Class: Fluent::KubernetesMetadataFilter

Inherits:
Filter
  • Object
show all
Defined in:
lib/fluent/plugin/filter_kubernetes_metadata.rb

Constant Summary collapse

K8_POD_CA_CERT = 
'ca.crt'
K8_POD_TOKEN = 
'token'

Instance Method Summary collapse

Constructor Details

#initialize ⇒ KubernetesMetadataFilter 



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

def initialize
  super
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 85

def configure(conf)
  super

  require 'kubeclient'
  require 'active_support/core_ext/object/blank'
  require 'lru_redux'

  if @de_dot && (@de_dot_separator =~ /\./).present?
    raise Fluent::ConfigError, "Invalid de_dot_separator: cannot be or contain '.'"
  end

  if @cache_ttl < 0
    @cache_ttl = :none
  end
  @cache = LruRedux::TTL::ThreadSafeCache.new(@cache_size, @cache_ttl)
  if @include_namespace_id
    @namespace_cache = LruRedux::TTL::ThreadSafeCache.new(@cache_size, @cache_ttl)
  end
  @tag_to_kubernetes_name_regexp_compiled = Regexp.compile(@tag_to_kubernetes_name_regexp)

  # Use Kubernetes default service account if we're in a pod.
  if @kubernetes_url.nil?
    env_host = ENV['KUBERNETES_SERVICE_HOST']
    env_port = ENV['KUBERNETES_SERVICE_PORT']
    if env_host.present? && env_port.present?
      @kubernetes_url = "https://#{env_host}:#{env_port}/api"
    end
  end

  # Use SSL certificate and bearer token from Kubernetes service account.
  if Dir.exist?(@secret_dir)
    ca_cert = File.join(@secret_dir, K8_POD_CA_CERT)
    pod_token = File.join(@secret_dir, K8_POD_TOKEN)

    if !@ca_file.present? and File.exist?(ca_cert)
      @ca_file = ca_cert
    end

    if !@bearer_token_file.present? and File.exist?(pod_token)
      @bearer_token_file = pod_token
    end
  end

  if @kubernetes_url.present?

    ssl_options = {
        client_cert: @client_cert.present? ? OpenSSL::X509::Certificate.new(File.read(@client_cert)) : nil,
        client_key:  @client_key.present? ? OpenSSL::PKey::RSA.new(File.read(@client_key)) : nil,
        ca_file:     @ca_file,
        verify_ssl:  @verify_ssl ? OpenSSL::SSL::VERIFY_PEER : OpenSSL::SSL::VERIFY_NONE
    }

    auth_options = {}

    if @bearer_token_file.present?
      bearer_token = File.read(@bearer_token_file)
      auth_options[:bearer_token] = bearer_token
    end

    @client = Kubeclient::Client.new @kubernetes_url, @apiVersion,
                                     ssl_options: ssl_options,
                                     auth_options: auth_options

    begin
      @client.api_valid?
    rescue KubeException => kube_error
      raise Fluent::ConfigError, "Invalid Kubernetes API endpoint: #{kube_error.message}"
    end

    if @watch
      thread = Thread.new(self) { |this| this.start_watch }
      thread.abort_on_exception = true
      if @include_namespace_id
        namespace_thread = Thread.new(self) { |this| this.start_namespace_watch }
        namespace_thread.abort_on_exception = true
      end
    end
  end
end

#de_dot!(h) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 234

def de_dot!(h)
  h.keys.each do |ref|
    if h[ref] && ref =~ /\./
      v = h.delete(ref)
      newref = ref.to_s.gsub('.', @de_dot_separator)
      h[newref] = v
    end
  end
end

#filter_stream(tag, es) ⇒ Object

NOTE: fluentd requires that records/hashes have string keys, not symbol keys docs.fluentd.org/articles/plugin-development#record-format



