[Unit]
Description=llama-server router — {{ llm_router_models_dir }} (OpenAI-compatible, port {{ llm_router_port }})
Documentation=https://github.com/ggml-org/llama.cpp
After=network.target nvidia-persistenced.service
Wants=nvidia-persistenced.service

[Service]
Type=simple
User={{ llm_service_user }}
Group={{ llm_service_user }}
Environment="HOME=/home/{{ llm_service_user }}"
ExecStart={{ llm_binary_path }} \
{% if llm_router_preset_enabled | default(false) %}
    --models-preset {{ llm_router_preset_path }} \
{% else %}
    --models-dir {{ llm_router_models_dir }} \
{% endif %}
    --models-max {{ llm_router_models_max }} \
    --host {{ llm_router_bind_address }} \
    --port {{ llm_router_port }} \
    --n-gpu-layers {{ llm_router_gpu_layers }} \
{% if not (llm_router_preset_enabled | default(false)) %}
    --ctx-size {{ llm_router_ctx_size }} \
    --flash-attn {{ llm_router_flash_attn }} \
{% endif %}
    --cache-type-k {{ llm_router_cache_type_k }} \
    --cache-type-v {{ llm_router_cache_type_v }} \
    --batch-size {{ llm_router_batch_size }} \
    --ubatch-size {{ llm_router_ubatch_size }} \
    --parallel {{ llm_router_parallel }} \
    --metrics

# ROUTER MODE NOTES (2026-08-12, t_0cca74a2 / updated t_9adf0889):
# - NO -m/--model flag: this is what enables llama-server router/supervisor mode.
#   Without -m, llama-server discovers all .gguf files in --models-dir, or uses
#   the per-model definitions in a --models-preset INI file.
# - PRESET MODE (t_9adf0889, 2026-08-12):
#   llm_router_preset_enabled=true switches from --models-dir to --models-preset.
#   Preset mode adds alias support (--models-dir cannot assign aliases).
#   The preset INI is at {{ llm_router_preset_path | default('/opt/llama-server-router-preset.ini') }}.
#   Both the section name and the alias field in the INI work as model IDs.
#   GH #22364 (extra "default" entry in /v1/models) is expected in preset mode — cosmetic.
# - --models-max {{ llm_router_models_max }} is driven by llm_router_models_max
#   (default 1 in defaults/main.yml; overridden to 4 in host_vars/astro-orbiter
#   as of t_33acbb2e after VRAM budget review — see host_vars for OOM risk note).
#   Default llama-server cap is 4 simultaneous — OOM on 24GB if all 3 current
#   GGUFs load at once. LRU eviction mitigates in practice but review before adding
#   models. See host_vars/astro-orbiter/vars.yml for full VRAM breakdown.
# - Clients select a model via "model": "<section-name-or-alias>" in their
#   chat completion request. Hermes sends model: "<id>" on every request already.
# - Cold model load on first request: ~30-60s for Qwen3.6-35B. First response
#   will be slow. This is expected. Document in runbook.
# - No --jinja flag: Qwen3.6-35B uses its own embedded chat template correctly.
#   If per-model template overrides are ever needed, use --models-preset INI
#   (but note GH #23460: sampler params in presets may not work in router mode).
#
# SHADOW DEPLOYMENT NOTE (historical — 2026-08-12, t_0cca74a2):
# This unit was originally deployed on port 8003 as a shadow. After validation,
# it was promoted to production on port 8002 (t_cd0d5388). The --port value
# above is the authoritative value; the port 8003 references below are historical.
# Production is now llama-server-router (this unit); llama-server-qwen is the rollback target.
Restart=on-failure
RestartSec=10
TimeoutStartSec=600
StandardOutput=journal
StandardError=journal
SyslogIdentifier=llama-server-router

[Install]
WantedBy=multi-user.target