @uri.is_a?(URI::HTTP) || @uri.is_a?(URI::HTTPS)
    raise LogStash::ConfigurationError, "url parameter must be valid HTTP, currently '#{@url}'"
  end

  if @min_delay > @max_delay
    raise LogStash::ConfigurationError, "Min delay should be less than Max delay, currently 'Min delay is #{@min_delay} and Max delay is #{@max_delay}'"
  end

  @logger.info("Loki output plugin", :class => self.class.name)

  # initialize Queue and Mutex
  @entries = Queue.new 
  @mutex = Mutex.new
  @stop = false

  # create nil batch object.
  @batch = nil

  # validate certs
  if ssl_cert?
    load_ssl
    validate_ssl_key
  end

  # start batch_max_wait and batch_max_size threads
  @batch_wait_thread = Thread.new{max_batch_wait()}
  @batch_size_thread = Thread.new{max_batch_size()}
end

#retries ⇒ Object

‘Backoff configuration. Maximum number of retries to do’



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# File 'lib/logstash/outputs/loki.rb', line 58

config :retries, :validate => :number, :default => 10, :required => false

#send(batch) ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 230

def send(batch)
  payload = batch.to_json
  res = loki_http_request(payload)
  if res.is_a?(Net::HTTPSuccess)
    @logger.debug("Successfully pushed data to loki")
  else
    @logger.debug("failed payload", :payload => payload)
  end
end

#single ⇒ Object

‘A single instance of the Output will be shared among the pipeline worker threads’



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# File 'lib/logstash/outputs/loki.rb', line 17

concurrency :single

#ssl_cert? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/outputs/loki.rb', line 136

def ssl_cert?
  !@key.nil? && !@cert.nil?
end

#ssl_opts(uri) ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 151

def ssl_opts(uri)
  opts = {
    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,
      cert: @cert,
      key: @key
    )
  end

  unless @ca_cert.nil?
    opts = opts.merge(
      ca_file: @ca_cert
    )
  end
  opts
end

#tenant_id ⇒ Object

‘Loki Tenant ID’



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# File 'lib/logstash/outputs/loki.rb', line 37

config :tenant_id, :validate => :string, :required => false

#url ⇒ Object

‘Loki URL’



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# File 'lib/logstash/outputs/loki.rb', line 20

config :url, :validate => :string, :required => true

#username ⇒ Object

‘BasicAuth credentials’



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# File 'lib/logstash/outputs/loki.rb', line 23

config :username, :validate => :string, :required => false

#validate_ssl_key ⇒ Object 



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# File 'lib/logstash/outputs/loki.rb', line 145

def validate_ssl_key
  if !@key.is_a?(OpenSSL::PKey::RSA) && !@key.is_a?(OpenSSL::PKey::DSA)
    raise LogStash::ConfigurationError, "Unsupported private key type '#{@key.class}''"
  end
end