Add podman quadlet installation method (#602)

Signed-off-by: Lukas Zapletal <lzap+git@redhat.com>

docs/community-installation-guide.md

@@ -99,3 +99,113 @@ loginctl enable-linger
 podman auto-update
 podman image prune -f
 ```
+
+## Podman via systemd
+
+This method is suitable for systems which come with Podman version 5.x or higher and systemd (e.g. Fedora, CentOS Stream 9 or clones). Instructions are written for root-less mode, do not run the commands as root since paths are different. Ensure that SELinux is in enforcing mode for maximum security.
+
+Create a new volume for database:
+
+    podman volume create invidious-db
+
+Start a temporary container:
+
+    podman run --rm -it --name invidious-init -v invidious-db:/var/lib/postgresql/data:Z -p 5432:5432 -e POSTGRES_DB=invidious -e POSTGRES_USER=kemal -e POSTGRES_PASSWORD=kemal docker.io/library/postgres:14
+
+In another terminal, migrate the database:
+
+    export PGPASSWORD=kemal
+    for F in channels videos channel_videos users session_ids nonces annotations playlists playlist_videos; do
+        curl -s https://raw.githubusercontent.com/iv-org/invidious/refs/heads/master/config/sql/$F.sql | \
+            psql -h localhost -p 5432 -U kemal invidious
+    done
+
+Shutdown the temporary container, it is no longer needed. Create a database volume unit:
+
+    cat > ~/.config/containers/systemd/invidious-db.volume <<EOF
+    [Volume]
+    VolumeName=invidious-db
+    EOF
+
+And a database container:
+
+    cat > ~/.config/containers/systemd/invidious-db.container <<EOF
+    [Container]
+    ContainerName=invidious-db
+    Environment=POSTGRES_DB=invidious POSTGRES_USER=kemal POSTGRES_PASSWORD=kemal
+    Image=docker.io/library/postgres:14
+    HealthCmd=pg_isready -h localhost -p 5432 -U kemal -d invidious
+    Notify=healthy
+    Pod=invidious.pod
+    Volume=invidious-db.volume:/var/lib/postgresql/data:Z
+    EOF
+
+Create a helper container:
+
+    cat > ~/.config/containers/systemd/invidious-sig-helper.container <<EOF
+    [Container]
+    ContainerName=invidious-sig-helper
+    Environment=RUST_LOG=info
+    Image=quay.io/invidious/inv-sig-helper:latest
+    Exec=--tcp 0.0.0.0:12999
+    Pod=invidious.pod
+    EOF
+
+Generate your `VISITOR_DATA` an `PO_TOKEN` secrets. For more information about these, read the information dialog above.
+
+    podman run quay.io/invidious/youtube-trusted-session-generator
+
+Set those secrets as temporary environmental variables, also generate a random string for HMAC secret:
+
+    HMAC=$(openssl rand -base64 21)
+    VISITOR_DATA="ABCDEF%3D%3D" # notsecret
+    PO_TOKEN="MpOIfiljfsdljds-Lljfsdk-ojrdjXVs==" # notsecret
+
+In the same terminal where you defined the environmental variables, create new environmental config file:
+
+    cat > ~/.config/containers/systemd/invidious.env <<EOF
+    INVIDIOUS_DATABASE_URL="postgres://kemal:kemal@invidious-db:5432/invidious"
+    #INVIDIOUS_CHECK_TABLES=true
+    #INVIDIOUS_DOMAIN="inv.example.com"
+    INVIDIOUS_SIGNATURE_SERVER="invidious-sig-helper:12999"
+    INVIDIOUS_VISITOR_DATA="$VISITOR_DATA"
+    INVIDIOUS_PO_TOKEN="$PO_TOKEN"
+    INVIDIOUS_HMAC_KEY="$HMAC"
+    EOF
+
+From now on, if you need to change configuration just edit the generated file `~/.config/containers/systemd/invidious.env`. Now, create invidious container unit:
+
+    cat > ~/.config/containers/systemd/invidious.container <<EOF
+    [Container]
+    ContainerName=invidious
+    EnvironmentFile=%h/.config/containers/systemd/invidious.env
+    Image=quay.io/invidious/invidious:latest
+    Pod=invidious.pod
+    [Unit]
+    After=invidious-db.service
+    EOF
+
+And finally, create pod unit. Note only port 3000 is exposed, do not expose other ports!
+
+    cat > ~/.config/containers/systemd/invidious.pod <<EOF
+    [Pod]
+    PodName=invidious
+    PublishPort=3000:3000
+    [Install]
+    WantedBy=multi-user.target default.target
+    EOF
+
+Systemd units are generated on-the-fly during `daemon-reload` command, but before that let's check syntax with quadlet generator. Note, you need Podman version 5.0 or higher, older versions will not work:
+
+    /usr/libexec/podman/quadlet -dryrun -user
+
+Reload systemd daemon. Keep in mind you need to do this command every time you change a unit file, you can change the environmental file freely tho.
+
+    systemctl --user daemon-reload
+
+And the whole application can be now started:
+
+    systemctl --user start invidious-pod
+
+Keep in mind that generated units cannot be enabled using `systemctl enable`, the main pod will be enabled automatically. If you do not like this behavior, remove the `WantedBy` line from `invidious.pod`.
+