Merge pull request #56565 from andrew-d/adunham/plex-fhs

plex: rewrite to use FHS userenv

nixos/modules/services/misc/plex.nix

@@ -10,35 +10,38 @@ in
     services.plex = {
       enable = mkEnableOption "Plex Media Server";
 
-      # FIXME: In order for this config option to work, symlinks in the Plex
-      # package in the Nix store have to be changed to point to this directory.
       dataDir = mkOption {
         type = types.str;
         default = "/var/lib/plex";
-        description = "The directory where Plex stores its data files.";
+        description = ''
+          The directory where Plex stores its data files.
+        '';
       };
 
       openFirewall = mkOption {
         type = types.bool;
         default = false;
         description = ''
-          Open ports in the firewall for the media server
+          Open ports in the firewall for the media server.
         '';
       };
 
       user = mkOption {
         type = types.str;
         default = "plex";
-        description = "User account under which Plex runs.";
+        description = ''
+          User account under which Plex runs.
+        '';
       };
 
       group = mkOption {
         type = types.str;
         default = "plex";
-        description = "Group under which Plex runs.";
+        description = ''
+          Group under which Plex runs.
+        '';
       };
 
-
       managePlugins = mkOption {
         type = types.bool;
         default = true;
@@ -80,73 +83,48 @@ in
       description = "Plex Media Server";
       after = [ "network.target" ];
       wantedBy = [ "multi-user.target" ];
-      preStart = ''
-        test -d "${cfg.dataDir}/Plex Media Server" || {
-          echo "Creating initial Plex data directory in \"${cfg.dataDir}\"."
-          mkdir -p "${cfg.dataDir}/Plex Media Server"
-          chown -R ${cfg.user}:${cfg.group} "${cfg.dataDir}"
-        }
 
-        # Copy the database skeleton files to /var/lib/plex/.skeleton
-        # See the the Nix expression for Plex's package for more information on
-        # why this is done.
-        install --owner ${cfg.user} --group ${cfg.group} -d "${cfg.dataDir}/.skeleton"
-        for db in "com.plexapp.plugins.library.db"; do
-            if [ ! -e  "${cfg.dataDir}/.skeleton/$db" ]; then
-              cp "${cfg.package}/usr/lib/plexmediaserver/Resources/base_$db" "${cfg.dataDir}/.skeleton/$db"
-            fi
-            chmod u+w "${cfg.dataDir}/.skeleton/$db"
-            chown ${cfg.user}:${cfg.group} "${cfg.dataDir}/.skeleton/$db"
-        done
-
-        # If managePlugins is enabled, setup symlinks for plugins.
-        ${optionalString cfg.managePlugins ''
-          echo "Preparing plugin directory."
-          PLUGINDIR="${cfg.dataDir}/Plex Media Server/Plug-ins"
-          test -d "$PLUGINDIR" || {
-            mkdir -p "$PLUGINDIR";
-            chown ${cfg.user}:${cfg.group} "$PLUGINDIR";
-          }
-
-          echo "Removing old symlinks."
-          # First, remove all of the symlinks in the directory.
-          for f in `ls "$PLUGINDIR/"`; do
-            if [[ -L "$PLUGINDIR/$f" ]]; then
-              echo "Removing plugin symlink $PLUGINDIR/$f."
-              rm "$PLUGINDIR/$f"
-            fi
-          done
-
-          echo "Symlinking plugins."
-          for path in ${toString cfg.extraPlugins}; do
-            dest="$PLUGINDIR/$(basename $path)"
-            if [[ ! -d "$path" ]]; then
-              echo "Error symlinking plugin from $path: no such directory."
-            elif [[ -d "$dest" || -L "$dest" ]]; then
-              echo "Error symlinking plugin from $path to $dest: file or directory already exists."
-            else
-              echo "Symlinking plugin at $path..."
-              ln -s "$path" "$dest"
-            fi
-          done
-        ''}
-     '';
       serviceConfig = {
         Type = "simple";
         User = cfg.user;
         Group = cfg.group;
-        PermissionsStartOnly = "true";
+
-        ExecStart = "\"${cfg.package}/usr/lib/plexmediaserver/Plex Media Server\"";
+        # Run the pre-start script with full permissions (the "!" prefix) so it
+        # can create the data directory if necessary.
+        ExecStartPre = let
+          preStartScript = pkgs.writeScript "plex-run-prestart" ''
+            #!${pkgs.bash}/bin/bash
+
+            # Create data directory if it doesn't exist
+            if ! test -d "$PLEX_DATADIR"; then
+              echo "Creating initial Plex data directory in: $PLEX_DATADIR"
+              install -d -m 0755 -o "${cfg.user}" -g "${cfg.group}" "$PLEX_DATADIR"
+            fi
+         '';
+        in
+          "!${preStartScript}";
+
+        ExecStart = "${cfg.package}/bin/plexmediaserver";
         KillSignal = "SIGQUIT";
         Restart = "on-failure";
       };
+
       environment = {
-        PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR=cfg.dataDir;
+        # Configuration for our FHS userenv script
-        PLEX_MEDIA_SERVER_HOME="${cfg.package}/usr/lib/plexmediaserver";
+        PLEX_DATADIR=cfg.dataDir;
+        PLEX_PLUGINS=concatMapStringsSep ":" builtins.toString cfg.extraPlugins;
+
+        # The following variables should be set by the FHS userenv script:
+        #   PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR
+        #   PLEX_MEDIA_SERVER_HOME
+
+        # Allow access to GPU acceleration; the Plex LD_LIBRARY_PATH is added
+        # by the FHS userenv script.
+        LD_LIBRARY_PATH="/run/opengl-driver/lib";
+
         PLEX_MEDIA_SERVER_MAX_PLUGIN_PROCS="6";
         PLEX_MEDIA_SERVER_TMPDIR="/tmp";
         PLEX_MEDIA_SERVER_USE_SYSLOG="true";
-        LD_LIBRARY_PATH="/run/opengl-driver/lib:${cfg.package}/usr/lib/plexmediaserver/lib";
         LC_ALL="en_US.UTF-8";
         LANG="en_US.UTF-8";
       };

pkgs/servers/plex/default.nix

@@ -1,81 +1,102 @@
-{ config, stdenv, fetchurl, rpmextract, glibc
+# The actual Plex package that we run is a FHS userenv of the "raw" package.
-, dataDir ? "/var/lib/plex" # Plex's data directory must be baked into the package due to symlinks.
+{ stdenv
-, enablePlexPass ? config.plex.enablePlexPass or false
+, buildFHSUserEnv
+, writeScript
+, plexRaw
+
+# Old argument for overriding the Plex data directory; isn't necessary for this
+# version of Plex to function, but still around for backwards-compatibility.
+, dataDir ? "/var/lib/plex"
 }:
 
-let
+buildFHSUserEnv rec {
-  plexPass = throw "Plex pass has been removed at upstream's request; please unset nixpkgs.config.plex.pass";
+  name = "plexmediaserver";
-  plexpkg = if enablePlexPass then plexPass else {
+  inherit (plexRaw) meta;
-    version = "1.15.3.876";
-    vsnHash = "ad6e39743";
-    sha256 = "01g7wccm01kg3nhf3qrmwcn20nkpv0bqz6zqv2gq5v03ps58h6g5";
-  };
 
-in stdenv.mkDerivation rec {
+  # This script is run when we start our Plex binary
-  name = "plex-${version}";
+  runScript = writeScript "plex-run-script" ''
-  version = plexpkg.version;
+    #!${stdenv.shell}
-  vsnHash = plexpkg.vsnHash;
-  sha256 = plexpkg.sha256;
 
-  src = fetchurl {
+    set -eu
-    url = "https://downloads.plex.tv/plex-media-server-new/${version}-${vsnHash}/redhat/plexmediaserver-${version}-${vsnHash}.x86_64.rpm";
-    inherit sha256;
-  };
 
-  buildInputs = [ rpmextract glibc ];
+    # The root path to our Plex installation
+    root=${plexRaw}/lib/plexmediaserver
 
