Class: Fluent::Plugin::KubernetesMetadataFilter

Inherits:
Filter
  • Object
show all
Includes:
KubernetesMetadata::CacheStrategy, KubernetesMetadata::Common, KubernetesMetadata::WatchNamespaces, KubernetesMetadata::WatchPods
Defined in:
lib/fluent/plugin/filter_kubernetes_metadata.rb

Constant Summary collapse

K8_POD_CA_CERT = 
'ca.crt'
K8_POD_TOKEN = 
'token'
REGEX_VAR_LOG_PODS = 
'(var\.log\.pods)\.(?<namespace>[^_]+)_(?<pod_name>[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*)_(?<pod_uuid>[a-z0-9-]*)\.(?<container_name>.+)\..*\.log$'
REGEX_VAR_LOG_CONTAINERS = 
'(var\.log\.containers)\.(?<pod_name>[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*)_(?<namespace>[^_]+)_(?<container_name>.+)-(?<docker_id>[a-z0-9]{64})\.log$'

Instance Method Summary collapse

Methods included from KubernetesMetadata::WatchPods

#get_pods_and_start_watcher, #process_pod_watcher_notices, #reset_pod_watch_retry_stats, #set_up_pod_thread, #start_pod_watch

Methods included from KubernetesMetadata::Common

#match_annotations, #parse_namespace_metadata, #parse_pod_metadata, #syms_to_strs

Methods included from KubernetesMetadata::WatchNamespaces

#get_namespaces_and_start_watcher, #process_namespace_watcher_notices, #reset_namespace_watch_retry_stats, #set_up_namespace_thread, #start_namespace_watch

Methods included from KubernetesMetadata::CacheStrategy

#get_pod_metadata

Constructor Details

#initialize ⇒ KubernetesMetadataFilter

Returns a new instance of KubernetesMetadataFilter.



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 170

def initialize
  super
  @prev_time = Time.now
  @ssl_options = {}
  @auth_options = {}
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 177

def configure(conf)
  super

  require 'kubeclient'
  require 'lru_redux'

  @stats = KubernetesMetadata::Stats.new
  if @stats_interval <= 0
    @stats = KubernetesMetadata::NoOpStats.new
    self.define_singleton_method(:dump_stats) {}
  end

  if @cache_ttl < 0
    log.info 'Setting the cache TTL to :none because it was <= 0'
    @cache_ttl = :none
  end

  # Caches pod/namespace UID tuples for a given container UID.
  @id_cache = LruRedux::TTL::ThreadSafeCache.new(@cache_size, @cache_ttl)

  # Use the container UID as the key to fetch a hash containing pod metadata
  @cache = LruRedux::TTL::ThreadSafeCache.new(@cache_size, @cache_ttl)

  # Use the namespace UID as the key to fetch a hash containing namespace metadata
  @namespace_cache = LruRedux::TTL::ThreadSafeCache.new(@cache_size, @cache_ttl)

  @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?
    log.debug 'Kubernetes URL is not set - inspecting environ'

    env_host = ENV['KUBERNETES_SERVICE_HOST']
    env_port = ENV['KUBERNETES_SERVICE_PORT']
    if present?(env_host) && present?(env_port)
      if env_host =~ Resolv::IPv6::Regex
        # Brackets are needed around IPv6 addresses
        env_host = "[#{env_host}]"
      end
      @kubernetes_url = "https://#{env_host}:#{env_port}/api"
      log.debug "Kubernetes URL is now '#{@kubernetes_url}'"
    else
      log.debug 'No Kubernetes URL could be found in config or environ'
    end
  end

  # Use SSL certificate and bearer token from Kubernetes service account.
  if Dir.exist?(@secret_dir)
    log.debug "Found directory with secrets: #{@secret_dir}"
    ca_cert = File.join(@secret_dir, K8_POD_CA_CERT)
    pod_token = File.join(@secret_dir, K8_POD_TOKEN)

    if !present?(@ca_file) && File.exist?(ca_cert)
      log.debug "Found CA certificate: #{ca_cert}"
      @ca_file = ca_cert
    end

    if !present?(@bearer_token_file) && File.exist?(pod_token)
      log.debug "Found pod token: #{pod_token}"
      @bearer_token_file = pod_token
    end
  end

  if present?(@kubernetes_url)
    @ssl_options = {
      client_cert: present?(@client_cert) ? OpenSSL::X509::Certificate.new(File.read(@client_cert)) : nil,
      client_key: present?(@client_key) ? 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
    }

