Add CI variable to provide GitLab FQDN

Signed-off-by: Balasankar "Balu" C <balasankar@gitlab.com>

app/models/concerns/ci/contextable.rb

@@ -59,6 +59,7 @@ module Ci
         variables.append(key: 'CI', value: 'true')
         variables.append(key: 'GITLAB_CI', value: 'true')
         variables.append(key: 'GITLAB_FEATURES', value: project.licensed_features.join(','))
+        variables.append(key: 'CI_SERVER_HOST', value: Gitlab.config.gitlab.host)
         variables.append(key: 'CI_SERVER_NAME', value: 'GitLab')
         variables.append(key: 'CI_SERVER_VERSION', value: Gitlab::VERSION)
         variables.append(key: 'CI_SERVER_VERSION_MAJOR', value: Gitlab.version_info.major.to_s)

changelogs/unreleased/64161-gitlab-fqdn.yml

+---
+title: Add CI variable to provide GitLab HOST
+merge_request: 30417
+author:
+type: added

spec/models/ci/build_spec.rb

@@ -2013,6 +2013,7 @@ describe Ci::Build do
           { key: 'CI', value: 'true', public: true, masked: false },
           { key: 'GITLAB_CI', value: 'true', public: true, masked: false },
           { key: 'GITLAB_FEATURES', value: project.licensed_features.join(','), public: true, masked: false },
+          { key: 'CI_SERVER_HOST', value: Gitlab.config.gitlab.host, public: true, masked: false },
           { key: 'CI_SERVER_NAME', value: 'GitLab', public: true, masked: false },
           { key: 'CI_SERVER_VERSION', value: Gitlab::VERSION, public: true, masked: false },
           { key: 'CI_SERVER_VERSION_MAJOR', value: Gitlab.version_info.major.to_s, public: true, masked: false },