Class: K8s::Transport

Inherits:
Object
  • Object
show all
Includes:
Logging
Defined in:
lib/k8s/transport.rb

Overview

Excon-based HTTP transport handling request/response body JSON encoding

Constant Summary collapse

EXCON_MIDDLEWARES =

Excon middlewares for requests

[
  # XXX: necessary? redirected requests omit authz headers?
  Excon::Middleware::RedirectFollower,
]
REQUEST_HEADERS =

Default request headers

{
  'Accept' => 'application/json',
}

Constants included from Logging

Logging::LOG_LEVEL, Logging::LOG_TARGET

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Logging

included, #logger, #logger!

Methods included from Logging::ModuleMethods

#debug!, #log_level, #log_level=, #quiet!, #verbose!

Constructor Details

#initialize(server, auth_token: nil, **options) ⇒ Transport

Returns a new instance of Transport.

Parameters:

  • server (String) —

    URL with protocol://host:port - any /path is ignored

  • auth_token (String) (defaults to: nil) —

    optional Authorization: Bearer token

  • options (Hash) —

    @see Excon.new



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# File 'lib/k8s/transport.rb', line 96

def initialize(server, auth_token: nil, **options)
  @server = server
  @auth_token = auth_token
  @options = options

  logger! progname: @server
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/k8s/transport.rb', line 91

def options
  @options
end

#server ⇒ Object (readonly)

Returns the value of attribute server.



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# File 'lib/k8s/transport.rb', line 91

def server
  @server
end

Class Method Details

.config(config, server: nil, **overrides) ⇒ K8s::Transport

Construct transport from kubeconfig

Parameters:

  • config (K8s::Config)
  • server (String) (defaults to: nil) —

    override cluster.server from config

  • overrides —

    @see #initialize

Returns:



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# File 'lib/k8s/transport.rb', line 28

def self.config(config, server: nil, **overrides)
  options = {}

  server ||= config.cluster.server

  if config.cluster.insecure_skip_tls_verify
    logger.debug "Using config with .cluster.insecure_skip_tls_verify"

    options[:ssl_verify_peer] = false
  end

  if path = config.cluster.certificate_authority
    logger.debug "Using config with .cluster.certificate_authority"

    options[:ssl_ca_file] = path
  end

  if data = config.cluster.certificate_authority_data
    logger.debug "Using config with .cluster.certificate_authority_data"

    ssl_cert_store = options[:ssl_cert_store] = OpenSSL::X509::Store.new
    ssl_cert_store.add_cert(OpenSSL::X509::Certificate.new(Base64.decode64(data)))
  end

  if (cert = config.user.client_certificate) && (key = config.user.client_key)
    logger.debug "Using config with .user.client_certificate/client_key"

    options[:client_cert] = cert
    options[:client_key] = key
  end

  if (cert_data = config.user.client_certificate_data) && (key_data = config.user.client_key_data)
    logger.debug "Using config with .user.client_certificate_data/client_key_data"

    options[:client_cert_data] = Base64.decode64(cert_data)
    options[:client_key_data] = Base64.decode64(key_data)
  end

  if token = config.user.token
    logger.debug "Using config with .user.token=..."

    options[:auth_token] = token
  end

  logger.info "Using config with server=#{server}"

  new(server, **options, **overrides)
end

.in_cluster_config ⇒ K8s::Transport

In-cluster config within a kube pod, using the kubernetes service envs and serviceaccount secrets

Returns:



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# File 'lib/k8s/transport.rb', line 80

def self.in_cluster_config
  host = ENV['KUBERNETES_SERVICE_HOST']
  port = ENV['KUBERNETES_SERVICE_PORT_HTTPS']

  new("https://#{host}:#{port}",
    ssl_verify_peer: true,
    ssl_ca_file: '/var/run/secrets/kubernetes.io/serviceaccount/ca.crt',
    auth_token: File.read('/var/run/secrets/kubernetes.io/serviceaccount/token'),
  )
end

Instance Method Details

#excon ⇒ Excon::Connection

Returns:

  • (Excon::Connection) 


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# File 'lib/k8s/transport.rb', line 105

def excon
  @excon ||= Excon.new(@server,
    persistent: true,
    middlewares: EXCON_MIDDLEWARES,
    headers: REQUEST_HEADERS,
    **@options
  )
end

#format_request(options) ⇒ Object

Parameters:

  • options (Hash) —

    as passed to Excon#request



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# File 'lib/k8s/transport.rb', line 140

def format_request(options)
  method = options[:method]
  path = options[:path]
  body = nil

  if options[:query]
    path += Excon::Utils.query_string(options)
  end
  if obj = options[:request_object]
    body = "<#{obj.class.name}>"
  end

  [method, path, body].compact.join " "
end

#get(*path, **options) ⇒ Object

Parameters:

  • path (Array<String>) —

    @see #path

  • options (Hash) —

    @see #request



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# File 'lib/k8s/transport.rb', line 280

def get(*path, **options)
  request(
    method: 'GET',
    path: self.path(*path),
    **options,
  )
end

#gets(*paths, **options) ⇒ Object

Parameters:

  • paths (Array<String>)
  • options (Hash) —

    @see #request



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# File 'lib/k8s/transport.rb', line 290

def gets(*paths, **options)
  requests(*paths.map{|path| {
      method: 'GET',
      path: self.path(path),
    } },
    **options
  )
end

#parse_response(response, request_options, response_class: nil) ⇒ response_class, Hash

Parameters:

  • response (Hash) —

    as returned by Excon#request

  • request_options (Hash) —

    as passed to Excon#request

  • response_class (Class) (defaults to: nil) —

    decode response body using #from_json

Returns:

  • (response_class, Hash)

Raises:



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# File 'lib/k8s/transport.rb', line 161

def parse_response(response, request_options, response_class: nil)
  method = request_options[:method]
  path = request_options[:path]
  content_type, = response.headers['Content-Type'].split(';')

  case content_type
  when 'application/json'
    response_data = JSON.parse(response.body)

  when 'text/plain'
    response_data = response.body # XXX: broken if status 2xx
  else
    raise K8s::Error::API.new(method, path, response.status, "Invalid response Content-Type: #{response.headers['Content-Type']}")
  end

  if response.status.between? 200, 299
    unless response_data.is_a? Hash
      raise K8s::Error::API.new(method, path, response.status, "Invalid JSON response: #{response_data.inspect}")
    end

    if response_class
      return response_class.from_json(response_data)
    else
      return response_data # Hash
    end
  else
    error_class = K8s::Error::HTTP_STATUS_ERRORS[response.status] || K8s::Error::API

    if response_data.is_a?(Hash) && response_data['kind'] == 'Status'
      status = K8s::API::MetaV1::Status.new(response_data)

      raise error_class.new(method, path, response.status, response.reason_phrase, status)
    elsif response_data
      raise error_class.new(method, path, response.status, "#{response.reason_phrase}: #{response_data}")
    else
      raise error_class.new(method, path, response.status, response.reason_phrase)
    end
  end
end

#path(*path) ⇒ String

Parameters:

  • path (Array<String>) —

    join path parts together to build the full URL

Returns:

  • (String) 


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# File 'lib/k8s/transport.rb', line 116

def path(*path)
  File.join('/', *path)
end

#request(response_class: nil, **options) ⇒ Object

Parameters:

  • response_class (Class) (defaults to: nil) —

    decode response body using #from_json

  • options (Hash) —

    @see Excon#request



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# File 'lib/k8s/transport.rb', line 203

def request(response_class: nil, **options)
  excon_options = request_options(**options)

  start = Time.now
  response = excon.request(**excon_options)
  t = Time.now - start

  obj = parse_response(response, options,
    response_class: response_class,
  )
rescue K8s::Error::API => exc
  logger.warn { "#{format_request(options)} => HTTP #{exc.code} #{exc.reason} in #{'%.3f' % t}s"}
  logger.debug { "Request: #{excon_options[:body]}"} if excon_options[:body]
  logger.debug { "Response: #{response.body}"}
  raise
else
  logger.info { "#{format_request(options)} => HTTP #{response.status}: <#{obj.class}> in #{'%.3f' % t}s"}
  logger.debug { "Request: #{excon_options[:body]}"} if excon_options[:body]
  logger.debug { "Response: #{response.body}"}
  return obj
end

#request_options(request_object: nil, content_type: 'application/json', **options) ⇒ Hash

Parameters:

  • request_object (Object) (defaults to: nil) —

    include request body using to_json

  • content_type (String) (defaults to: 'application/json') —

    request body content-type

  • options (Hash) —

    @see Excon#request

Returns:

  • (Hash) 


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# File 'lib/k8s/transport.rb', line 124

def request_options(request_object: nil, content_type: 'application/json', **options)
  options[:headers] ||= {}

  if @auth_token
    options[:headers]['Authorization'] = "Bearer #{@auth_token}"
  end

  if request_object
    options[:headers]['Content-Type'] = content_type
    options[:body] = request_object.to_json
  end

  options
end

#requests(*options, skip_missing: false, skip_forbidden: false, retry_errors: true, **common_options) ⇒ Array<response_class, Hash, nil>

Parameters:

  • options (Array<Hash>) —

    @see #request

  • skip_missing (Boolean) (defaults to: false) —

    return nil for HTTP 404 responses

  • skip_forbidden (Boolean) (defaults to: false) —

    return nil for HTTP 403 responses

  • retry_errors (Boolean) (defaults to: true) —

    retry with non-pipelined request for HTTP 503 responses

  • common_options (Hash) —

    @see #request, merged with the per-request options

Returns:

  • (Array<response_class, Hash, nil>) 


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# File 'lib/k8s/transport.rb', line 231

def requests(*options, skip_missing: false, skip_forbidden: false, retry_errors: true, **common_options)
  return [] if options.empty? # excon chokes

  start = Time.now
  responses = excon.requests(
    options.map{|options| request_options(**common_options.merge(options))}
  )
  t = Time.now - start

  objects = responses.zip(options).map{|response, request_options|
    response_class = request_options[:response_class] || common_options[:response_class]

    begin
      parse_response(response, request_options,
        response_class: response_class,
      )
    rescue K8s::Error::NotFound
      if skip_missing
        nil
      else
        raise
      end
    rescue K8s::Error::Forbidden
      if skip_forbidden
        nil
      else
        raise
      end
    rescue K8s::Error::ServiceUnavailable => exc
      if retry_errors
        logger.warn { "Retry #{format_request(request_options)} => HTTP #{exc.code} #{exc.reason} in #{'%.3f' % t}s" }

        # only retry the failed request, not the entire pipeline
        request(response_class: response_class, **common_options.merge(request_options))
      else
        raise
      end
    end
  }
rescue K8s::Error => exc
  logger.warn { "[#{options.map{|o| format_request(o)}.join ', '}] => HTTP #{exc.code} #{exc.reason} in #{'%.3f' % t}s"}
  raise
else
  logger.info { "[#{options.map{|o| format_request(o)}.join ', '}] => HTTP [#{responses.map{|r| r.status}.join ', '}] in #{'%.3f' % t}s" }
  return objects
end