Class: Aspera::Rest

Inherits:
Object
  • Object
show all
Defined in:
lib/aspera/rest.rb

Overview

a simple class to make HTTP calls, equivalent to rest-client rest call errors are raised as exception RestCallError and error are analyzed in RestErrorAnalyzer

Direct Known Subclasses

AoC, AtsApi, Node

Constant Summary collapse

ENTITY_NOT_FOUND =

error message when entity not found

'No such'
@@global =

global settings also valid for any subclass

{ # rubocop:disable Style/ClassVars
  debug:                   false,
  # true if https ignore certificate
  user_agent:              'Ruby',
  download_partial_suffix: '.http_partial',
  # a lambda which takes the Net::HTTP as arg, use this to change parameters
  session_cb:              nil,
  proxy_user:              nil,
  proxy_pass:              nil
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(a_rest_params) ⇒ Rest

Returns a new instance of Rest.

Parameters:

  • default call parameters (merged at call)



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# File 'lib/aspera/rest.rb', line 130

def initialize(a_rest_params)
  raise 'ERROR: expecting Hash' unless a_rest_params.is_a?(Hash)
  raise 'ERROR: expecting base_url' unless a_rest_params[:base_url].is_a?(String)
  @params = a_rest_params.clone
  Log.dump('REST params', @params)
  # base url without trailing slashes (note: string may be frozen)
  @params[:base_url] = @params[:base_url].gsub(%r{/+$}, '')
  @http_session = nil
  # default is no auth
  @params[:auth] ||= {type: :none}
  @params[:not_auth_codes] ||= ['401']
  @oauth = nil
  Log.dump('REST params(2)', @params)
end

Instance Attribute Details

#params ⇒ Object (readonly)

Returns the value of attribute params.



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# File 'lib/aspera/rest.rb', line 119

def params
  @params
end

Class Method Details

.array_params(values) ⇒ Object

used to build a parameter list prefixed with “[]”

Parameters:

  • list of values



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# File 'lib/aspera/rest.rb', line 60

def array_params(values)
  return [ARRAY_PARAMS].concat(values)
end

.basic_creds(user, pass) ⇒ Object 



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# File 'lib/aspera/rest.rb', line 56

def basic_creds(user, pass); return "Basic #{Base64.strict_encode64("#{user}:#{pass}")}"; end

.build_uri(url, params = nil) ⇒ Object

build URI from URL and parameters and check it is http or https



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# File 'lib/aspera/rest.rb', line 65

def build_uri(url, params=nil)
  uri = URI.parse(url)
  raise "REST endpoint shall be http/s not #{uri.scheme}" unless %w[http https].include?(uri.scheme)
  if !params.nil?
    # support array url params, there is no standard. Either p[]=1&p[]=2, or p=1&p=2
    if params.is_a?(Hash)
      orig = params
      params = []
      orig.each do |k, v|
        case v
        when Array
          suffix = v.first.eql?(ARRAY_PARAMS) ? v.shift : ''
          v.each do |e|
            params.push([k.to_s + suffix, e])
          end
        else
          params.push([k, v])
        end
      end
    end
    # CGI.unescape to transform back %5D into []
    uri.query = CGI.unescape(URI.encode_www_form(params))
  end
  return uri
end

.start_http_session(base_url) ⇒ Object 



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# File 'lib/aspera/rest.rb', line 91

def start_http_session(base_url)
  uri = build_uri(base_url)
  # this honors http_proxy env var
  http_session = Net::HTTP.new(uri.host, uri.port)
  http_session.proxy_user = proxy_user
  http_session.proxy_pass = proxy_pass
  http_session.use_ssl = uri.scheme.eql?('https')
  http_session.set_debug_output($stdout) if debug
  # set http options in callback, such as timeout and cert. verification
  session_cb&.call(http_session)
  # manually start session for keep alive (if supported by server, else, session is closed every time)
  http_session.start
  return http_session
end

Instance Method Details

#build_request(call_data) ⇒ Object 



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# File 'lib/aspera/rest.rb', line 150

def build_request(call_data)
  # TODO: shall we percent encode subpath (spaces) test with access key delete with space in id
  # URI.escape()
  uri = self.class.build_uri("#{call_data[:base_url]}#{['', '/'].include?(call_data[:subpath]) ? '' : '/'}#{call_data[:subpath]}", call_data[:url_params])
  Log.log.debug{"URI=#{uri}"}
  begin
    # instantiate request object based on string name
    req = Net::HTTP.const_get(call_data[:operation].capitalize).new(uri)
  rescue NameError
    raise "unsupported operation : #{call_data[:operation]}"
  end
  if call_data.key?(:json_params) && !call_data[:json_params].nil?
    req.body = JSON.generate(call_data[:json_params])
    Log.dump('body JSON data', call_data[:json_params])
    req['Content-Type'] = 'application/json'
    # call_data[:headers]['Accept']='application/json'
  end
  if call_data.key?(:www_body_params)
    req.body = URI.encode_www_form(call_data[:www_body_params])
    Log.log.debug{"body www data=#{req.body.chomp}"}
    req['Content-Type'] = 'application/x-www-form-urlencoded'
  end
  if call_data.key?(:text_body_params)
    req.body = call_data[:text_body_params]
    Log.log.debug{"body data=#{req.body.chomp}"}
  end
  # set headers
  if call_data.key?(:headers)
    call_data[:headers].each_key do |key|
      req[key] = call_data[:headers][key]
    end
  end
  # :type = :basic
  req.basic_auth(call_data[:auth][:username], call_data[:auth][:password]) if call_data[:auth][:type].eql?(:basic)
  return req
end

