Don't allow usernames to clash with teams

Up until now we allowed users to have the same username as some teams. This is
troublesome because then the private team assigned to this user would clash
with the existing one.

In the future we should figure out a way to better handle these hidden teams
(e.g. by creating one with a random name and the reference it on the user row).
For now, in order to not be too disruptive we will disallow creating users with
the same name as an existing team (note that the other way around is also
disallowed).

Fixes #836

Signed-off-by: Miquel Sabaté Solà <msabate@suse.com>

app/models/user.rb

@@ -46,7 +46,7 @@ class User < ActiveRecord::Base
     }
 
   # Actions performed before/after create.
-  validate :private_namespace_available, on: :create
+  validate :private_namespace_and_team_available, on: :create
   after_create :create_personal_namespace!
 
   has_many :team_users
@@ -64,9 +64,11 @@ def email_required?
     !(Portus::LDAP.enabled? && !ldap_name.nil?)
   end
 
-  def private_namespace_available
-    return unless Namespace.exists?(name: username)
-    errors.add(:username, "cannot be used as name for private namespace")
+  # It adds an error if the username clashes with either a namespace or a team.
+  def private_namespace_and_team_available
+    return unless Namespace.exists?(name: username) || Team.exists?(name: username)
+    errors.add(:username, "'#{username}' cannot be used: there's either a "\
+      "namespace or a team named like this.")
   end
 
   # Returns true if the current user is the Portus user.
@@ -81,10 +83,13 @@ def create_personal_namespace!
     # the registry is not configured yet, we cannot create the namespace
     return unless Registry.any?
 
-    team = Team.find_by(name: username)
-    if team.nil?
-      team = Team.create!(name: username, owners: [self], hidden: true)
-    end
+    # Leave early if the namespace already exists.
+    ns = Namespace.find_by(name: username)
+    return ns if ns
+
+    # Note that this shouldn't be a problem since the User controller will make
+    # sure that we don't create a user that clashes with this team.
+    team = Team.create!(name: username, owners: [self], hidden: true)
 
     default_description = "This personal namespace belongs to #{username}."
     Namespace.find_or_create_by!(

spec/models/user_spec.rb

@@ -47,7 +47,8 @@
     expect(user.save).to be false
     expect(user.errors.size).to eq(1)
     expect(user.errors.first)
-      .to match_array([:username, "cannot be used as name for private namespace"])
+      .to match_array([:username, "'coolname' cannot be used: there's either a namespace or " \
+        "a team named like this."])
   end
 
   it "#email_required?" do