Fix Bamboo CI status not showing for branch plans

The original API that queries by label (`/rest/api/latest/result?label=#{sha1}`)
only works for results from main plans and not branch plans. The
`/rest/api/latest/result/byChangeset/#{sha1}` endpoint gives results from
branch plans but not for the first push to the branch. Subsequent pushes
work.

For more details, see https://jira.atlassian.com/browse/BAM-16121.

Closes #1355

app/models/project_services/bamboo_service.rb

@@ -67,11 +67,11 @@ class BambooService < CiService
   def execute(data)
     return unless supported_events.include?(data[:object_kind])
 
-    get_path("updateAndBuild.action?buildKey=#{build_key}")
+    get_path("updateAndBuild.action", { buildKey: build_key })
   end
 
   def calculate_reactive_cache(sha, ref)
-    response = get_path("rest/api/latest/result?label=#{sha}")
+    response = get_path("rest/api/latest/result/byChangeset/#{sha}")
 
     { build_page: read_build_page(response), commit_status: read_commit_status(response) }
   end
@@ -113,14 +113,16 @@ class BambooService < CiService
     URI.join("#{bamboo_url}/", path).to_s
   end
 
-  def get_path(path)
+  def get_path(path, query_params = {})
     url = build_url(path)
 
     if username.blank? && password.blank?
-      Gitlab::HTTP.get(url, verify: false)
+      Gitlab::HTTP.get(url, verify: false, query: query_params)
     else
-      url << '&os_authType=basic'
-      Gitlab::HTTP.get(url, verify: false,
+      query_params[:os_authType] = 'basic'
+      Gitlab::HTTP.get(url,
+                       verify: false,
+                       query: query_params,
                        basic_auth: {
                          username: username,
                          password: password

changelogs/unreleased/sh-fix-bamboo-change-set.yml

+---
+title: Fix Bamboo CI status not showing for branch plans
+merge_request:
+author:
+type: fixed

spec/models/project_services/bamboo_service_spec.rb

@@ -120,6 +120,14 @@ describe BambooService, :use_clean_rails_memory_store_caching do
     end
   end
 
+  describe '#execute' do
+    it 'runs update and build action' do
+      stub_update_and_build_request
+
+      subject.execute(Gitlab::DataBuilder::Push::SAMPLE_DATA)
+    end
+  end
+
   describe '#build_page' do
     it 'returns the contents of the reactive cache' do
       stub_reactive_cache(service, { build_page: 'foo' }, 'sha', 'ref')
@@ -216,10 +224,20 @@ describe BambooService, :use_clean_rails_memory_store_caching do
     end
   end
 
+  def stub_update_and_build_request(status: 200, body: nil)
+    bamboo_full_url = 'http://gitlab.com/bamboo/updateAndBuild.action?buildKey=foo&os_authType=basic'
+
+    stub_bamboo_request(bamboo_full_url, status, body)
+  end
+
   def stub_request(status: 200, body: nil)
-    bamboo_full_url = 'http://gitlab.com/bamboo/rest/api/latest/result?label=123&os_authType=basic'
+    bamboo_full_url = 'http://gitlab.com/bamboo/rest/api/latest/result/byChangeset/123?os_authType=basic'
+
+    stub_bamboo_request(bamboo_full_url, status, body)
+  end
 
-    WebMock.stub_request(:get, bamboo_full_url).to_return(
+  def stub_bamboo_request(url, status, body)
+    WebMock.stub_request(:get, url).to_return(
       status: status,
       headers: { 'Content-Type' => 'application/json' },
       body: body