NetworkManager: Detection of Captive Portals on Debian Jessie/Stretch (self-hosted)

NetworkManager provides connectivity checking to test for captive portals since GNOME 3.14. This performs recurring checks on a configurable URL. In case this does not deliver the expected response, NetworkManager knows we are very probably behind a captive portal and opens the corresponding login page.

This connectivity checking is an optional feature and not enabled by default in Debian Jessie or Squeeze. To enable this we can simple add a configuration file in /etc/NetworkManager/conf.d containing three settings:

response=NetworkManager is online

This will check every 300 seconds and expects to find the string “NetworkManager is online” in the HTML response.

For privacy reasons you might not want to test a public URL though. We could however simply host the URL to be checked ourselves. The NetworkManager documentation gives a few more details about the three settings. We mainly need to set the URI to a web site that either returns the header “X-NetworkManager-Status” with a value of “online” or returns the string specified using “response” in its body.

Given a running Apache web server with mod_headers enabled we can simply define a vhost like this:

<VirtualHost *:80>

  ## Vhost docroot
  DocumentRoot "/var/www/empty"

  ## Directories, there should at least be a declaration for /var/www/empty

  <Directory "/var/www/empty">
    Header Set X-NetworkManager-Status "online"
    AllowOverride None
    Require all granted

  ## Logging
  ErrorLog "/var/log/apache2/connectivity-check.example.net_error.log"
  ServerSignature Off
  CustomLog "/var/log/apache2/connectivity-check.example.net_access.log" combined

and configure NetworkManager using the following in /etc/NetworkManager/conf.d/10-connectivity.conf:



  • Enabling captive portal detection in GNOME 3.14 on Debian Jessie by L Guruprasad
  • NetworkManager.conf documentation
  • etckeeper – keeping /etc in a git repository

    When having a look at git yesterday, I stumbled upon etckeeper, a tool to keep /etc in a git (or mercurial) repository and also keeps the metadata (file permissions, …) in the repo making use of metastore.

    It hooks into apt but I used /etc/portage/basrc to call it before and after installing a package:

    case “$EBUILD_PHASE” in
    elog “Running etckeeper pre-install…”
    /usr/bin/etckeeper pre-install
    elog “Running etckeeper post-install…”
    /usr/bin/etckeeper post-install

    One could also modify /etc/etckeeper/post-install.d/50vcs-commit to include the package name etc. in the commit message while emerging:

    — a/post-install.d/50vcs-commit
    +++ b/post-install.d/50vcs-commit
    @@ -2,5 +2,12 @@
    set -e

    if etckeeper unclean; then
    – etckeeper commit “committing changes after $HIGHLEVEL_PACKAGE_MANAGER run”
    + portage)
    + etckeeper commit “committing changes after $HIGHLEVEL_PACKAGE_MANAGER run ($CATEGORY/$P)”
    + ;;
    + *)
    + etckeeper commit “committing changes after $HIGHLEVEL_PACKAGE_MANAGER run”
    + ;;
    + esac

    There are probably other/better ways to accomplish this and more…

    Anyways… etckeeper looks like a nice and very flexible tool to keep /etc in a repository if one wants to.

    Matroska Dateien editieren/erstellen

    Auf der Suche nach einer Möglichkeit einen Audio Stream aus einer Matroska Containerdatei zu entfernen bin ich gerade auf MKVToolnix gestossen. Neben den üblichen Kommandozeilentools gibt’s dazu auch eine recht übersichtliche GUI, mit der das Problem im Nu gelöst war. Auch das Erstellen und ich hoffe auch Splitten von Containern sollte recht einfach gehen.

    Achja, für Gentoo gibt’s die Tools im Portage Tree als media-video/mkvtoolnix, wxwidgets USE-Flag hierbei nicht vergessen.

    linux-vserver -> openvz

    So, das Blog ist wieder da nachdem ich heute Nachmittag von VServer auf OpenVZ umgestiegen bin. Gebracht hat mir das ganze zunächst einmal ein loopback device für jeden virtuellen Server und die Möglichkeit iptables innerhalb eines virtuellen Server zu benutzen. Mal gucken wie mir das ganze in nächster Zeit gefällt.