GitSwarm-EE 2017.1-1 Documentation


LDAP

GitSwarm EE integrates with LDAP to support user authentication. This integration works with most LDAP-compliant directory servers, including Microsoft Active Directory, Apple Open Directory, Open LDAP, and 389 Server. GitSwarm EE includes enhanced integration, including group membership syncing.

Security

GitSwarm EE assumes that LDAP users are not able to change their LDAP 'mail', 'email' or 'userPrincipalName' attribute. An LDAP user who is allowed to change their email on the LDAP server can potentially take over any account on your GitSwarm EE server.

We recommend against using LDAP integration if your LDAP users are allowed to change their 'mail', 'email' or 'userPrincipalName' attribute on the LDAP server.

User deletion

If a user is deleted from the LDAP server, they will be blocked in GitSwarm EE, as well. Users will be immediately blocked from logging in. However, there is an LDAP check cache time (sync time) of one hour (see note). This means users that are already logged in or are using Git over SSH will still be able to access GitSwarm EE for up to one hour. Manually block the user in the GitSwarm EE Admin area to immediately block all access.

Note: GitSwarm EE supports a configurable sync time, with a default of one hour.

Configuration

To enable LDAP integration you need to add your LDAP server settings in /etc/gitswarm/gitswarm.rb or /home/git/gitlab/config/gitlab.yml.

Note: In GitSwarm EE, you can configure multiple LDAP servers to connect to one GitSwarm EE server.

Prior to version 2015.3, GitSwarm EE used a different syntax for configuring LDAP integration. The old LDAP integration syntax still works but may be removed in a future version. If your gitswarm.rb or gitlab.yml file contains LDAP settings in both the old syntax and the new syntax, only the old syntax will be used by GitSwarm EE.

The configuration inside gitlab_rails['ldap_servers'] below is sensitive to incorrect indentation. Be sure to retain the indentation given in the example. Copy/paste can sometimes cause problems.

Package installation configuration

gitlab_rails['ldap_enabled'] = true
gitlab_rails['ldap_servers'] = YAML.load <<-EOS # remember to close this block with 'EOS' below
main: # 'main' is the GitSwarm EE 'provider ID' of this LDAP server
  ## label
  #
  # A human-friendly name for your LDAP server. It is OK to change the label later,
  # for instance if you find out it is too large to fit on the web page.
  #
  # Example: 'Paris' or 'Acme, Ltd.'
  label: 'LDAP'

  host: '_your_ldap_server'
  port: 389
  uid: 'sAMAccountName'
  method: 'plain' # "tls" or "ssl" or "plain"
  bind_dn: '_the_full_dn_of_the_user_you_will_bind_with'
  password: '_the_password_of_the_bind_user'

  # Set a timeout, in seconds, for LDAP queries. This helps avoid blocking
  # a request if the LDAP server becomes unresponsive.
  # A value of 0 means there is no timeout.
  timeout: 10

  # This setting specifies if LDAP server is Active Directory LDAP server.
  # For non AD servers it skips the AD specific queries.
  # If your LDAP server is not AD, set this to false.
  active_directory: true

  # If allow_username_or_email_login is enabled, GitSwarm EE ignores everything
  # after the first '@' in the LDAP username submitted by the user on login.
  #
  # Example:
  # - the user enters 'jane.doe@example.com' and 'p@ssw0rd' as LDAP credentials;
  # - GitSwarm EE queries the LDAP server with 'jane.doe' and 'p@ssw0rd'.
  #
  # If you are using "uid: 'userPrincipalName'" on ActiveDirectory you need
  # to disable this setting, because the userPrincipalName contains an '@'.
  allow_username_or_email_login: false

  # To maintain tight control over the number of active users on your
  # GitSwarm EE installation, enable this setting to keep new users blocked
  # until they have been cleared by the admin (default: false).
  block_auto_created_users: false

  # Base where we can search for users
  #
  #   Ex. ou=People,dc=gitswarm,dc=example
  #
  base: ''

  # Filter LDAP users
  #
  #   Format: RFC 4515 https://tools.ietf.org/search/rfc4515
  #   Ex. (employeeType=developer)
  #
  #   Note: GitSwarm EE does not support omniauth-ldap's custom filter syntax.
  #
  user_filter: ''

