NixOS
diff --git a/nixos/doc/manual/configuration/configuration.xml b/nixos/doc/manual/configuration/configuration.xml
@@ -21,6 +21,7 @@
  <xi:include href="xfce.xml" />
  <xi:include href="networking.xml" />
  <xi:include href="linux-kernel.xml" />
+ <xi:include href="matrix.xml" />
  <xi:include href="../generated/modules.xml" xpointer="xpointer(//section[@id='modules']/*)" />
  <xi:include href="profiles.xml" />
  <xi:include href="kubernetes.xml" />

diff --git a/nixos/doc/manual/configuration/matrix.xml b/nixos/doc/manual/configuration/matrix.xml
@@ -0,0 +1,197 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         version="5.0"
+         xml:id="module-services-matrix">
+ <title>Matrix</title>
+ <para>
+  <link xlink:href="https://matrix.org/">Matrix</link>
+  is an open standard for interoperable, decentralised, real-time communication over IP.
+  It can be used to power Instant Messaging, VoIP/WebRTC signalling, Internet of Things communication -
+  or anywhere you need a standard HTTP API for publishing and subscribing to data whilst tracking the conversation history.
+ </para>
+ <para>
+  This chapter will show you how to set up your own, self-hosted Matrix homeserver using the Synapse reference homeserver,
+  and how to serve your own copy of the Riot web client.
+  See the <link xlink:href="https://matrix.org/docs/projects/try-matrix-now.html">Try Matrix Now!</link>
+  overview page for links to Riot Apps for Android and iOS, desktop clients,
+  as well as bridges to other networks and other projects around Matrix.
+ </para>
+
+ <section xml:id="module-services-matrix-synapse">
+  <title>Synapse Homeserver</title>
+  <para>
+   <link xlink:href="https://github.com/matrix-org/synapse">Synapse</link>
+   is the reference homeserver implementation of Matrix from the core development team at matrix.org.
+   The following configuration example will set up a synapse server for the <literal>example.org</literal>
+   domain, served from the host <literal>myhostname.example.org</literal>.
+   For more information, please refer to the
+   <link xlink:href="https://github.com/matrix-org/synapse#synapse-installation">
+    installation instructions of Synapse
+   </link>.
+   <programlisting>
+    let
+      fqdn =
+        let
+          join = hostName: domain: hostName + optionalString (domain != null) ".${domain}";
+        in join config.networking.hostName config.networking.domain;
+    in {
+      networking = {
+        hostName = "myhostname";
+        domain = "example.org";
+      };
+      networking.firewall.allowedTCPPorts = [ 80 443 ];
+
+      services.nginx = {
+        enable = true;
+        # only recommendedProxySettings and recommendedGzipSettings are strictly required,
+        # but the rest make sense as well
+        recommendedTlsSettings = true;
+        recommendedOptimisation = true;
+        recommendedGzipSettings = true;
+        recommendedProxySettings = true;
+
+        virtualHosts = {
+          # This host section can be placed on a different host than the rest,
+          # i.e. to delegate from the host being accessible as ${config.networking.domain}
+          # to another host actually running the Matrix homeserver.
+          "${config.networking.domain}" = {
+            locations."= /.well-known/matrix/server".extraConfig =
+              let
+                # use 443 instead of the default 8448 port to unite
+                # the client-server and server-server port for simplicity
+                server = { "m.server" = "${fqdn}:443"; };
+              in ''
+                add_header Content-Type application/json;
+                return 200 '${builtins.toJSON server}';
+              '';
+            locations."= /.well-known/matrix/client".extraConfig =
+              let
+                client = {
+                  "m.homeserver" =  { "base_url" = "https://${fqdn}"; };
+                  "m.identity_server" =  { "base_url" = "https://vector.im"; };
+                };
+              # ACAO required to allow riot-web on any URL to request this json file
+              in ''
+                add_header Content-Type application/json;
+                add_header Access-Control-Allow-Origin *;
+                return 200 '${builtins.toJSON client}';
+              '';
+          };
+
+          # Reverse proxy for Matrix client-server and server-server communication
+          ${fqdn} = {
+            enableACME = true;
+            forceSSL = true;
+
+            # Or do a redirect instead of the 404, or whatever is appropriate for you.
