Introduce better credential and error checking to `rake gitlab:ldap:check`

It was previously possible for invalid credential errors to go unnoticed
in this task. Users would believe everything was configured correctly and
then sign in would fail with 'invalid credentials'. This adds a specific
bind check, plus catches errors connecting to the server. Also, specs :)

2 files changed, 1 insertions, 61 deletions

diff --git a/doc/raketasks/check.md b/doc/raketasks/check.md
index 3ff3fee6a40..f7f6a40cd04 100644
--- a/doc/raketasks/check.md
+++ b/doc/raketasks/check.md
@@ -1,63 +1,3 @@
 # Check Rake Tasks
 
-## Repository Integrity
-
-Even though Git is very resilient and tries to prevent data integrity issues,
-there are times when things go wrong. The following Rake tasks intend to
-help GitLab administrators diagnose problem repositories so they can be fixed.
-
-There are 3 things that are checked to determine integrity.
-
-1. Git repository file system check ([git fsck](https://git-scm.com/docs/git-fsck)).
-   This step verifies the connectivity and validity of objects in the repository.
-1. Check for `config.lock` in the repository directory.
-1. Check for any branch/references lock files in `refs/heads`.
-
-It's important to note that the existence of `config.lock` or reference locks
-alone do not necessarily indicate a problem. Lock files are routinely created
-and removed as Git and GitLab perform operations on the repository. They serve
-to prevent data integrity issues. However, if a Git operation is interrupted these
-locks may not be cleaned up properly.
-
-The following symptoms may indicate a problem with repository integrity. If users
-experience these symptoms you may use the rake tasks described below to determine
-exactly which repositories are causing the trouble.
-
-- Receiving an error when trying to push code - `remote: error: cannot lock ref`
-- A 500 error when viewing the GitLab dashboard or when accessing a specific project.
-
-### Check all GitLab repositories
-
-This task loops through all repositories on the GitLab server and runs the
-3 integrity checks described previously.
-
-```
-# omnibus-gitlab
-sudo gitlab-rake gitlab:repo:check
-
-# installation from source
-bundle exec rake gitlab:repo:check RAILS_ENV=production
-```
-
-### Check repositories for a specific user
-
-This task checks all repositories that a specific user has access to. This is important
-because sometimes you know which user is experiencing trouble but you don't know
-which project might be the cause.
-
-If the rake task is executed without brackets at the end, you will be prompted
-to enter a username.
-
-```bash
-# omnibus-gitlab
-sudo gitlab-rake gitlab:user:check_repos
-sudo gitlab-rake gitlab:user:check_repos[<username>]
-
-# installation from source
-bundle exec rake gitlab:user:check_repos RAILS_ENV=production
-bundle exec rake gitlab:user:check_repos[<username>] RAILS_ENV=production
-```
-
-Example output:
-
-![gitlab:user:check_repos output](check_repos_output.png)
+This document was moved to [administration/raketasks/check](../administration/raketasks/check.md).
diff --git a/doc/raketasks/check_repos_output.png b/doc/raketasks/check_repos_output.png
deleted file mode 100644
index 1f632566b00..00000000000
--- a/doc/raketasks/check_repos_output.png
+++ /dev/null