-  phases = [ "unpackPhase" "installPhase" "fixupPhase" "distPhase" ];
+    # Path to where we're storing our Plex data files. We default to storing
+    # them in the user's home directory under the XDG-compatible location, but
+    # allow overriding with an environment variable so the location can be
+    # configured in our NixOS module.
+    #
+    # NOTE: the old version of Plex used /var/lib/plex as the default location,
+    # but this package shouldn't assume that we're going to run Plex with the
+    # ability to write to /var/lib, so using a subdirectory of $HOME when none
+    # is specified feels less likely to have permission errors.
+    if [[ -z "''${PLEX_DATADIR:-}" ]]; then
+      PLEX_DATADIR="$HOME/.local/share/plex"
+    fi
+    if [[ ! -d "$PLEX_DATADIR" ]]; then
+      echo "Creating Plex data directory: $PLEX_DATADIR"
+      mkdir -p "$PLEX_DATADIR"
+    fi
 
-  unpackPhase = ''
+    # The database is stored under the given directory
-    rpmextract $src
+    db="$PLEX_DATADIR/.skeleton/com.plexapp.plugins.library.db"
-  '';
 
-  installPhase = ''
+    # If we don't have a database in the expected path, then create one by
-    install -d $out/usr/lib
+    # copying our base database to that location.
-    cp -dr --no-preserve='ownership' usr/lib/plexmediaserver $out/usr/lib/
+    if ! test -f "$db"; then
+      echo "Copying base database file to: $db"
+      mkdir -p "$(dirname "$db")"
+      cat "${plexRaw.basedb}" > "$db"
+    fi
 
-    # Now we need to patch up the executables and libraries to work on Nix.
+    # Set up symbolic link at '/db', which is linked to by our Plex package
-    # Side note: PLEASE don't put spaces in your binary names. This is stupid.
+    # (see the 'plexRaw' package).
-    for bin in "Plex Media Server"              \
+    ln -s "$db" /db
-               "Plex Commercial Skipper"        \
+
-               "Plex DLNA Server"               \
+    # If we have a plugin list (set by our NixOS module), we create plugins in
-               "Plex Media Scanner"             \
+    # the data directory as expected. This is a colon-separated list of paths.
-               "Plex Relay"                     \
+    if [[ -n "''${PLEX_PLUGINS:-}" ]]; then
-               "Plex Script Host"               \
+      echo "Preparing plugin directory"
-               "Plex Transcoder"                \
+
-               "Plex Tuner Service"             ; do
+      pluginDir="$PLEX_DATADIR/Plex Media Server/Plug-ins"
-      patchelf --set-interpreter "${glibc.out}/lib/ld-linux-x86-64.so.2" "$out/usr/lib/plexmediaserver/$bin"
+      test -d "$pluginDir" || mkdir -p "$pluginDir"
-      patchelf --set-rpath "$out/usr/lib/plexmediaserver/lib" "$out/usr/lib/plexmediaserver/$bin"
+
+      # First, remove all of the symlinks in the plugins directory.
+      echo "Removing old symlinks"
+      for f in $(ls "$pluginDir/"); do
+        if [[ -L "$pluginDir/$f" ]]; then
+          echo "Removing plugin symlink: $pluginDir/$f"
+          rm "$pluginDir/$f"
+        fi
       done
 
-    find $out/usr/lib/plexmediaserver/Resources -type f -a -perm -0100 \
+      echo "Symlinking plugins"
-        -print -exec patchelf --set-interpreter "${glibc.out}/lib/ld-linux-x86-64.so.2" '{}' \;
+      IFS=':' read -ra pluginsArray <<< "$PLEX_PLUGINS"
+      for path in "''${pluginsArray[@]}"; do
+        dest="$pluginDir/$(basename "$path")"
 
-    # Our next problem is the "Resources" directory in /usr/lib/plexmediaserver.
+        if [[ ! -d "$path" ]]; then
-    # This is ostensibly a skeleton directory, which contains files that Plex
+          echo "Error symlinking plugin from $path: no such directory"
-    # copies into its folder in /var. Unfortunately, there are some SQLite
+        elif [[ -d "$dest" || -L "$dest" ]]; then
-    # databases in the directory that are opened at startup. Since these
+          echo "Error symlinking plugin from $path to $dest: file or directory already exists"
-    # database files are read-only, SQLite chokes and Plex fails to start. To
+        else
-    # solve this, we keep the resources directory in the Nix store, but we
+          echo "Symlinking plugin at: $path"
-    # rename the database files and replace the originals with symlinks to
+          ln -s "$path" "$dest"
-    # /var/lib/plex. Then, in the systemd unit, the base database files are
+        fi
-    # copied to /var/lib/plex before starting Plex.
-    RSC=$out/usr/lib/plexmediaserver/Resources
-    for db in "com.plexapp.plugins.library.db"; do
-        mv $RSC/$db $RSC/base_$db
-        ln -s "${dataDir}/.skeleton/$db" $RSC/$db
       done
-  '';
+    fi
 