#call(call_data) ⇒ Object

HTTP/S REST call call_data has keys: :auth :operation :subpath :headers :json_params :url_params :www_body_params :text_body_params :save_to_file (filepath) default: nil :return_error (bool) default: nil :redirect_max (int) default: 0 :not_auth_codes (array) codes that trigger a refresh/regeneration of bearer token

authentication (:auth) : :type (:none, :basic, :oauth2, :url) :username [:basic] :password [:basic] :url_creds [:url] a hash :* [:oauth2] see Oauth class



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# File 'lib/aspera/rest.rb', line 208

def call(call_data)
  raise "Hash call parameter is required (#{call_data.class})" unless call_data.is_a?(Hash)
  call_data[:subpath] = '' if call_data[:subpath].nil?
  Log.log.debug{"accessing #{call_data[:subpath]}".red.bold.bg_green}
  call_data[:headers] ||= {}
  call_data[:headers]['User-Agent'] ||= self.class.user_agent
  # defaults from @params are overridden by call data
  call_data = @params.deep_merge(call_data)
  case call_data[:auth][:type]
  when :none
    # no auth
  when :basic
    Log.log.debug('using Basic auth')
    # done in build_req
  when :oauth2
    call_data[:headers]['Authorization'] = oauth_token unless call_data[:headers].key?('Authorization')
  when :url
    call_data[:url_params] ||= {}
    call_data[:auth][:url_creds].each do |key, value|
      call_data[:url_params][key] = value
    end
  else raise "unsupported auth type: [#{call_data[:auth][:type]}]"
  end
  req = build_request(call_data)
  Log.log.debug{"call_data = #{call_data}"}
  result = {http: nil}
  # start a block to be able to retry the actual HTTP request
  begin
    # we try the call, and will retry only if oauth, as we can, first with refresh, and then re-auth if refresh is bad
    oauth_tries ||= 2
    # initialize with number of initial retries allowed, nil gives zero
    tries_remain_redirect = call_data[:redirect_max].to_i if tries_remain_redirect.nil?
    Log.log.debug("send request (retries=#{tries_remain_redirect})")
    # make http request (pipelined)
    http_session.request(req) do |response|
      result[:http] = response
      if !call_data[:save_to_file].nil? && result[:http].code.to_s.start_with?('2')
        total_size = result[:http]['Content-Length'].to_i
        progress = ProgressBar.create(
          format:     '%a %B %p%% %r KB/sec %e',
          rate_scale: lambda{|rate|rate / 1024},
          title:      'progress',
          total:      total_size)
        Log.log.debug('before write file')
        target_file = call_data[:save_to_file]
        # override user's path to path in header
        if !response['Content-Disposition'].nil? && (m = response['Content-Disposition'].match(/filename="([^"]+)"/))
          target_file = File.join(File.dirname(target_file), m[1])
        end
        # download with temp filename
        target_file_tmp = "#{target_file}#{self.class.download_partial_suffix}"
        Log.log.debug{"saving to: #{target_file}"}
        File.open(target_file_tmp, 'wb') do |file|
          result[:http].read_body do |fragment|
            file.write(fragment)
            new_process = progress.progress + fragment.length
            new_process = total_size if new_process > total_size
            progress.progress = new_process
          end
        end
        # rename at the end
        File.rename(target_file_tmp, target_file)
        progress = nil
      end # save_to_file
    end
    # sometimes there is a UTF8 char (e.g. (c) )
    result[:http].body.force_encoding('UTF-8') if result[:http].body.is_a?(String)
    Log.log.debug{"result: body=#{result[:http].body}"}
    result_mime = (result[:http]['Content-Type'] || 'text/plain').split(';').first
    result[:data] = case result_mime
    when 'application/json', 'application/vnd.api+json'
      JSON.parse(result[:http].body) rescue nil
    else # when 'text/plain'
      result[:http].body
    end
    Log.dump("result: parsed: #{result_mime}", result[:data])
    Log.log.debug{"result: code=#{result[:http].code}"}
    RestErrorAnalyzer.instance.raise_on_error(req, result)
  rescue RestCallError => e
    # not authorized: oauth token expired
    if call_data[:not_auth_codes].include?(result[:http].code.to_s) && call_data[:auth][:type].eql?(:oauth2)
      begin
        # try to use refresh token
        req['Authorization'] = oauth_token(force_refresh: true)
      rescue RestCallError => e_tok
        e = e_tok
        Log.log.error('refresh failed'.bg_red)
        # regenerate a brand new token
        req['Authorization'] = oauth_token(force_refresh: true)
      end
      Log.log.debug{"using new token=#{call_data[:headers]['Authorization']}"}
      retry unless (oauth_tries -= 1).zero?
    end # if oauth
    # redirect ? (any code beginning with 3)
    if tries_remain_redirect.positive? && e.response.is_a?(Net::HTTPRedirection)
      tries_remain_redirect -= 1
      current_uri = URI.parse(call_data[:base_url])
      new_url = e.response['location']
      new_url = "#{current_uri.scheme}:#{new_url}" unless new_url.start_with?('http')
      Log.log.info{"URL is moved: #{new_url}"}
      redirection_uri = URI.parse(new_url)
      call_data[:base_url] = new_url
      call_data[:subpath] = ''
      if current_uri.host.eql?(redirection_uri.host) && current_uri.port.eql?(redirection_uri.port)
        req = build_request(call_data)
        retry
      else
        # change host
        Log.log.info{"Redirect changes host: #{current_uri.host} -> #{redirection_uri.host}"}
        return self.class.new(call_data).call(call_data)
      end
    end
    # raise exception if could not retry and not return error in result
    raise e unless call_data[:return_error]
  end # begin request
  Log.log.debug{"result=#{result}"}
  return result
end

