Update README to reflect full data path

Without the full path, various alternative uses of ffmpeg (e.g. subtitle
extraction, image extraction) were not working. Recommend exporting the
entire Jellyfin data directory instead and make note that changing path
locations may alter this. Also includes some other tweaks to make this
work (e.g. putting the ssh public key step earlier in the NFS export).

README.md

@@ -28,15 +28,17 @@ rffmpeg supports setting multiple hosts. It keeps state in `/run/shm/rffmpeg`, o
 
 This example setup is the one I use for `rffmpeg`, involving a media server (`jf1`) and a remote transcode server (`gpu1`). Both systems run Debian GNU/Linux, though the commands below should also work on Ubuntu.
 
-1. Prepare the media server (`jf1`) with Jellyfin. Make note of the "Transcode path" in the Playback settings menu (e.g. `/var/lib/jellyfin/transcoding-temp`).
+1. Prepare the media server (`jf1`) with Jellyfin using the standard `.deb` install. Make note of main Jellyfin data path; it's usually `/var/lib/jellyfin` unless you change it. Note that if you change this path, or put the various subdirectories such as the `transcodes` or `data/subtitles` directories elsewhere, you may need to alter the NFS steps below to accommodate this. Note that Docker is not officially supported with `rffmpeg` due to the complexity of exporting Docker volumes with NFS, the path differences, and the fact that I don't use Docker, but if you do figure it out a PR is welcome.
 
-1. On the media server, create an SSH keypair owned by the Jellyfin service user; save this SSH key somewhere readable to the service user: `sudo -u jellyfin mkdir -p /var/lib/jellyfin/.ssh && sudo -u jellyfin ssh-keygen -t rsa -f /var/lib/jellyfin/.ssh/id_rsa`
+1. On the media server, create an SSH keypair owned by the Jellyfin service user; save this SSH key somewhere readable to the service user: `sudo -u jellyfin mkdir -p /var/lib/jellyfin/.ssh && sudo -u jellyfin ssh-keygen -t rsa -f /var/lib/jellyfin/.ssh/id_rsa`.
+
+1. Copy (or symlink) the new SSH public key created in the previous step to `authorized_keys`; this will be used later when the Jellyfin data directory is mounted on the transcode server: `sudo -u jellyfin cp -a /var/lib/jellyfin/.ssh/id_rsa.pub /var/lib/jellyfin/.ssh/authorized_keys`
 
 1. Install the rffmpeg program as detailed in the above section, including creating the `/etc/rffmpeg/rffmpeg.yml` configuration file and symlinks.
 
 1. Install the NFS kernel server: `sudo apt -y install nfs-kernel-server`
 
-1. Export the "Transcode path" directory found in step 1 with NFS; you will need to know the local IP address of the transcode server(s) (e.g. `10.0.0.100`) to lock this down; alternatively, use your entire local network range (e.g. `10.0.0.0/24`): `echo '/var/lib/jellyfin/transcoding-temp 10.0.0.100/32(rw,sync,no_subtree_check)' | sudo tee -a /etc/exports && sudo systemctl restart nfs-kernel-server`
+1. Export your Jellyfin data path found in step 1 with NFS; you will need to know the local IP address of the transcode server(s) (e.g. `10.0.0.100`) to lock this down; alternatively, use your entire local network range (e.g. `10.0.0.0/24`): `echo '/var/lib/jellyfin 10.0.0.100/32(rw,sync,no_subtree_check)' | sudo tee -a /etc/exports && sudo systemctl restart nfs-kernel-server`
 
 1. On the transcode server, install any required tools or programs to make use of hardware transcoding; this is optional if you only use software (i.e. CPU) transcoding.
 
@@ -46,11 +48,9 @@ This example setup is the one I use for `rffmpeg`, involving a media server (`jf
 
 1. Create a user for rffmpeg to SSH into the server as. This user should match the `jellyfin` user on the media server in every way, including UID (`id jellyfin` on the media server), home path, and groups.
 
-1. Install the SSH public key created in step 2 into the new user's home directory: `sudo -u jellyfin mkdir -p /var/lib/jellyfin/.ssh && echo 'ssh-rsa MyJellyfinUserPublicKey' | sudo -u jellyfin tee /var/lib/jellyfin/.ssh/authorized_keys`
+1. Ensure that the Jellyfin data directory exists at the same location as on the media server; create it if required, and set it immutable to prevent unintended writes: `sudo mkdir -p /var/lib/jellyfin && sudo chattr +i /var/lib/jellyfin`
 
-1. Ensure that the "Transcode path" directory exists at the same location as on the media server; create it if required: `sudo mkdir -p /var/lib/jellyfin/transcoding-temp`
-
-1. Mount the media server NFS transcode share at the transcode directory: `echo 'jf1:/var/lib/jellyfin/transcoding-temp /var/lib/jellyfin/transcoding-temp nfs defaults,vers=3,sync 0 0' | sudo tee -a /etc/fstab && sudo mount -a`
+1. Mount the media server NFS data share at the same directory on the transcode server: `echo 'jf1:/var/lib/jellyfin /var/lib/jellyfin nfs defaults,vers=3,sync 0 0' | sudo tee -a /etc/fstab && sudo mount -a`
 
 1. Mount your media directory on the transcode server at the same location as on the media server and using the same method; if your media is local to the media server, export it with NFS similarly to the transcode directory.
 
@@ -69,3 +69,5 @@ This example setup is the one I use for `rffmpeg`, involving a media server (`jf
     1. The FFmpeg process writes the output files to the NFS-mounted temporary transcoding directory.
 
     1. Jellyfin reads the output files from the NFS-exported temporary transcoding directory and plays back normally.
+
+1. `rffmpeg` will also be used during other tasks in Jellyfin that require `ffmpeg`, for instance image extraction during library scans and subtitle extraction.