Add media-server auto-detection — pick Emby or Jellyfin by actual running state

common.sh

@@ -439,6 +439,9 @@ is_in_list() {
 #   EMBY_CONTAINER            ← HOST*_EMBY_CONTAINER
 #   EMBY_URL                  ← HOST*_EMBY_URL
 #   EMBY_API_KEY              ← HOST*_EMBY_API_KEY
+#   JELLYFIN_CONTAINER        ← HOST*_JELLYFIN_CONTAINER
+#   JELLYFIN_URL              ← HOST*_JELLYFIN_URL
+#   JELLYFIN_API_KEY          ← HOST*_JELLYFIN_API_KEY
 #   GITEA_API_TOKEN           ← HOST*_GITEA_API_TOKEN
 #
 # Arr-specific vars set by detect_hosts() when needed by arr scripts:
@@ -531,6 +534,13 @@ detect_hosts() {
     EMBY_API_KEY_VAR="${MY_ID}_EMBY_API_KEY"
     EMBY_API_KEY="${!EMBY_API_KEY_VAR:-}"
 
+    JELLYFIN_CONTAINER_VAR="${MY_ID}_JELLYFIN_CONTAINER"
+    JELLYFIN_CONTAINER="${!JELLYFIN_CONTAINER_VAR:-}"
+    JELLYFIN_URL_VAR="${MY_ID}_JELLYFIN_URL"
+    JELLYFIN_URL="${!JELLYFIN_URL_VAR:-}"
+    JELLYFIN_API_KEY_VAR="${MY_ID}_JELLYFIN_API_KEY"
+    JELLYFIN_API_KEY="${!JELLYFIN_API_KEY_VAR:-}"
+
     GITEA_API_TOKEN_VAR="${MY_ID}_GITEA_API_TOKEN"
     GITEA_API_TOKEN="${!GITEA_API_TOKEN_VAR:-}"
 
@@ -1363,6 +1373,77 @@ emby_api() {
     echo "$body"
 }
 
+# ── Media Server Detection ────────────────────────────────────────────────────
+# Picks whichever media server is actually running right now, so callers don't have to
+# hardcode Emby or Jellyfin. Emby is preferred when both are up (it's the primary player on
+# every host; Jellyfin is mainly kept around for its working ffprobe binary — see
+# HOST*_FFPROBE_CONTAINER). Either container being merely *configured* in host*.conf doesn't
+# count — this checks Docker's actual running state, so a host with Jellyfin installed but
+# stopped correctly falls through to Emby (or to nothing, if neither is up).
+#
+# Requires detect_hosts() to have already run (needs EMBY_*/JELLYFIN_* aliases).
+# Sets: MEDIA_SERVER ("Emby"|"Jellyfin"|""), MEDIA_SERVER_URL, MEDIA_SERVER_API_KEY.
+# Returns 1 and leaves MEDIA_SERVER="" if neither configured container is running.
+# Usage: detect_media_server [docker_timeout_seconds]
+detect_media_server() {
+    local docker_timeout="${1:-10}"
+    MEDIA_SERVER="" MEDIA_SERVER_URL="" MEDIA_SERVER_API_KEY=""
+
+    local emby_up=false jellyfin_up=false
+
+    if [[ -n "${EMBY_CONTAINER:-}" ]]; then
+        [[ "$(timeout "$docker_timeout" docker inspect -f '{{.State.Running}}' \
+            "$EMBY_CONTAINER" 2>/dev/null)" == "true" ]] && emby_up=true
+    fi
+    if [[ -n "${JELLYFIN_CONTAINER:-}" ]]; then
+        [[ "$(timeout "$docker_timeout" docker inspect -f '{{.State.Running}}' \
+            "$JELLYFIN_CONTAINER" 2>/dev/null)" == "true" ]] && jellyfin_up=true
+    fi
+
+    if [[ "$emby_up" == true && "$jellyfin_up" == true ]]; then
+        log "Both Emby and Jellyfin are running — using Emby (primary)"
+    elif [[ "$emby_up" == true ]]; then
+        log "Emby is running, Jellyfin is not — using Emby"
+    elif [[ "$jellyfin_up" == true ]]; then
+        log "Jellyfin is running, Emby is not — using Jellyfin"
+    else
+        warn "Neither Emby nor Jellyfin is running — no media server available"
+        return 1
+    fi
+
+    if [[ "$emby_up" == true ]]; then
+        MEDIA_SERVER="Emby"
+        MEDIA_SERVER_URL="$EMBY_URL"
+        MEDIA_SERVER_API_KEY="$EMBY_API_KEY"
+    else
+        MEDIA_SERVER="Jellyfin"
+        MEDIA_SERVER_URL="$JELLYFIN_URL"
+        MEDIA_SERVER_API_KEY="$JELLYFIN_API_KEY"
+    fi
+}
+
+# General REST call against whichever server detect_media_server() picked. Jellyfin accepts
+# the same X-Emby-Token header Emby uses (inherited from its Emby-fork lineage — confirmed
+# live 2026-07-19), so one call shape covers both backends.
+# Usage: detect_media_server && media_server_api <endpoint> [timeout_seconds]
+# Prints response body on 200; returns 1 on HTTP error, curl failure, or no server detected.
+media_server_api() {
+    local endpoint="$1" max_time="${2:-30}"
+    if [[ -z "${MEDIA_SERVER:-}" ]]; then
+        error "media_server_api called with no MEDIA_SERVER set — call detect_media_server first"
+        return 1
+    fi
+    local response http_code body
+    response=$(curl -sf --max-time "$max_time" \
+        -H "X-Emby-Token: $MEDIA_SERVER_API_KEY" \
+        -w "\n%{http_code}" \
+        "${MEDIA_SERVER_URL}/${endpoint}" 2>/dev/null)
+    http_code=$(echo "$response" | tail -1)
+    body=$(echo "$response" | head -n -1)
+    [[ "$http_code" != "200" ]] && { error "$MEDIA_SERVER API HTTP $http_code: $endpoint"; return 1; }
+    echo "$body"
+}
+
 # Stop containers on the REMOTE server via SSH.
 # Reads CRITICAL_CONTAINER_NAMES — set from profile arrays by rsync.sh.
 # Tracks running state in RUNNING_CONTAINERS for restart after sync.