+            # But do not put a Matrix Web client here! See the Riot Web section below.
+            locations."/".extraConfig = ''
+              return 404;
+            '';
+
+            # forward all Matrix API calls to the synapse Matrix homeserver
+            locations."/_matrix" = {
+              proxyPass = "http://[::1]:8008";
+            };
+          };
+        };
+      };
+      services.matrix-synapse = {
+        enable = true;
+        server_name = config.networking.domain;
+        listeners = [
+          {
+            port = 8008;
+            bind_address = "::1";
+            type = "http";
+            tls = false;
+            x_forwarded = true;
+            resources = [
+              { names = [ "client" "federation" ]; compress = false; }
+            ];
+          }
+        ];
+      };
+    };
+   </programlisting>
+  </para>
+  <para>
+   If the <code>A</code> and <code>AAAA</code> DNS records on <literal>example.org</literal>
+   do not point on the same host as the records for <code>myhostname.example.org</code>,
+   you can easily move the <code>/.well-known</code> virtualHost section of the code
+   to the host that is serving <literal>example.org</literal>,
+   while the rest stays on <literal>myhostname.example.org</literal>
+   with no other changes required.
+   This pattern also allows to seamlessly move the homeserver from <literal>myhostname.example.org</literal>
+   to <literal>myotherhost.example.org</literal> by only changing the <code>/.well-known</code> redirection target.
+  </para>
+
+  <para>
+   If you want to run a server with public registration by anybody,
+   you can then enable
+   <option>services.matrix-synapse.enable_registration = true;</option>.
+   Otherwise, or you can generate a registration secret with <command>pwgen -s 64 1</command>
+   and set it with
+   <option>services.matrix-synapse.registration_shared_secret</option>.
+   To create a new user or admin,
+   run the following after you have set the secret and have rebuilt NixOS:
+
+   <programlisting>
+    $ nix run nixpkgs.matrix-synapse
+    $ register_new_matrix_user -k &lt;your-registration-shared-secret&gt; http://localhost:8008
+    New user localpart: &lt;your-username&gt;
+    Password:
+    Confirm password:
+    Make admin [no]:
+    Success!
+   </programlisting>
+   In the example, this would create a user with the Matrix Identifier
+   <literal>@your-username:example.org</literal>.
+   Note that the registration secret ends up in the nix store and therefore is world-readable
+   by any user on your machine, so it makes sense to only temporarily activate the
+   <option>registration_shared_secret</option> option until a better solution for NixOS is in place.
+  </para>
+ </section>
+
+ <section xml:id="module-services-matrix-riot-web">
+  <title>Riot Web Client</title>
+  <para>
+   <link xlink:href="https://github.com/vector-im/riot-web/">Riot Web</link>
+   is the reference web client for Matrix and developed by the core team at matrix.org.
+   The following snippet can be optionally added to the code before to complete the synapse
+   installation with a web client served at
+   <code>https://riot.myhostname.example.org</code> and <code>https://riot.example.org</code>.
+   Alternatively, you can use the hosted copy at
+   <link xlink:href="https://riot.im/app">https://riot.im/app</link>,
+   or use other web clients or native client applications.
+   Due to the <literal>/.well-known</literal> urls set up done above,
+   many clients should fill in the required connection details automatically
+   when you enter your Matrix Identifier.
+   See <link xlink:href="https://matrix.org/docs/projects/try-matrix-now.html">Try Matrix Now!</link>
+   for a list of existing clients and their supported featureset.
