gitlab: Organize place to keep parameters & their default imported from gitlab-omnibus

We will be using a several dozens of parameters to control gitlab
instance. It makes sense not to deviate in such parameters namings and
defaults from omnibus version.

Thus for such parameters - for clarity - we organize a separate file
where we will be keeping them - gitlab-parameters.cfg.

In this patch series all used parameters will be "imported" from
omnibus-gitlab 8.2.3+ce.0-0-g8eda093.

NOTE it is maybe better to try to autogenerate that file from upstream
    omnibus parameters definitions. If time will tell it becomes hard to
    maintain our copy - we'll consider going that way.

/cc @kazuhiko, @jerome

software/gitlab/gitlab-parameters.cfg

+# Upstream parameters for a GitLab instance
+#
+# Selected parameters - main ones - names and advanced defaults taken from omnibus-gitlab
+#   https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/files/gitlab-config-template/gitlab.rb.template
+#   https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/files/gitlab-cookbooks/gitlab/attributes/default.rb
+#
+# TODO better autogenerate from ^^^ (?)
+#
+# (last updated for omnibus-gitlab 8.2.3+ce.0-0-g8eda093)
+
+[gitlab-parameters]

software/gitlab/instance-gitlab.cfg.in

@@ -4,6 +4,7 @@
 #      security and performance reasons (unix has 2x less latency and more
 #      throughput compared to tcp over loopback).
 [buildout]
+extends = {{ gitlab_parameters_cfg }}
 parts =
     directory
 
@@ -41,6 +42,9 @@ url     = ${slap-connection:server-url}
 key     = ${slap-connection:key-file}
 cert    = ${slap-connection:cert-file}
 
+# autogenerated gitlab instance parameters
+<= gitlab-parameters
+
 
 
 #############################

software/gitlab/instance.cfg.in

@@ -38,6 +38,7 @@ context =
 # config files
     raw config_ru_in                ${config.ru.in:target}
     raw database_yml_in             ${database.yml.in:target}
+    raw gitlab_parameters_cfg       ${gitlab-parameters.cfg:target}
     raw gitlab_shell_config_yml_in  ${gitlab-shell-config.yml.in:target}
     raw gitlab_yml_in               ${gitlab.yml.in:target}
     raw rack_attack_rb_in           ${rack_attack.rb.in:target}

software/gitlab/software.cfg

@@ -192,6 +192,10 @@ url     = ${:_profile_base_location_}/template/${:_buildout_section_name_}
 <= download-template
 # md5sum = TODO
 
+[gitlab-parameters.cfg]
+<= download-file
+# md5sum = TODO
+
 [gitlab-shell-config.yml.in]
 <= download-template
 # md5sum = TODO