Custom Action support

lib/action.rb

+require_relative 'action/custom'
+
+module Action
+end

lib/action/custom.rb

+require 'base64'
+
+require_relative '../http_helper'
+
+module Action
+  class Custom
+    include HTTPHelper
+
+    class BaseError < StandardError; end
+    class MissingPayloadError < BaseError; end
+    class MissingAPIEndpointsError < BaseError; end
+    class MissingDataError < BaseError; end
+    class UnsuccessfulError < BaseError; end
+
+    NO_MESSAGE_TEXT = 'No message'.freeze
+    DEFAULT_HEADERS = { 'Content-Type' => 'application/json' }.freeze
+
+    def initialize(gl_id, payload)
+      @gl_id = gl_id
+      @payload = payload
+    end
+
+    def execute
+      validate!
+      result = process_api_endpoints
+
+      if result && HTTP_SUCCESS_CODES.include?(result.code)
+        result
+      else
+        raise_unsuccessful!(result)
+      end
+    end
+
+    private
+
+    attr_reader :gl_id, :payload
+
+    def process_api_endpoints
+      output = ''
+      resp = nil
+
+      data_with_gl_id = data.merge('gl_id' => gl_id)
+
+      api_endpoints.each do |endpoint|
+        url = "#{base_url}#{endpoint}"
+        json = { 'data' => data_with_gl_id, 'output' => output }
+
+        resp = post(url, {}, headers: DEFAULT_HEADERS, options: { json: json })
+        return resp unless HTTP_SUCCESS_CODES.include?(resp.code)
+
+        begin
+          body = JSON.parse(resp.body)
+        rescue JSON::ParserError
+          raise UnsuccessfulError, 'Response was not valid JSON'
+        end
+
+        print_flush(body['result'])
+
+        # In the context of the git push sequence of events, it's necessary to read
+        # stdin in order to capture output to pass onto subsequent commands
+        output = read_stdin
+      end
+
+      resp
+    end
+
+    def base_url
+      config.gitlab_url
+    end
+
+    def data
+      @data ||= payload['data']
+    end
+
+    def api_endpoints
+      data['api_endpoints']
+    end
+
+    def config
+      @config ||= GitlabConfig.new
+    end
+
+    def api
+      @api ||= GitlabNet.new
+    end
+
+    def read_stdin
+      Base64.encode64($stdin.read)
+    end
+
+    def print_flush(str)
+      return false unless str
+      print(Base64.decode64(str))
+      STDOUT.flush
+    end
+
+    def validate!
+      validate_payload!
+      validate_data!
+      validate_api_endpoints!
+    end
+
+    def validate_payload!
+      raise MissingPayloadError if !payload.is_a?(Hash) || payload.empty?
+    end
+
+    def validate_data!
+      raise MissingDataError unless data.is_a?(Hash)
+    end
+
+    def validate_api_endpoints!
+      raise MissingAPIEndpointsError if !api_endpoints.is_a?(Array) ||
+                                        api_endpoints.empty?
+    end
+
+    def raise_unsuccessful!(result)
+      message = begin
+        body = JSON.parse(result.body)
+        body['message'] || Base64.decode64(body['result']) || NO_MESSAGE_TEXT
+      rescue JSON::ParserError
+        NO_MESSAGE_TEXT
+      end
+
+      raise UnsuccessfulError, "#{message} (#{result.code})"
+    end
+  end
+end

lib/gitlab_access_status.rb

 require 'json'
+require_relative 'http_codes'
 
 class GitAccessStatus
-  attr_reader :message, :gl_repository, :gl_id, :gl_username, :gitaly, :git_protocol, :git_config_options
+  include HTTPCodes
 
-  def initialize(status, status_code, message, gl_repository: nil, gl_id: nil, gl_username: nil, gitaly: nil, git_protocol: nil, git_config_options: nil)
+  attr_reader :message, :gl_repository, :gl_id, :gl_username, :gitaly, :git_protocol, :git_config_options, :payload
+
+  def initialize(status, status_code, message, gl_repository: nil, gl_id: nil,
+                 gl_username: nil, gitaly: nil, git_protocol: nil,
+                 git_config_options: nil, payload: nil)
     @status = status
     @status_code = status_code
     @message = message
@@ -13,6 +18,7 @@ class GitAccessStatus
     @git_config_options = git_config_options
     @gitaly = gitaly
     @git_protocol = git_protocol
+    @payload = payload
   end
 
   def self.create_from_json(json, status_code)
@@ -25,10 +31,15 @@ class GitAccessStatus
         gl_username: values["gl_username"],
         git_config_options: values["git_config_options"],
         gitaly: values["gitaly"],
-        git_protocol: values["git_protocol"])
+        git_protocol: values["git_protocol"],
+        payload: values["payload"])
   end
 
   def allowed?
     @status
   end
+
+  def custom_action?
+    @status_code == HTTP_MULTIPLE_CHOICES
+  end
 end

lib/gitlab_net.rb

@@ -33,9 +33,9 @@ class GitlabNet # rubocop:disable Metrics/ClassLength
     url = "#{internal_api_endpoint}/allowed"
     resp = post(url, params)
 
-    case resp.code.to_s
-    when HTTP_SUCCESS, HTTP_UNAUTHORIZED, HTTP_NOT_FOUND
-      GitAccessStatus.create_from_json(resp.body)
+    case resp.code
+    when HTTP_SUCCESS, HTTP_MULTIPLE_CHOICES, HTTP_UNAUTHORIZED, HTTP_NOT_FOUND
+      GitAccessStatus.create_from_json(resp.body, resp.code)
     else
       GitAccessStatus.new(false, resp.code, 'API is not accessible')
     end

lib/gitlab_shell.rb

@@ -5,6 +5,7 @@ require 'pathname'
 
 require_relative 'gitlab_net'
 require_relative 'gitlab_metrics'
+require_relative 'action'
 
 class GitlabShell # rubocop:disable Metrics/ClassLength
   class AccessDeniedError < StandardError; end
@@ -50,8 +51,17 @@ class GitlabShell # rubocop:disable Metrics/ClassLength
     args = Shellwords.shellwords(origin_cmd)
     args = parse_cmd(args)
 
+    access_status = nil
+
     if GIT_COMMANDS.include?(args.first)
-      GitlabMetrics.measure('verify-access') { verify_access }
+      access_status = GitlabMetrics.measure('verify-access') { verify_access }
+
+      @gl_repository = access_status.gl_repository
+      @git_protocol = ENV['GIT_PROTOCOL']
+      @gitaly = access_status.gitaly
+      @username = access_status.gl_username
+      @git_config_options = access_status.git_config_options
+      @gl_id = access_status.gl_id if defined?(@who)
     elsif !defined?(@gl_id)
       # We're processing an API command like 2fa_recovery_codes, but
       # don't have a @gl_id yet, that means we're in the "username"
@@ -60,6 +70,13 @@ class GitlabShell # rubocop:disable Metrics/ClassLength
       user
     end
 
+    if @command == GIT_RECEIVE_PACK_COMMAND && access_status.custom_action?
+      # If the response from /api/v4/allowed is a HTTP 300, we need to perform
+      # a Custom Action and therefore should return and not call process_cmd()
+      #
+      return process_custom_action(access_status)
+    end
+
     process_cmd(args)
 
     true
@@ -68,17 +85,19 @@ class GitlabShell # rubocop:disable Metrics/ClassLength
     false
   rescue AccessDeniedError => ex
     $logger.warn('Access denied', command: origin_cmd, user: log_username)
-
     $stderr.puts "GitLab: #{ex.message}"
     false
   rescue DisallowedCommandError
     $logger.warn('Denied disallowed command', command: origin_cmd, user: log_username)
-
     $stderr.puts "GitLab: Disallowed command"
     false
   rescue InvalidRepositoryPathError
     $stderr.puts "GitLab: Invalid repository path"
     false
+  rescue Action::Custom::BaseError => ex
+    $logger.warn('Custom action error', command: origin_cmd, user: log_username)
+    $stderr.puts "GitLab: #{ex.message}"
+    false
   end
 
   protected
@@ -123,14 +142,11 @@ class GitlabShell # rubocop:disable Metrics/ClassLength
 
     raise AccessDeniedError, status.message unless status.allowed?
 
-    @gl_repository = status.gl_repository
-    @git_protocol = ENV['GIT_PROTOCOL']
-    @gitaly = status.gitaly
-    @username = status.gl_username
-    @git_config_options = status.git_config_options
-    if defined?(@who)
-      @gl_id = status.gl_id
-    end
+    status
+  end
+
+  def process_custom_action(access_status)
+    Action::Custom.new(@gl_id, access_status.payload).execute
   end
 
   def process_cmd(args)

spec/action/custom_spec.rb

+require_relative '../spec_helper'
+require_relative '../../lib/action/custom'
+
+describe Action::Custom do
+  let(:repo_name) { 'gitlab-ci.git' }
+  let(:gl_id) { 'key-1' }
+  let(:secret) { "0a3938d9d95d807e94d937af3a4fbbea" }
+  let(:base_url) { 'http://localhost:3000' }
+
+  subject { described_class.new(gl_id, payload) }
+
+  describe '#execute' do
+    context 'with an empty payload' do
+      let(:payload) { {} }
+
+      it 'raises a MissingPayloadError exception' do
+        expect { subject.execute }.to raise_error(Action::Custom::MissingPayloadError)
+      end
+    end
+
+    context 'with api_endpoints defined' do
+      before do
+        allow(subject).to receive(:base_url).and_return(base_url)
+        allow(subject).to receive(:secret_token).and_return(secret)
+        allow($stdin).to receive(:read).and_return('')
+      end
+
+      context 'that are valid' do
+        let(:payload) do
+          {
+            'action' => 'geo_proxy_to_primary',
+            'data' => {
+              'api_endpoints' => %w{/api/v4/fake/info_refs /api/v4/fake/push},
+              'gl_username' => 'user1',
+              'primary_repo' => 'http://localhost:3001/user1/repo1.git'
+            }
+          }
+        end
+
+        context 'and responds correctly' do
+          it 'returns an instance of Net::HTTPCreated' do
+            VCR.use_cassette("custom-action-ok") do
+              expect(subject.execute).to be_instance_of(Net::HTTPCreated)
+            end
+          end
+        end
+
+        context 'but responds incorrectly' do
+          it 'raises an UnsuccessfulError exception' do
+            VCR.use_cassette("custom-action-ok-not-json") do
+              expect {
+                subject.execute
+              }.to raise_error(Action::Custom::UnsuccessfulError, 'Response was not valid JSON')
+            end
+          end
+        end
+      end
+
+      context 'that are invalid' do
+        context 'where api_endpoints gl_id is missing' do
+          let(:payload) do
+            {
+              'action' => 'geo_proxy_to_primary',
+              'data' => {
+                'gl_username' => 'user1',
+                'primary_repo' => 'http://localhost:3001/user1/repo1.git'
+              }
+            }
+          end
+
+          it 'raises a MissingAPIEndpointsError exception' do
+            expect { subject.execute }.to raise_error(Action::Custom::MissingAPIEndpointsError)
+          end
+        end
+
+        context 'where api_endpoints are empty' do
+          let(:payload) do
+            {
+              'action' => 'geo_proxy_to_primary',
+              'data' => {
+                'api_endpoints' => [],
+                'gl_username' => 'user1',
+                'primary_repo' => 'http://localhost:3001/user1/repo1.git'
+              }
+            }
+          end
+
+          it 'raises a MissingAPIEndpointsError exception' do
+            expect { subject.execute }.to raise_error(Action::Custom::MissingAPIEndpointsError)
+          end
+        end
+
+        context 'where data gl_id is missing' do
+          let(:payload) { { 'api_endpoints' => %w{/api/v4/fake/info_refs /api/v4/fake/push} } }
+
+          it 'raises a MissingDataError exception' do
+            expect { subject.execute }.to raise_error(Action::Custom::MissingDataError)
+          end
+        end
+
+        context 'where API endpoints are bad' do
+          let(:payload) do
+            {
+              'action' => 'geo_proxy_to_primary',
+              'data' => {
+                'api_endpoints' => %w{/api/v4/fake/info_refs_bad /api/v4/fake/push_bad},
+                'gl_username' => 'user1',
+                'primary_repo' => 'http://localhost:3001/user1/repo1.git'
+              }
+            }
+          end
+
+          context 'and response is JSON' do
+            it 'raises an UnsuccessfulError exception' do
+              VCR.use_cassette("custom-action-not-ok-json") do
+                expect {
+                  subject.execute
+                }.to raise_error(Action::Custom::UnsuccessfulError, 'You cannot perform write operations on a read-only instance (403)')
+              end
+            end
+          end
+
+          context 'and response is not JSON' do
+            it 'raises an UnsuccessfulError exception' do
+              VCR.use_cassette("custom-action-not-ok-not-json") do
+                expect {
+                  subject.execute
+                }.to raise_error(Action::Custom::UnsuccessfulError, 'No message (403)')
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/gitlab_shell_spec.rb

@@ -256,6 +256,29 @@ describe GitlabShell do
         user_string = "user with id #{gl_id}"
         expect($logger).to receive(:info).with(message, command: "gitaly-receive-pack unix:gitaly.socket #{gitaly_message}", user: user_string)
       end
+
+      context 'with a custom action' do
+        let(:fake_payload) { { 'api_endpoints' => [ '/fake/api/endpoint' ], 'data' => {} } }
+        let(:custom_action_gitlab_access_status) do
+          GitAccessStatus.new(
+            true,
+            HTTPCodes::HTTP_MULTIPLE_CHOICES,
+            'Multiple Choices',
+            payload: fake_payload
+          )
+        end
+        let(:action_custom) { double(Action::Custom) }
+
+        before do
+          allow(api).to receive(:check_access).and_return(custom_action_gitlab_access_status)
+        end
+
+        it "should not process the command" do
+          expect(subject).to_not receive(:process_cmd).with(%w(git-receive-pack gitlab-ci.git))
+          expect(Action::Custom).to receive(:new).with(gl_id, fake_payload).and_return(action_custom)
+          expect(action_custom).to receive(:execute)
+        end
+      end
     end
 
     context 'gitaly-receive-pack' do

spec/vcr_cassettes/custom-action-not-ok-json.yml

+---
+http_interactions:
+- request:
+    method: post
+    uri: http://localhost:3000/api/v4/fake/info_refs_bad
+    body:
+      encoding: UTF-8
+      string: '{"data":{"gl_username":"user1","primary_repo":"http://localhost:3001/user1/repo1.git","gl_id":"key-11"},"output":"","secret_token":"0a3938d9d95d807e94d937af3a4fbbea\n"}'
+    headers:
+      Content-Type:
+      - application/json
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+      User-Agent:
+      - Ruby
+      Host:
+      - localhost
+  response:
+    status:
+      code: 403
+      message: Forbidden
+    headers:
+      Date:
+      - Fri, 20 Jul 2018 06:54:21 GMT
+      Connection:
+      - close
+      Content-Type:
+      - application/json
+      X-Request-Id:
+      - ea0644ac-e1ad-45f6-aa72-cc7910274318
+      X-Runtime:
+      - '1.236672'
+    body:
+      encoding: UTF-8
+      string: '{"message":"You cannot perform write operations on a read-only instance"}'
+    http_version:
+  recorded_at: Fri, 20 Jul 2018 06:54:21 GMT
+recorded_with: VCR 2.4.0

spec/vcr_cassettes/custom-action-not-ok-not-json.yml

+---
+http_interactions:
+- request:
+    method: post
+    uri: http://localhost:3000/api/v4/fake/info_refs_bad
+    body:
+      encoding: UTF-8
+      string: '{"data":{"gl_username":"user1","primary_repo":"http://localhost:3001/user1/repo1.git","gl_id":"key-11"},"output":"","secret_token":"0a3938d9d95d807e94d937af3a4fbbea\n"}'
+    headers:
+      Content-Type:
+      - application/json
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+      User-Agent:
+      - Ruby
+      Host:
+      - localhost
+  response:
+    status:
+      code: 403
+      message: Forbidden
+    headers:
+      Date:
+      - Fri, 20 Jul 2018 06:54:21 GMT
+      Connection:
+      - close
+      Content-Type:
+      - application/json
+      X-Request-Id:
+      - ea0644ac-e1ad-45f6-aa72-cc7910274318
+      X-Runtime:
+      - '1.236672'
+    body:
+      encoding: UTF-8
+      string: '""'
+    http_version:
+  recorded_at: Fri, 20 Jul 2018 06:54:21 GMT
+recorded_with: VCR 2.4.0

spec/vcr_cassettes/custom-action-ok-not-json.yml

+---
+http_interactions:
+- request:
+    method: post
+    uri: http://localhost:3000/api/v4/fake/info_refs
+    body:
+      encoding: UTF-8
+      string: '{"data":{"gl_username":"user1","primary_repo":"http://localhost:3001/user1/repo1.git","gl_id":"key-1"},"output":"","secret_token":"0a3938d9d95d807e94d937af3a4fbbea"}'
+    headers:
+      Content-Type:
+      - application/json
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+      User-Agent:
+      - Ruby
+      Host:
+      - localhost
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Fri, 20 Jul 2018 06:18:58 GMT
+      Connection:
+      - close
+      X-Frame-Options:
+      - SAMEORIGIN
+      X-Content-Type-Options:
+      - nosniff
+      Content-Type:
+      - application/json
+      Content-Length:
+      - '172'
+      Vary:
+      - Origin
+      Etag:
+      - W/"7d01e1e3dbcbe7cca9607461352f8244"
+      Cache-Control:
+      - max-age=0, private, must-revalidate
+      X-Request-Id:
+      - 03afa234-b6be-49ab-9392-4aa35c5dee25
+      X-Runtime:
+      - '1.436040'
+    body:
+      encoding: UTF-8
+      string: '""'
+    http_version:
+  recorded_at: Fri, 20 Jul 2018 06:18:58 GMT

spec/vcr_cassettes/custom-action-ok.yml

+---
+http_interactions:
+- request:
+    method: post
+    uri: http://localhost:3000/api/v4/fake/info_refs
+    body:
+      encoding: UTF-8
+      string: '{"data":{"gl_username":"user1","primary_repo":"http://localhost:3001/user1/repo1.git","gl_id":"key-1"},"output":"","secret_token":"0a3938d9d95d807e94d937af3a4fbbea"}'
+    headers:
+      Content-Type:
+      - application/json
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+      User-Agent:
+      - Ruby
+      Host:
+      - localhost
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Fri, 20 Jul 2018 06:18:58 GMT
+      Connection:
+      - close
+      X-Frame-Options:
+      - SAMEORIGIN
+      X-Content-Type-Options:
+      - nosniff
+      Content-Type:
+      - application/json
+      Content-Length:
+      - '172'
+      Vary:
+      - Origin
+      Etag:
+      - W/"7d01e1e3dbcbe7cca9607461352f8244"
+      Cache-Control:
+      - max-age=0, private, must-revalidate
+      X-Request-Id:
+      - 03afa234-b6be-49ab-9392-4aa35c5dee25
+      X-Runtime:
+      - '1.436040'
+    body:
+      encoding: UTF-8
+      string: '{"result":"info_refs-result"}'
+    http_version:
+  recorded_at: Fri, 20 Jul 2018 06:18:58 GMT
+- request:
+    method: post
+    uri: http://localhost:3000/api/v4/fake/push
+    body:
+      encoding: UTF-8
+      string: '{"data":{"gl_username":"user1","primary_repo":"http://localhost:3001/user1/repo1.git","gl_id":"key-1"},"output":"info_refs-result","secret_token":"0a3938d9d95d807e94d937af3a4fbbea"}'
+    headers:
+      Content-Type:
+      - application/json
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+      User-Agent:
+      - Ruby
+      Host:
+      - localhost
+  response:
+    status:
+      code: 201
+      message: Created
+    headers:
+      Date:
+      - Fri, 20 Jul 2018 06:19:08 GMT
+      Connection:
+      - close
+      X-Frame-Options:
+      - SAMEORIGIN
+      X-Content-Type-Options:
+      - nosniff
+      Content-Type:
+      - application/json
+      Content-Length:
+      - '13'
+      Vary:
+      - Origin
+      Cache-Control:
+      - no-cache
+      X-Request-Id:
+      - 0c6894ac-7f8e-4cdb-871f-4cb64d3731ca
+      X-Runtime:
+      - '0.786754'
+    body:
+      encoding: UTF-8
+      string: '{"result":"push-result"}'
+    http_version:
+  recorded_at: Fri, 20 Jul 2018 06:19:08 GMT
+recorded_with: VCR 2.4.0