+
+   <programlisting>
+     services.nginx.virtualHosts."riot.${fqdn}" = {
+       enableACME = true;
+       forceSSL = true;
+       serverAliases = [
+        "riot.${config.networking.domain}"
+       ];
+
+       root = pkgs.riot-web;
+     };
+   </programlisting>
+  </para>
+  <para>
+   Note that the Riot developers do not recommend running Riot and your Matrix homeserver
+   on the same fully-qualified domain name for security reasons.
+   In the example, this means that you should not reuse the <literal>myhostname.example.org</literal>
+   virtualHost to also serve Riot, but instead serve it on a different subdomain,
+   like <literal>riot.example.org</literal> in the example.
+   See the
+   <link xlink:href="https://github.com/vector-im/riot-web#important-security-note">Riot Important Security Notes</link>
+   for more information on this subject.
+  </para>
+ </section>
+</chapter>
diff --git a/nixos/doc/manual/release-notes/rl-1903.xml b/nixos/doc/manual/release-notes/rl-1903.xml
@@ -469,6 +469,8 @@
     and will be <link xlink:href="https://matrix.org/blog/2019/02/05/synapse-0-99-0/">the last version to accept self-signed certificates</link>.
     As such, it is now recommended to use a proper certificate verified by a
     root CA (for example Let's Encrypt).
+    The new <link linkend="module-services-matrix">manual chapter on Matrix</link> contains a working example of using nginx as a reverse proxy
+    in front of <literal>matrix-synapse</literal>, using Let's Encrypt certificates.
    </para>
   </listitem>
    <listitem>
@@ -553,6 +555,15 @@
        of maintainers.
      </para>
    </listitem>
+   <listitem>
+    <para>
+     The manual gained a
+     <link linkend="module-services-matrix">
+      new chapter on self-hosting <literal>matrix-synapse</literal> and <literal>riot-web</literal>
+     </link>, the most prevalent server and client implementations for the
+     <link xlink:href="https://matrix.org/">Matrix</link> federated communication network.
+    </para>
+   </listitem>
    <listitem>
      <para>
        The astah-community package was removed from nixpkgs due to it being discontinued and the downloads not being available anymore.

diff --git a/nixos/modules/installer/tools/nixos-install.sh b/nixos/modules/installer/tools/nixos-install.sh
@@ -138,7 +138,18 @@ fi
 # Ask the user to set a root password, but only if the passwd command
 # exists (i.e. when mutable user accounts are enabled).
 if [[ -z $noRootPasswd ]] && [ -t 0 ]; then
-    nixos-enter --root "$mountPoint" -c '[[ -e /nix/var/nix/profiles/system/sw/bin/passwd ]] && echo "setting root password..." && /nix/var/nix/profiles/system/sw/bin/passwd'
+    if nixos-enter --root "$mountPoint" -c 'test -e /nix/var/nix/profiles/system/sw/bin/passwd'; then
+        set +e
+        nixos-enter --root "$mountPoint" -c 'echo "setting root password..." && /nix/var/nix/profiles/system/sw/bin/passwd'
+        exit_code=$?
+        set -e
+
+        if [[ $exit_code != 0 ]]; then
+            echo "Setting a root password failed with the above printed error."
+            echo "You can set the root password manually by executing \`nixos-enter --root ${mountPoint@Q}\` and then running \`passwd\` in the shell of the new system."
+            exit $exit_code
+        fi
+    fi
 fi
 
 echo "installation finished!"
diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
@@ -129,7 +129,6 @@
   ./programs/sysdig.nix
   ./programs/systemtap.nix
   ./programs/sway.nix
-  ./programs/sway-beta.nix
   ./programs/thefuck.nix
   ./programs/tmux.nix
   ./programs/udevil.nix
@@ -573,6 +572,7 @@
   ./services/networking/keepalived/default.nix
   ./services/networking/keybase.nix
   ./services/networking/kippo.nix
+  ./services/networking/knot.nix
   ./services/networking/kresd.nix
   ./services/networking/lambdabot.nix
   ./services/networking/libreswan.nix

diff --git a/nixos/modules/programs/sway-beta.nix b/nixos/modules/programs/sway-beta.nix