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'
}.freeze
DELETE_OPTS_BODY_VERSION_MIN =

Min version of Kube API for which delete options need to be sent as request body

Gem::Version.new('1.11')

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, auth_username: nil, auth_password: nil, **options) ⇒ Transport 



152
153
154
155
156
157
158
159
160
161
162
 
# File 'lib/k8s/transport.rb', line 152

def initialize(server, auth_token: nil, auth_username: nil, auth_password: nil, **options)
  uri = URI.parse(server)
  @server = "#{uri.scheme}://#{uri.host}:#{uri.port}"
  @path_prefix = File.join('/', uri.path, '/') # add leading and/or trailing slashes
  @auth_token = auth_token
  @auth_username = auth_username
  @auth_password = auth_password
  @options = options

  logger! progname: @server
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



145
146
147
 
# File 'lib/k8s/transport.rb', line 145

def options
  @options
end

#path_prefix ⇒ Object (readonly)

Returns the value of attribute path_prefix.



145
146
147
 
# File 'lib/k8s/transport.rb', line 145

def path_prefix
  @path_prefix
end

#server ⇒ Object (readonly)

Returns the value of attribute server.



145
146
147
 
# File 'lib/k8s/transport.rb', line 145

def server
  @server
end

Class Method Details

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

Construct transport from kubeconfig



34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
 
# File 'lib/k8s/transport.rb', line 34

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
  elsif config.user.auth_provider && auth_provider_config = config.user.auth_provider.config
    logger.debug "Using config with .user.auth-provider.name=#{config.user.auth_provider.name}"
    options[:auth_token] = token_from_auth_provider_config(auth_provider_config)
  elsif exec_conf = config.user.exec
    logger.debug "Using config with .user.exec.command=#{exec_conf.command}"
    options[:auth_token] = token_from_exec(exec_conf)
  elsif config.user.username && config.user.password
    logger.debug "Using config with .user.password=..."

    options[:auth_username] = config.user.username
    options[:auth_password] = config.user.password
  end

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

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

.in_cluster_config(**options) ⇒ K8s::Transport

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

Raises:

  • (K8s::Error::Config) —

    when the environment variables KUBERNETES_SEVICE_HOST and KUBERNETES_SERVICE_PORT_HTTPS are not set

  • (Errno::ENOENT, Errno::EACCES) —

    when /var/run/secrets/kubernetes.io/serviceaccount/ca.crt or /var/run/secrets/kubernetes.io/serviceaccount/token can not be read



129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
 
# File 'lib/k8s/transport.rb', line 129

def self.in_cluster_config(**options)
  host = ENV['KUBERNETES_SERVICE_HOST'].to_s
  raise(K8s::Error::Configuration, "in_cluster_config failed: KUBERNETES_SERVICE_HOST environment not set") if host.empty?

  port = ENV['KUBERNETES_SERVICE_PORT_HTTPS'].to_s
  raise(K8s::Error::Configuration, "in_cluster_config failed: KUBERNETES_SERVICE_PORT_HTTPS environment not set") if port.empty?

  new(
    "https://#{host}:#{port}",
    ssl_verify_peer: options.key?(:ssl_verify_peer) ? options.delete(:ssl_verify_peer) : true,
    ssl_ca_file: options.delete(:ssl_ca_file) || File.join((ENV['TELEPRESENCE_ROOT'] || '/'), 'var/run/secrets/kubernetes.io/serviceaccount/ca.crt'),
    auth_token: options.delete(:auth_token) || File.read(File.join((ENV['TELEPRESENCE_ROOT'] || '/'), 'var/run/secrets/kubernetes.io/serviceaccount/token')),
    **options
  )
end

.token_from_auth_provider_config(auth_provider_config) ⇒ String 



96
97
98
99
100
101
102
103
104
 
# File 'lib/k8s/transport.rb', line 96

def self.token_from_auth_provider_config(auth_provider_config)
  auth_data = `#{auth_provider_config['cmd-path']} #{auth_provider_config['cmd-args']}`.strip
  if auth_provider_config['token-key']
    json_path = JsonPath.new(auth_provider_config['token-key'][1...-1])
    json_path.first(auth_data)
  else
    auth_data
  end
end

