demo: Add FastAPI Example (#14)

Author: SHARANTANGEDA

demo/fastapi_langchain/__init__.py

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+uvicorn main:app --port 6000 --reload

demo/fastapi_langchain/local.sh

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+import os
+
+from fastapi import FastAPI
+from starlette.middleware.gzip import GZipMiddleware
+from starlette_exporter import PrometheusMiddleware, handle_metrics
+
+from xpuls.mlmonitor.langchain.instrument import LangchainTelemetry
+
+service_name = "xpuls AI demo service"
+app = FastAPI(
+    title=service_name,
+    description="",
+    version="0.0.1"
+)
+app.add_middleware(GZipMiddleware, minimum_size=1000)
+app.add_middleware(PrometheusMiddleware, app_name=service_name, group_paths=True)
+app.add_route("/metrics", handle_metrics)  # Metrics are published at this endpoint
+
+# Initialise xpuls.ai
+default_labels = {"service": "xpulsai-demo-service", "namespace": "mlops",
+                  "agent_name": "not_found"}
+
+os.environ["XPULSAI_TRACING_ENABLED"] = "true"  # ENABLE THIS ONLY IF ADVANCED xpuls.ai MONITORING IS REQUIRED
+
+# xpuls_host_url is an optional parameter and required if `XPULSAI_TRACING_ENABLED` is enabled
+LangchainTelemetry(default_labels=default_labels, xpuls_host_url='https://api.xpuls.ai').auto_instrument()
+
+@app.get('/healthcheck')
+def health_check():
+    return "ping!"

demo/fastapi_langchain/main.py

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+fastapi
+starlette-exporter
+starlette
+uvicorn