Rename Piwik to Matomo

See https://matomo.org/blog/2018/01/piwik-is-now-matomo/

changelogs/unreleased/rename-piwik-to-matomo.yml

+---
+title: Rename Piwik config items after rebranding to Matomo
+merge_request: 4667
+author: Katrin Leinweber @katrinleinweber
+type: changed

doc/.vale/gitlab/spelling-exceptions.txt

@@ -244,6 +244,7 @@ Makefile
 Makefiles
 Markdown
 markdownlint
+Matomo
 matcher
 matchers
 Mattermost

files/gitlab-config-template/gitlab.rb.template

@@ -595,8 +595,8 @@ external_url 'GENERATED_EXTERNAL_URL'
 ### Extra customization
 # gitlab_rails['extra_google_analytics_id'] = '_your_tracking_id'
-# gitlab_rails['extra_piwik_url'] = '_your_piwik_url'
-# gitlab_rails['extra_piwik_site_id'] = '_your_piwik_site_id'
+# gitlab_rails['extra_matomo_url'] = '_your_matomo_url'
+# gitlab_rails['extra_matomo_site_id'] = '_your_matomo_site_id'
 ##! Docs: https://docs.gitlab.com/omnibus/settings/environment-variables.html
 # gitlab_rails['env'] = {

files/gitlab-cookbooks/gitlab/attributes/default.rb

@@ -374,8 +374,8 @@ default['gitlab']['gitlab-rails']['gitlab_shell_git_timeout'] = 10800
 # defaults to /opt/gitlab/embedded/bin/git. The install-dir path is set at build time
 default['gitlab']['gitlab-rails']['git_bin_path'] = "#{node['package']['install-dir']}/embedded/bin/git"
 default['gitlab']['gitlab-rails']['extra_google_analytics_id'] = nil
-default['gitlab']['gitlab-rails']['extra_piwik_url'] = nil
-default['gitlab']['gitlab-rails']['extra_piwik_site_id'] = nil
+default['gitlab']['gitlab-rails']['extra_matomo_url'] = nil
+default['gitlab']['gitlab-rails']['extra_matomo_site_id'] = nil
 default['gitlab']['gitlab-rails']['rack_attack_git_basic_auth'] = nil
 default['gitlab']['gitlab-rails']['db_adapter'] = "postgresql"

files/gitlab-cookbooks/gitlab/templates/default/gitlab.yml.erb

@@ -859,10 +859,10 @@ production: &base
     google_analytics_id: <%= quote(@extra_google_analytics_id) %>
     <% end %>
-    <% if @extra_piwik_url %>
-    ## Piwik analytics.
-    piwik_url: <%= quote(@extra_piwik_url) %>
-    piwik_site_id: <%= quote(@extra_piwik_site_id) %>
+    <% if @extra_matomo_url %>
+    ## matomo analytics.
+    matomo_url: <%= quote(@extra_matomo_url) %>
+    matomo_site_id: <%= quote(@extra_matomo_site_id) %>
     <% end %>
   rack_attack: