docs: Add FastAPI Example to Python Examples Folder (#443)

* Update to version 0.4.0
* Add fastapi to subdirectory

examples/README.md

@@ -1,14 +1,5 @@
 # Examples
-
-We set up these examples to help you try out Pyroscope. You'll need `docker` + `docker-compose` to run them:
-
-```shell
-cd python
-docker-compose up --build
-```
-
-These are very simple projects where the application is basically one `while true` loop and inside that loop it calls a slow function and a fast function. Slow function takes about 75% of the time and the fast one takes about 25%. See [debug_python_with_pyroscope.md](https://github.com/pyroscope-io/pyroscope/blob/main/examples/debug_python_with_pyroscope.md) for a full example of how improving one function can decrease overall CPU utilization and ultimately save cut server costs by 66%!
-
+Choose a language folder to select an example for your language of choice
 
 # How Pyroscope works
 Pyroscope identifies performance issues in your application by continuously profiling the code.
@@ -24,13 +15,3 @@ There are two main components that allow Pyroscope to run smoothly and quickly:
 ## Pyroscope agent
 Every .01 seconds, the Pyroscope agent wraps around your Python, Ruby, or Go application to poll the stacktrace and calculate which function is consuming your CPU resources. 
 ![pyroscope_diagram_with_logo](../.github/markdown-images/deployment.svg)
-
-## Pyroscope Server
-Pyroscope records and aggregates what your application has been doing, then sends that data to the Pyroscope server over port `:4040`([BadgerDB](https://github.com/dgraph-io/badger)) to be processed, aggregated, and stored  for speedy queries of any time range, including:
-- [x] all of 2020
-- [x] that one day last month when that weird thing happened
-- [x] that time you deployed on a Friday and messed up everything without knowing why
-- [x] A random 10 seconds you are only querying to see if Pyroscope is legit
-
-Check out our [Demo Page](https://demo.pyroscope.io/) and select any time range to see how quickly Pyroscope works! 
-![image](https://user-images.githubusercontent.com/23323466/104861560-2ebfaa00-58e5-11eb-862e-3481f294cbcf.png)

examples/python/fastapi/Dockerfile

@@ -0,0 +1,15 @@
+FROM python:3.9
+
+# RUN pip3 install pipenv
+# COPY Pipfile ./Pipfile
+# COPY Pipfile.lock ./Pipfile.lock
+# RUN pipenv install
+
+RUN pip3 install fastapi pyroscope-io==0.4.0 uvicorn[standard]
+
+ENV FLASK_ENV=development
+ENV PYTHONUNBUFFERED=1
+
+COPY lib ./lib
+CMD [ "uvicorn", "lib.server:app", "--host", "0.0.0.0", "--port", "5000"]
+

examples/python/fastapi/README.md

@@ -0,0 +1,13 @@
+## Fastapi Example
+
+To run the example run the following commands:
+```
+# Pull latest pyroscope image:
+docker pull pyroscope/pyroscope:latest
+
+# Run the example project:
+docker-compose up --build
+
+# Reset the database (if needed):
+# docker-compose down
+```

examples/python/fastapi/lib/bike/bike.py

@@ -0,0 +1,4 @@
+from lib.utility.utility import find_nearest_vehicle
+
+def order_bike(search_radius):
+    find_nearest_vehicle(search_radius, "bike")

examples/python/fastapi/lib/car/car.py

@@ -0,0 +1,4 @@
+from lib.utility.utility import find_nearest_vehicle
+
+def order_car(search_radius):
+    find_nearest_vehicle(search_radius, "car")

examples/python/fastapi/lib/scooter/scooter.py

@@ -0,0 +1,4 @@
+from lib.utility.utility import find_nearest_vehicle
+
+def order_scooter(search_radius):
+    find_nearest_vehicle(search_radius, "scooter")

examples/python/fastapi/lib/server.py

@@ -0,0 +1,48 @@
+import os
+import time
+import pyroscope
+# from flask import Flask
+from fastapi import FastAPI
+from lib.bike.bike import order_bike
+from lib.car.car import order_car
+from lib.scooter.scooter import order_scooter
+
+pyroscope.configure(
+	app_name       = "ride-sharing-app",
+	server_address = "http://pyroscope:4040",
+	tags           = {
+        "region":   f'{os.getenv("REGION")}',
+	}
+)
+
+
+app = FastAPI()
+
+@app.get("/")
+def read_root():
+    return {"Hello": "World"}
+
+@app.get("/bike")
+def bike():
+    order_bike(0.2)
+    return "<p>Bike ordered</p>"
+
+
+@app.get("/scooter")
+def scooter():
+    order_scooter(0.3)
+    return "<p>Scooter ordered</p>"
+
+
+@app.get("/car")
+def car():
+    order_car(0.4)
+    return "<p>Car ordered</p>"
+
+
+@app.get("/")
+def environment():
+    result = "<h1>environment vars:</h1>"
+    for key, value in os.environ.items():
+        result +=f"<p>{key}={value}</p>"
+    return result

examples/python/fastapi/lib/utility/utility.py

@@ -0,0 +1,40 @@
+import time
+import pyroscope
+import os
+from datetime import datetime
+
+# How much time mutex_lock() takes relative to search_radius()
+MUTEX_LOCK_MULTIPLIER = 2
+
+# How much time check_driver_availability() takes relative to search_radius()
+DRIVER_AVAILABILITY_MULTIPLIER = 0.5
+
+def mutex_lock(n):
+    i = 0
+    start_time = time.time()
+    while time.time() - start_time < n * MUTEX_LOCK_MULTIPLIER:
+        i += 1
+
+def check_driver_availability(n):
+    i = 0
+    start_time = time.time()
+    while time.time() - start_time < n * DRIVER_AVAILABILITY_MULTIPLIER:
+        i += 1
+
+    # Every 4 minutes this will artificially create make requests in us-west-1 region slow
+    # this is just for demonstration purposes to show how performance impacts show up in the
+    # flamegraph
+
+    force_mutex_lock = datetime.today().minute * 4 % 8 == 0
+    if os.getenv("REGION") == "us-west-1" and force_mutex_lock:
+        mutex_lock(n)
+
+
+def find_nearest_vehicle(n, vehicle):
+    with pyroscope.tag_wrapper({ "vehicle": vehicle}):
+        i = 0
+        start_time = time.time()
+        while time.time() - start_time < n:
+            i += 1
+        if vehicle == "car":
+            check_driver_availability(n)

examples/python/fastapi/load-generator.py

@@ -0,0 +1,26 @@
+import random
+import requests
+import time
+
+HOSTS = [
+    'us-east-1',
+    'us-west-1',
+    'eu-west-1',
+]
+
+VEHICLES = [
+    'bike',
+    'scooter',
+    'car',
+]
+
+if __name__ == "__main__":
+    print(f"starting load generator")
+    time.sleep(3)
+    while True:
+        host = HOSTS[random.randint(0, len(HOSTS) - 1)]
+        vehicle = VEHICLES[random.randint(0, len(VEHICLES) - 1)]
+        print(f"requesting {vehicle} from {host}")
+        resp = requests.get(f'http://{host}:5000/{vehicle}')
+        print(f"received {resp}")
+        time.sleep(random.uniform(0.1, 0.2))

examples/python/Dockerfile → examples/python/flask/Dockerfile

@@ -5,7 +5,7 @@ FROM python:3.9
 # COPY Pipfile.lock ./Pipfile.lock
 # RUN pipenv install
 
-RUN pip3 install flask pyroscope-io==0.3.2
+RUN pip3 install flask pyroscope-io==0.4.0
 
 ENV FLASK_ENV=development
 ENV PYTHONUNBUFFERED=1

examples/python/flask/Dockerfile.load-generator

@@ -0,0 +1,11 @@
+FROM python:3.9
+
+RUN pip3 install requests
+
+COPY load-generator.py ./load-generator.py
+
+ENV PYTHONUNBUFFERED=1
+
+CMD [ "python", "load-generator.py" ]
+
+

examples/python/flask/README.md

@@ -0,0 +1,13 @@
+## Flask Example
+
+To run the example run the following commands:
+```
+# Pull latest pyroscope image:
+docker pull pyroscope/pyroscope:latest
+
+# Run the example project:
+docker-compose up --build
+
+# Reset the database (if needed):
+# docker-compose down
+```

examples/python/flask/docker-compose.yml

@@ -0,0 +1,33 @@
+version: '3.9'
+services:
+  us-east-1:
+    environment:
+      - REGION=us-east-1
+    build:
+      context: .
+
+  us-west-1:
+    environment:
+      - REGION=us-west-1
+    build:
+      context: .
+
+  eu-west-1:
+    environment:
+      - REGION=eu-west-1
+    build:
+      context: .
+
+  pyroscope:
+    image: pyroscope/pyroscope
+    environment:
+      - PYROSCOPE_LOG_LEVEL=debug
+    ports:
+      - '4040:4040'
+    command:
+      - 'server'
+
+  load-generator:
+    build:
+      context: .
+      dockerfile: Dockerfile.load-generator

examples/python/flask/lib/__init__.py

@@ -0,0 +1 @@
+

examples/python/flask/lib/bike/__init__.py

@@ -0,0 +1 @@
+

examples/python/flask/lib/car/__init__.py

@@ -0,0 +1 @@
+

examples/python/flask/lib/scooter/__init__.py

@@ -0,0 +1 @@
+

examples/python/flask/lib/utility/__init__.py

@@ -0,0 +1 @@
+