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 167

def filter_stream(tag, es)
  new_es = MultiEventStream.new

  match_data = tag.match(@tag_to_kubernetes_name_regexp_compiled)

  if match_data
    metadata = {
        'docker' => {
            'container_id' => match_data['docker_id']
        },
        'kubernetes' => {
            'namespace_name' => match_data['namespace'],
            'pod_name'       => match_data['pod_name'],
            'container_name' => match_data['container_name']
        }
    }

    if @kubernetes_url.present?
      cache_key = "#{metadata['kubernetes']['namespace_name']}_#{metadata['kubernetes']['pod_name']}_#{metadata['kubernetes']['container_name']}"

      this     = self
      metadata = @cache.getset(cache_key) {
        if metadata
          kubernetes_metadata = this.get_metadata(
            metadata['kubernetes']['namespace_name'],
            metadata['kubernetes']['pod_name'],
            metadata['kubernetes']['container_name']
          )
          metadata['kubernetes'] = kubernetes_metadata if kubernetes_metadata
          metadata
        end
      }
      if @include_namespace_id
        namespace_name = metadata['kubernetes']['namespace_name']
        namespace_id = @namespace_cache.getset(namespace_name) {
          namespace = @client.get_namespace(namespace_name)
          namespace['metadata']['uid'] if namespace
        }
        metadata['kubernetes']['namespace_id'] = namespace_id if namespace_id
      end
    end
  end

  es.each { |time, record|
    record = merge_json_log(record) if @merge_json_log

    record = record.merge(metadata) if metadata

    new_es.add(time, record)
  }

  new_es
end

#get_metadata(namespace_name, pod_name, container_name) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 60

def get_metadata(namespace_name, pod_name, container_name)
  begin
    metadata = @client.get_pod(pod_name, namespace_name)
    return if !metadata
    labels = syms_to_strs(metadata['metadata']['labels'].to_h)
    if @de_dot
      self.de_dot!(labels)
    end
    return {
        'namespace_name' => namespace_name,
        'pod_id'         => metadata['metadata']['uid'],
        'pod_name'       => pod_name,
        'container_name' => container_name,
        'labels'         => labels,
        'host'           => metadata['spec']['nodeName']
    }
  rescue KubeException
    nil
  end
end

#merge_json_log(record) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 221

def merge_json_log(record)
  if record.has_key?('log')
    log = record['log'].strip
    if log[0].eql?('{') && log[-1].eql?('}')
      begin
        record = JSON.parse(log).merge(record)
      rescue JSON::ParserError
      end
    end
  end
  record
end

#start_namespace_watch ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 286

def start_namespace_watch
  resource_version = @client.get_namespaces.resourceVersion
  watcher          = @client.watch_namespaces(resource_version)
  watcher.each do |notice|
    puts notice
    case notice.type
      when 'DELETED'
        @namespace_cache.delete(notice.object['metadata']['name'])
      else
        # We only care about each namespace's name and UID, neither of which
        # is modifiable, so we only have to care about deletions.
    end
  end
end

#start_watch ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 244

def start_watch
  begin
    resource_version = @client.get_pods.resourceVersion
    watcher          = @client.watch_pods(resource_version)
  rescue Exception => e
    raise Fluent::ConfigError, "Exception encountered fetching metadata from Kubernetes API endpoint: #{e.message}"
  end

  watcher.each do |notice|
    case notice.type
      when 'MODIFIED'
        if notice.object.status.containerStatuses
          pod_cache_key = "#{notice.object['metadata']['namespace']}_#{notice.object['metadata']['name']}"
          notice.object.status.containerStatuses.each { |container_status|
            cache_key = "#{pod_cache_key}_#{container_status['name']}"
            cached    = @cache[cache_key]
            if cached
              # Only thing that can be modified is labels
              labels = syms_to_strs(notice.object.metadata.labels.to_h)
              if @de_dot
                self.de_dot!(labels)
              end
              cached['kubernetes']['labels'] = labels
              @cache[cache_key]            = cached
            end
          }
        end
      when 'DELETED'
        if notice.object.status.containerStatuses
          pod_cache_key = "#{notice.object['metadata']['namespace']}_#{notice.object['metadata']['name']}"
          notice.object.status.containerStatuses.each { |container_status|
            cache_key = "#{pod_cache_key}_#{container_status['name']}"
            @cache.delete(cache_key)
          }
        end
      else
        # Don't pay attention to creations, since the created pod may not
        # end up on this node.
    end
  end
end

#syms_to_strs(hsh) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 45

def syms_to_strs(hsh)
  newhsh = {}
  hsh.each_pair do |kk,vv|
    if vv.is_a?(Hash)
      vv = syms_to_strs(vv)
    end
    if kk.is_a?(Symbol)
      newhsh[kk.to_s] = vv
    else
      newhsh[kk] = vv
    end
  end
  newhsh
end