    if @ssl_partial_chain
      # taken from the ssl.rb OpenSSL::SSL::SSLContext code for DEFAULT_CERT_STORE
      require 'openssl'
      ssl_store = OpenSSL::X509::Store.new
      ssl_store.set_default_paths
      flagval = if defined? OpenSSL::X509::V_FLAG_PARTIAL_CHAIN
                  OpenSSL::X509::V_FLAG_PARTIAL_CHAIN
                else
                  # this version of ruby does not define OpenSSL::X509::V_FLAG_PARTIAL_CHAIN
                  0x80000
                end
      ssl_store.flags = OpenSSL::X509::V_FLAG_CRL_CHECK_ALL | flagval
      @ssl_options[:cert_store] = ssl_store
    end

    if present?(@bearer_token_file)
      @auth_options[:bearer_token_file] = @bearer_token_file
    end

    create_client()

    if @test_api_adapter
      log.info "Extending client with test api adaper #{@test_api_adapter}"
      require_relative @test_api_adapter.underscore
      @client.extend(eval(@test_api_adapter))
    end

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

    if @watch
      if ENV['K8S_NODE_NAME'].nil? || ENV['K8S_NODE_NAME'].strip.empty?
        log.warn("!! The environment variable 'K8S_NODE_NAME' is not set to the node name which can affect the API server and watch efficiency !!")
      end

      pod_thread = Thread.new(self, &:set_up_pod_thread)
      pod_thread.abort_on_exception = true

      namespace_thread = Thread.new(self, &:set_up_namespace_thread)
      namespace_thread.abort_on_exception = true
    end
  end

  @annotations_regexps = []
  @annotation_match.each do |regexp|
    @annotations_regexps << Regexp.compile(regexp)
  rescue RegexpError => e
    log.error "Error: invalid regular expression in annotation_match: #{e}"
  end
end

#create_client ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 302

def create_client()
  log.debug 'Creating K8S client'
  @client = nil
  @client = Kubeclient::Client.new(
    @kubernetes_url,
    @apiVersion,
    ssl_options: @ssl_options,
    auth_options: @auth_options,
    timeouts: {
      open: @open_timeout,
      read: @read_timeout
    },
    as: :parsed_symbolized
  )
end

#dump_stats ⇒ Object 



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

def dump_stats
  @curr_time = Time.now
  return if @curr_time.to_i - @prev_time.to_i < @stats_interval

  @prev_time = @curr_time
  @stats.set(:pod_cache_size, @cache.count)
  @stats.set(:namespace_cache_size, @namespace_cache.count) if @namespace_cache
  log.info(@stats)
  if log.level == Fluent::Log::LEVEL_TRACE
    log.trace("       id cache: #{@id_cache.to_a}")
    log.trace("      pod cache: #{@cache.to_a}")
    log.trace("namespace cache: #{@namespace_cache.to_a}")
  end
end

#fetch_namespace_metadata(namespace_name) ⇒ Object 



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

def fetch_namespace_metadata(namespace_name)
  log.trace("fetching namespace metadata: #{namespace_name}")
  options = {
    resource_version: '0' # Fetch from API server cache instead of etcd quorum read
  }
  namespace_object = @client.get_namespace(namespace_name, nil, options)
  log.trace("raw metadata for #{namespace_name}: #{namespace_object}")
  metadata = parse_namespace_metadata(namespace_object)
  @stats.bump(:namespace_cache_api_updates)
  log.trace("parsed metadata for #{namespace_name}: #{metadata}")
  @namespace_cache[metadata['namespace_id']] = metadata
  rescue KubeException => e
    if e.error_code == 401
      # recreate client to refresh token
      log.info("Encountered '401 Unauthorized' exception, recreating client to refresh token")
      create_client()
    else
      log.error "Exception '#{e}' encountered fetching namespace metadata from Kubernetes API #{@apiVersion} endpoint #{@kubernetes_url}"
      @stats.bump(:namespace_cache_api_nil_error)
    end
    {}
  rescue StandardError => e
    @stats.bump(:namespace_cache_api_nil_error)
    log.error "Exception '#{e}' encountered fetching namespace metadata from Kubernetes API #{@apiVersion} endpoint #{@kubernetes_url}"
    {}
end

