Class: Fluent::Plugin::LokiOutput

Inherits:
Output
  • Object
show all
Defined in:
lib/fluent/plugin/out_loki.rb

Overview

Subclass of Fluent Plugin Output

Defined Under Namespace

Classes: LogPostError

Constant Summary collapse

DEFAULT_BUFFER_TYPE = 
'memory'

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#record_accessors ⇒ Object

Returns the value of attribute record_accessors.



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# File 'lib/fluent/plugin/out_loki.rb', line 34

def record_accessors
  @record_accessors
end

Instance Method Details

#client_cert_configured? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fluent/plugin/out_loki.rb', line 128

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

#configure(conf) ⇒ Object

rubocop:disable Metrics/CyclomaticComplexity



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# File 'lib/fluent/plugin/out_loki.rb', line 81

def configure(conf) # rubocop:disable Metrics/CyclomaticComplexity
  compat_parameters_convert(conf, :buffer)
  super
  @uri = URI.parse(@url + '/loki/api/v1/push')
  unless @uri.is_a?(URI::HTTP) || @uri.is_a?(URI::HTTPS)
    raise Fluent::ConfigError, 'URL parameter must have HTTP/HTTPS scheme'
  end

  @record_accessors = {}
  conf.elements.select { |element| element.name == 'label' }.each do |element|
    element.each_pair do |k, v|
      element.has_key?(k) # rubocop:disable Style/PreferredHashMethods #to suppress unread configuration warning
      v = k if v.empty?
      @record_accessors[k] = record_accessor_create(v)
    end
  end
  @remove_keys_accessors = []
  @remove_keys.each do |key|
    @remove_keys_accessors.push(record_accessor_create(key))
  end

  # If configured, load and validate client certificate (and corresponding key)
  if client_cert_configured?
    load_client_cert
    validate_client_cert_key
  end

  raise "bearer_token_file #{@bearer_token_file} not found" if !@bearer_token_file.nil? && !File.exist?(@bearer_token_file)

  @auth_token_bearer = nil
  if !@bearer_token_file.nil?
    if !File.exist?(@bearer_token_file)
      raise "bearer_token_file #{@bearer_token_file} not found"
    end

    # Read the file once, assume long-lived authentication token.
    @auth_token_bearer = File.read(@bearer_token_file)
    if @auth_token_bearer.empty?
      raise "bearer_token_file #{@bearer_token_file} is empty"
    end
    log.info "will use Bearer token from bearer_token_file #{@bearer_token_file} in Authorization header"
  end


  raise "CA certificate file #{@ca_cert} not found" if !@ca_cert.nil? && !File.exist?(@ca_cert)
end

#generic_to_loki(chunk) ⇒ Object 



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# File 'lib/fluent/plugin/out_loki.rb', line 201

def generic_to_loki(chunk)
  # log.debug("GenericToLoki: converting #{chunk}")
  streams = chunk_to_loki(chunk)
  payload = payload_builder(streams)
  payload
end

#http_request_opts(uri) ⇒ Object 



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# File 'lib/fluent/plugin/out_loki.rb', line 171

def http_request_opts(uri)
  opts = {
    use_ssl: uri.scheme == 'https'
  }

  # Optionally disable server server certificate verification.
  if @insecure_tls
    opts = opts.merge(
      verify_mode: OpenSSL::SSL::VERIFY_NONE
    )
  end

  # Optionally present client certificate
  if !@cert.nil? && !@key.nil?
    opts = opts.merge(
      cert: @cert,
      key: @key
    )
  end

  # For server certificate verification: set custom CA bundle.
  # Only takes effect when `insecure_tls` is not set.
  unless @ca_cert.nil?
    opts = opts.merge(
      ca_file: @ca_cert
    )
  end
  opts
end

#load_client_cert ⇒ Object 



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# File 'lib/fluent/plugin/out_loki.rb', line 132

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

#multi_workers_ready? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fluent/plugin/out_loki.rb', line 143

def multi_workers_ready?
  true
end

#validate_client_cert_key ⇒ Object 



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# File 'lib/fluent/plugin/out_loki.rb', line 137

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

#write(chunk) ⇒ Object

flush a chunk to loki

Raises:



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# File 'lib/fluent/plugin/out_loki.rb', line 148

def write(chunk)
  # streams by label
  payload = generic_to_loki(chunk)
  body = { 'streams' => payload }

  tenant = extract_placeholders(@tenant, chunk) if @tenant

  # add ingest path to loki url
  res = loki_http_request(body, tenant)

  if res.is_a?(Net::HTTPSuccess)
    log.debug "POST request was responded to with status code #{res.code}"
    return
  end

  res_summary = "#{res.code} #{res.message} #{res.body}"
  log.warn "failed to write post to #{@uri} (#{res_summary})"
  log.debug Yajl.dump(body)

  # Only retry 429 and 500s
  raise(LogPostError, res_summary) if res.is_a?(Net::HTTPTooManyRequests) || res.is_a?(Net::HTTPServerError)
end