#cancel(subpath) ⇒ Object 



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# File 'lib/aspera/rest.rb', line 348

def cancel(subpath)
  return call({operation: 'CANCEL', subpath: subpath, headers: {'Accept' => 'application/json'}})
end

#create(subpath, params, encoding = :json_params) ⇒ Object

Parameters:

  • (defaults to: :json_params)

    : one of: :json_params, :url_params



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# File 'lib/aspera/rest.rb', line 332

def create(subpath, params, encoding=:json_params)
  return call({operation: 'POST', subpath: subpath, headers: {'Accept' => 'application/json'}, encoding => params})
end

#delete(subpath, args = nil) ⇒ Object 



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# File 'lib/aspera/rest.rb', line 344

def delete(subpath, args=nil)
  return call({operation: 'DELETE', subpath: subpath, headers: {'Accept' => 'application/json'}, url_params: args})
end

#lookup_by_name(subpath, search_name, options = {}) ⇒ Object

Query by name and returns a single result, else it throws an exception (no or multiple results)

Parameters:

  • path of entity in API

  • name of searched entity

  • (defaults to: {})

    additional search options



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# File 'lib/aspera/rest.rb', line 356

def lookup_by_name(subpath, search_name, options={})
  # returns entities whose name contains value (case insensitive)
  matching_items = read(subpath, options.merge({'q' => CGI.escape(search_name)}))[:data]
  # API style: {totalcount:, ...} cspell: disable-line
  # TODO: not generic enough ? move somewhere ? inheritance ?
  matching_items = matching_items[subpath] if matching_items.is_a?(Hash)
  raise "Internal error: expecting array, have #{matching_items.class}" unless matching_items.is_a?(Array)
  case matching_items.length
  when 1 then return matching_items.first
  when 0 then raise %Q{#{ENTITY_NOT_FOUND} #{subpath}: "#{search_name}"}
  else
    # multiple case insensitive partial matches, try case insensitive full match
    # (anyway AoC does not allow creation of 2 entities with same case insensitive name)
    name_matches = matching_items.select{|i|i['name'].casecmp?(search_name)}
    case name_matches.length
    when 1 then return name_matches.first
    when 0 then raise %Q(#{subpath}: multiple case insensitive partial match for: "#{search_name}": #{matching_items.map{|i|i['name']}} but no case insensitive full match. Please be more specific or give exact name.) # rubocop:disable Layout/LineLength
    else raise "Two entities cannot have the same case insensitive name: #{name_matches.map{|i|i['name']}}"
    end
  end
end

#oauth ⇒ Object 



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# File 'lib/aspera/rest.rb', line 121

def oauth
  if @oauth.nil?
    raise 'ERROR: no OAuth defined' unless @params[:auth][:type].eql?(:oauth2)
    @oauth = Oauth.new(@params[:auth])
  end
  return @oauth
end

#oauth_token(force_refresh: false) ⇒ Object 



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# File 'lib/aspera/rest.rb', line 145

def oauth_token(force_refresh: false)
  raise "ERROR: expecting boolean, have #{force_refresh}" unless [true, false].include?(force_refresh)
  return oauth.get_authorization(use_refresh_token: force_refresh)
end

#read(subpath, args = nil) ⇒ Object 



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# File 'lib/aspera/rest.rb', line 336

def read(subpath, args=nil)
  return call({operation: 'GET', subpath: subpath, headers: {'Accept' => 'application/json'}, url_params: args})
end

#update(subpath, params) ⇒ Object 



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# File 'lib/aspera/rest.rb', line 340

def update(subpath, params)
  return call({operation: 'PUT', subpath: subpath, headers: {'Accept' => 'application/json'}, json_params: params})
end