.token_from_exec(exec_conf) ⇒ String 



108
109
110
111
112
113
114
115
116
117
118
119
120
121
 
# File 'lib/k8s/transport.rb', line 108

def self.token_from_exec(exec_conf)
  cmd = [exec_conf.command]
  cmd += exec_conf.args if exec_conf.args
  orig_env = ENV.to_h
  if envs = exec_conf.env
    envs.each do |env|
      ENV[env['name']] = env['value']
    end
  end
  auth_json = `#{cmd.join(' ')}`.strip
  ENV.replace(orig_env)

  JSON.parse(auth_json).dig('status', 'token')
end

Instance Method Details

#build_excon ⇒ Excon::Connection 



170
171
172
173
174
175
176
177
178
 
# File 'lib/k8s/transport.rb', line 170

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

#excon ⇒ Excon::Connection 



165
166
167
 
# File 'lib/k8s/transport.rb', line 165

def excon
  @excon ||= build_excon
end

#format_request(options) ⇒ String 



210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
 
# File 'lib/k8s/transport.rb', line 210

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) ⇒ Array<response_class, Hash, NilClass> 



362
363
364
365
 
# File 'lib/k8s/transport.rb', line 362

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

#gets(*paths, **options) ⇒ Array<response_class, Hash, NilClass> 



370
371
372
373
374
375
376
377
378
379
380
 
# File 'lib/k8s/transport.rb', line 370

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

#need_delete_body? ⇒ Boolean 



355
356
357
 
# File 'lib/k8s/transport.rb', line 355

def need_delete_body?
  @need_delete_body ||= Gem::Version.new(version.gitVersion.match(/^v*((\d|\.)*)/)[1]) < DELETE_OPTS_BODY_VERSION_MIN
end

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

Raises:



232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
 
# File 'lib/k8s/transport.rb', line 232

def parse_response(response, request_options, response_class: nil)
  method = request_options[:method]
  path = request_options[:path]
  content_type = response.headers['Content-Type']&.split(';', 2)&.first

  case content_type
  when 'application/json'
    response_data = Yajl::Parser.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'].inspect}")
  end

  if response.status.between? 200, 299
    return response_data if content_type == 'text/plain'

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

    return response_data unless response_class

    response_class.new(response_data)
  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(*parts) ⇒ String 



182
183
184
185
 
# File 'lib/k8s/transport.rb', line 182

def path(*parts)
  joined_parts = File.join(*parts)
  joined_parts.start_with?(path_prefix) ? joined_parts : File.join(path_prefix, joined_parts)
end

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



275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
 
# File 'lib/k8s/transport.rb', line 275

def request(response_class: nil, **options)
  if options[:method] == 'DELETE' && need_delete_body?
    options[:request_object] = options.delete(:query)
  end

  excon_options = request_options(**options)

  start = Time.now
  excon_client = options[:response_block] ? build_excon : excon
  response = excon_client.request(**excon_options)
  t = Time.now - start

  obj = options[:response_block] ? {} : parse_response(response, options, response_class: response_class)
rescue K8s::Error::API => e
  logger.warn { "#{format_request(options)} => HTTP #{e.code} #{e.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}" }
  obj
end

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



191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
 
# File 'lib/k8s/transport.rb', line 191

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

  if @auth_token
    options[:headers]['Authorization'] = "Bearer #{@auth_token}"
  elsif @auth_username && @auth_password
    options[:headers]['Authorization'] = "Basic #{Base64.strict_encode64("#{@auth_username}:#{@auth_password}")}"
  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, NilClass> 



306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
 
# File 'lib/k8s/transport.rb', line 306

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{ |opts| request_options(**common_options.merge(opts)) }
  )
  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
      raise unless skip_missing

      nil
    rescue K8s::Error::Forbidden
      raise unless skip_forbidden

      nil
    rescue K8s::Error::ServiceUnavailable => e
      raise unless retry_errors

      logger.warn { "Retry #{format_request(request_options)} => HTTP #{e.code} #{e.reason} in #{'%.3f' % t}s" }

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

#version ⇒ K8s::API::Version 



347
348
349
350
351
352
 
# File 'lib/k8s/transport.rb', line 347

def version
  @version ||= get(
    '/version',
    response_class: K8s::API::Version
  )
end