-  meta = with stdenv.lib; {
+    # Tell Plex to use the data directory as the "Application Support"
-    homepage = https://plex.tv/;
+    # directory, otherwise it tries to write things into the user's home
-    license = licenses.unfree;
+    # directory.
-    platforms = platforms.linux;
+    export PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR="$PLEX_DATADIR"
-    maintainers = with stdenv.lib.maintainers; [ colemickens forkk thoughtpolice pjones lnl7 ];
+
-    description = "Media / DLNA server";
+    # Tell Plex where the 'home' directory for itself is.
-    longDescription = ''
+    export PLEX_MEDIA_SERVER_HOME="${plexRaw}/lib/plexmediaserver"
-      Plex is a media server which allows you to store your media and play it
+
-      back across many different devices.
+    # Actually run Plex, prepending LD_LIBRARY_PATH with the libraries from
+    # the Plex package.
+    LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$root exec "$root/Plex Media Server"
   '';
-  };
 }

pkgs/servers/plex/raw.nix

@@ -0,0 +1,70 @@
+{ stdenv
+, fetchurl
+, rpmextract
+}:
+
+# The raw package that fetches and extracts the Plex RPM. Override the source
+# and version of this derivation if you want to use a Plex Pass version of the
+# server, and the FHS userenv and corresponding NixOS module should
+# automatically pick up the changes.
+stdenv.mkDerivation rec {
+  version = "1.15.3.876-ad6e39743";
+  pname = "plexmediaserver";
+  name = "${pname}-${version}";
+
+  # Fetch the source
+  src = fetchurl {
+    url = "https://downloads.plex.tv/plex-media-server-new/${version}/redhat/plexmediaserver-${version}.x86_64.rpm";
+    sha256 = "01g7wccm01kg3nhf3qrmwcn20nkpv0bqz6zqv2gq5v03ps58h6g5";
+  };
+
+  outputs = [ "out" "basedb" ];
+
+  nativeBuildInputs = [ rpmextract ];
+
+  phases = [ "unpackPhase" "installPhase" "fixupPhase" "distPhase" ];
+
+  unpackPhase = ''
+    rpmextract $src
+  '';
+
+  installPhase = ''
+    mkdir -p "$out/lib"
+    cp -dr --no-preserve='ownership' usr/lib/plexmediaserver $out/lib/
+
+    # Location of the initial Plex plugins database
+    f=$out/lib/plexmediaserver/Resources/com.plexapp.plugins.library.db
+
+    # Store the base database in the 'basedb' output
+    cat $f > $basedb
+
+    # Overwrite the base database in the Plex package with an absolute symlink
+    # to the '/db' file; we create this path in the FHS userenv (see the "plex"
+    # package).
+    ln -fs /db $f
+  '';
+
+  # We're running in a FHS userenv; don't patch anything
+  dontPatchShebangs = true;
+  dontStrip = true;
+  dontPatchELF = true;
+  dontAutoPatchelf = true;
+
+  meta = with stdenv.lib; {
+    homepage = https://plex.tv/;
+    license = licenses.unfree;
+    platforms = platforms.linux;
+    maintainers = with maintainers; [
+      colemickens
+      forkk
+      lnl7
+      pjones
+      thoughtpolice
+    ];
+    description = "Media library streaming server";
+    longDescription = ''
+      Plex is a media server which allows you to store your media and play it
+      back across many different devices.
+    '';
+  };
+}

pkgs/top-level/all-packages.nix

@@ -5105,6 +5105,7 @@ in
   playbar2 = libsForQt5.callPackage ../applications/audio/playbar2 { };
 
   plex = callPackage ../servers/plex { };
+  plexRaw = callPackage ../servers/plex/raw.nix { };
 
   tautulli = callPackage ../servers/tautulli { python = python2; };