#fetch_pod_metadata(namespace_name, pod_name) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 98

def fetch_pod_metadata(namespace_name, pod_name)
log.trace("fetching pod metadata: #{namespace_name}/#{pod_name}")
options = {
  resource_version: '0' # Fetch from API server cache instead of etcd quorum read
}
pod_object = @client.get_pod(pod_name, namespace_name, options)
log.trace("raw metadata for #{namespace_name}/#{pod_name}: #{pod_object}")
metadata = parse_pod_metadata(pod_object)
@stats.bump(:pod_cache_api_updates)
log.trace("parsed metadata for #{namespace_name}/#{pod_name}: #{metadata}")
@cache[metadata['pod_id']] = metadata
rescue KubeException => e
  if e.error_code == 401
    # recreate client to refresh token
    log.info("Encountered '401 Unauthorized' exception, recreating client to refresh token")
    create_client()
  elsif e.error_code == 404
    log.debug "Encountered '404 Not Found' exception, pod not found"
    @stats.bump(:pod_cache_api_nil_error)
  else
    log.error "Exception '#{e}' encountered fetching pod metadata from Kubernetes API #{@apiVersion} endpoint #{@kubernetes_url}"
    @stats.bump(:pod_cache_api_nil_error)
  end
  {}
rescue StandardError => e
  @stats.bump(:pod_cache_api_nil_error)
  log.error "Exception '#{e}' encountered fetching pod metadata from Kubernetes API #{@apiVersion} endpoint #{@kubernetes_url}"
  {}
end

#filter(tag, time, record) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 349

def filter(tag, time, record)
  tag_match_data = tag.match(@tag_to_kubernetes_name_regexp_compiled)
  batch_miss_cache = {}
  if tag_match_data
    cache_key =  if tag_match_data.names.include?('pod_uuid') && !tag_match_data['pod_uuid'].nil?
      tag_match_data['pod_uuid']
    else
      tag_match_data['docker_id']
    end
    docker_id = tag_match_data.names.include?('docker_id') ? tag_match_data['docker_id'] : nil
    metadata = get_metadata_for_record(tag_match_data['namespace'], tag_match_data['pod_name'], tag_match_data['container_name'],
                                            cache_key, time, batch_miss_cache, docker_id)
  end
  if @lookup_from_k8s_field && record.key?('kubernetes') && record.key?('docker') &&
      record['kubernetes'].respond_to?(:has_key?) && record['docker'].respond_to?(:has_key?) &&
      record['kubernetes'].key?('namespace_name') &&
      record['kubernetes'].key?('pod_name') &&
      record['kubernetes'].key?('container_name') &&
      record['docker'].key?('container_id') &&
      (k_metadata = get_metadata_for_record(record['kubernetes']['namespace_name'], record['kubernetes']['pod_name'],
                                            record['kubernetes']['container_name'], record['docker']['container_id'],
                                            time, batch_miss_cache, record['docker']['container_id']))
    metadata = k_metadata
  end
  dump_stats
  metadata ? record.merge(metadata) : record
end

#get_metadata_for_record(namespace_name, pod_name, container_name, cache_key, create_time, batch_miss_cache, docker_id) ⇒ Object 



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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 318

def get_metadata_for_record(namespace_name, pod_name, container_name, cache_key, create_time, batch_miss_cache, docker_id)
  metadata = {
    'docker' => { 'container_id' => "" },
    'kubernetes' => {
      'container_name' => container_name,
      'namespace_name' => namespace_name,
      'pod_name' => pod_name
    }
  }
  metadata['docker']['container_id'] = docker_id unless docker_id.nil?
  container_cache_key = container_name
  if present?(@kubernetes_url)
    pod_metadata = get_pod_metadata(cache_key, namespace_name, pod_name, create_time, batch_miss_cache)
    if (pod_metadata.include? 'containers') && (pod_metadata['containers'].include? container_cache_key) && !@skip_container_metadata
      metadata['kubernetes']['container_image'] = pod_metadata['containers'][container_cache_key]['image']
      metadata['kubernetes']['container_image_id'] = pod_metadata['containers'][container_cache_key]['image_id'] unless pod_metadata['containers'][container_cache_key]['image_id'].empty?
      metadata['docker']['container_id'] = pod_metadata['containers'][container_cache_key]['containerID'] unless pod_metadata['containers'][container_cache_key]['containerID'].empty?
    end

    metadata['kubernetes'].merge!(pod_metadata) if pod_metadata
    metadata['kubernetes'].delete('containers')
  end
  metadata['kubernetes'].tap do |kube|
    kube.each_pair do |k,v|
      kube[k.dup] = v.dup
    end
  end
  metadata.delete('docker') if metadata['docker'] && (metadata['docker']['container_id'].nil? || metadata['docker']['container_id'].empty?)
  metadata
end

#present?(object) ⇒ Boolean

copied from activesupport

Returns:

  • (Boolean) 


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# File 'lib/fluent/plugin/filter_kubernetes_metadata.rb', line 378

def present?(object)
  object.respond_to?(:empty?) ? !object.empty? : !!object
end