  # LDAP attributes that GitSwarm EE uses to create an account for the LDAP
  # user. The specified attribute can either be the attribute name as a
  # string (e.g. 'mail'), or an array of attribute names to try in order
  # (e.g. ['mail', 'email']). Note that the user's LDAP login will always
  # be the attribute specified as `uid` above.
  attributes:
    # The username is used in paths for the user's own projects (like
    # `gitswarm.example.com/username/project`) and when mentioning them in
    # issues, merge request and comments (like `@username`). If the
    # attribute specified for `username` contains an email address, the
    # GitSwarm EE username will be the part of the email address before the
    # '@'.
    username: ['uid', 'userid', 'sAMAccountName']
    email:    ['mail', 'email', 'userPrincipalName']

    # If no full name could be found at the attribute specified for `name`,
    # the full name is determined using the attributes specified for
    # `first_name` and `last_name`.
    name:       'cn'
    first_name: 'givenName'
    last_name:  'sn'

  ## EE only

  # Base where we can search for groups
  #
  #   Ex. ou=groups,dc=gitswarm,dc=example
  #
  group_base: ''

  # The CN of a group containing GitSwarm EE administrators
  #
  #   Ex. administrators
  #
  #   Note: Not `cn=administrators` or the full DN
  #
  admin_group: ''

  # The LDAP attribute containing a user's public SSH key
  #
  #   Ex. ssh_public_key
  #
  sync_ssh_keys: false

# GitSwarm EE only: add more LDAP servers
# Choose an ID made of a-z and 0-9 . This ID will be stored in the database
# so that GitSwarm EE can remember which LDAP server a user belongs to.
# uswest2:
#   label:
#   host:
#   ....
EOS

Source installation configuration

Use the same format as gitlab_rails['ldap_servers'] for the contents under servers: in the example below:

production:
  # snip...
  ldap:
    enabled: false
    servers:
      main: # 'main' is the GitSwarm EE 'provider ID' of this LDAP server
        ## label
        #
        # A human-friendly name for your LDAP server. It is OK to change
        # the label later, for instance if you find out it is too large to
        # fit on the web page.
        #
        # Example: 'Paris' or 'Acme, Ltd.'
        label: 'LDAP'
        # snip...

Using an LDAP filter to limit access to your GitSwarm EE server

If you want to limit all GitSwarm EE access to a subset of the LDAP users on your LDAP server, the first step should be to narrow the configured base. However, it is sometimes necessary to filter users further. In this case, you can set up an LDAP user filter. The filter must comply with RFC 4515.

Package installations

gitlab_rails['ldap_servers'] = YAML.load <<-EOS
main:
  # snip...
  user_filter: '(employeeType=developer)'
EOS

Source installations

production:
  ldap:
    servers:
      main:
        # snip...
        user_filter: '(employeeType=developer)'

Tip: If you want to limit access to the nested members of an Active Directory group you can use the following syntax:

(memberOf:1.2.840.113556.1.4.1941:=CN=My Group,DC=Example,DC=com)

Please note that GitSwarm EE does not support the custom filter syntax used by omniauth-ldap.

Enabling LDAP sign-in for existing GitSwarm EE users

When a user signs in to GitSwarm EE with LDAP for the first time, and their LDAP email address is the primary email address of an existing GitSwarm EE user, then the LDAP DN will be associated with the existing user. If the LDAP email attribute is not found in GitSwarm EE's database, a new user is created.

In other words, if an existing GitSwarm EE user wants to enable LDAP sign-in for themselves, they should check that their GitSwarm EE email address matches their LDAP email address, and then sign into GitSwarm EE via their LDAP credentials.

Limitations

TLS Client Authentication

Not implemented by Net::LDAP. You should disable anonymous LDAP authentication and enable simple or SASL authentication. The TLS client authentication setting in your LDAP server cannot be mandatory and clients cannot be authenticated with the TLS protocol.

TLS Server Authentication

Not supported by GitSwarm EE's configuration options. When setting method: ssl, the underlying authentication method used by omniauth-ldap is simple_tls. This method establishes TLS encryption with the LDAP server before any LDAP-protocol data is exchanged but no validation of the LDAP server's SSL certificate is performed.

Troubleshooting

Invalid credentials when logging in

Connection Refused

If you are getting 'Connection Refused' errors when trying to connect to the LDAP server please double-check the LDAP port and method settings used by GitSwarm EE. Common combinations are method: 'plain' and port: 389, OR method: 'ssl' and port: 636.