Я сделал простое flask приложение для практики Пулуми. Он получает переменную env через Dockerfile, и я собираюсь разместить ее на AWS Fargate и RDS Postgres в качестве базы данных. Вот приложение Flask:
import os
from flask import Flask, request
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
app = Flask(__name__)
app.config["SQLALCHEMY_DATABASE_URI"] = "postgresql://{}".format(
os.environ.get("DATABASE_URL")
)
app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
db = SQLAlchemy(app)
migrate = Migrate(app, db)
class CarsModel(db.Model):
__tablename__ = "cars"
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String())
model = db.Column(db.String())
doors = db.Column(db.Integer())
def __init__(self, name, model, doors):
self.name = name
self.model = model
self.doors = doors
def __repr__(self):
return f"<Car {self.name}>"
@app.route("/")
def hello():
return {"hello": "world"}
@app.route("/cars", methods=["POST", "GET"])
def handle_cars():
if request.method == "POST":
if request.is_json:
data = request.get_json()
new_car = CarsModel(
name=data["name"], model=data["model"], doors=data["doors"]
)
db.session.add(new_car)
db.session.commit()
return {"message": f"car {new_car.name} has been created successfully."}
else:
return {"error": "The request payload is not in JSON format"}
elif request.method == "GET":
cars = CarsModel.query.all()
results = [
{"name": car.name, "model": car.model, "doors": car.doors} for car in cars
]
return {"count": len(results), "cars": results, "message": "success"}
@app.route("/cars/<car_id>", methods=["GET", "PUT", "DELETE"])
def handle_car(car_id):
car = CarsModel.query.get_or_404(car_id)
if request.method == "GET":
response = {"name": car.name, "model": car.model, "doors": car.doors}
return {"message": "success", "car": response}
elif request.method == "PUT":
data = request.get_json()
car.name = data["name"]
car.model = data["model"]
car.doors = data["doors"]
db.session.add(car)
db.session.commit()
return {"message": f"car {car.name} successfully updated"}
elif request.method == "DELETE":
db.session.delete(car)
db.session.commit()
return {"message": f"Car {car.name} successfully deleted."}
if __name__ == "__main__":
app.run(host="0.0.0.0", port=8000)
Вот файл Docker:
# Use an official Python runtime as a parent image
FROM python:3.8
# Set the working directory to /app
WORKDIR /app
# Copy the current directory contents into the container at /app
COPY . /app
# Install any needed packages specified in requirements.txt
RUN pip install --trusted-host pypi.python.org -r requirements.txt
ENV FLASK_APP main.py
ENV DATABASE_URL localhost
RUN flask db init
RUN flask db migrate
RUN flask db upgrade
# Make port 80 available to the world outside this container
EXPOSE 8000
# Run app.py when the container launches
CMD ["python", "main.py"]
Вот файл index.ts для Pulumi:
import * as awsx from "@pulumi/awsx";
import * as aws from "@pulumi/aws";
import * as pulumi from "@pulumi/pulumi";
const vpc = new awsx.ec2.Vpc("custom");
// Step 1: Create an ECS Fargate cluster.
const cluster = new awsx.ecs.Cluster("first_cluster", { vpc });
const securityGroupIds = cluster.securityGroups.map(g => g.id);
const dbSubnets = new aws.rds.SubnetGroup("dbsubnets", {
subnetIds: vpc.publicSubnetIds,
});
const db = new aws.rds.Instance("postgresdb", {
engine: "postgres",
instanceClass: "db.t2.micro",
allocatedStorage: 20,
dbSubnetGroupName: dbSubnets.id,
vpcSecurityGroupIds: securityGroupIds,
name: "dummy",
username: "dummy",
password: "123456789",
publiclyAccessible: true,
skipFinalSnapshot: true,
});
const hosts = pulumi.all([db.endpoint.apply(e => e)]);
const environment = hosts.apply(([postgresHost]) => [
{ name: "DATABASE_URL", value: postgresHost },
]);
// Step 2: Define the Networking for our service.
const alb = new awsx.elasticloadbalancingv2.ApplicationLoadBalancer(
"net-lb", { external: true, securityGroups: cluster.securityGroups, vpc });
const atg = alb.createTargetGroup(
"app-tg", { port: 8000, deregistrationDelay: 0 });
const web = atg.createListener("web", { port: 80, external: true });
// Step 3: Build and publish a Docker image to a private ECR registry.
const img = awsx.ecs.Image.fromPath("app-img", "./app");
// Step 4: Create a Fargate service task that can scale out.
const appService = new awsx.ecs.FargateService("app-svc", {
cluster,
taskDefinitionArgs: {
container: {
image: img,
cpu: 102 /*10% of 1024*/,
memory: 50 /*MB*/,
portMappings: [web],
environment: environment,
},
},
desiredCount: 5,
}, { dependsOn: [db] });
// Step 5: Export the Internet address for the service.
export const url = web.endpoint.hostname;
Теперь, когда я делаю pulumi up, я получаю это:
sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Cannot assign requested address
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5432?
(Background on this error at: http://sqlalche.me/e/e3q8)
at /Users/myuser/projects/practice/pulumi/simple_flask_app/node_modules/@pulumi/docker.ts:546:15
at Generator.next (<anonymous>)
at fulfilled (/Users/myuser/projects/practice/pulumi/simple_flask_app/node_modules/@pulumi/docker/docker.js:18:58)
at processTicksAndRejections (internal/process/task_queues.js:97:5)
error: The command '/bin/sh -c flask db migrate' returned a non-zero code: 1
Теперь я знаю, что это потому, что он пытается подключиться к localhost, как это по умолчанию, но как передать имя хоста ресурс дб?
Спасибо
ОБНОВЛЕНИЕ 1: Попытка удаления ENV DATABASE_URL localhost
После удаления ENV DATABASE_URL localhost:
File "/usr/local/lib/python3.8/site-packages/sqlalchemy/pool/base.py", line 652, in __connect
connection = pool._invoke_creator(self)
File "/usr/local/lib/python3.8/site-packages/sqlalchemy/engine/strategies.py", line 114, in connect
return dialect.connect(*cargs, **cparams)
File "/usr/local/lib/python3.8/site-packages/sqlalchemy/engine/default.py", line 490, in connect
return self.dbapi.connect(*cargs, **cparams)
File "/usr/local/lib/python3.8/site-packages/psycopg2/__init__.py", line 127, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not translate host name "None" to address: Name or service not known
(Background on this error at: http://sqlalche.me/e/e3q8)
at /Users/myuser/projects/practice/pulumi/simple_flask_app/node_modules/@pulumi/docker.ts:546:15
at Generator.next (<anonymous>)
at fulfilled (/Users/myuser/projects/practice/pulumi/simple_flask_app/node_modules/@pulumi/docker/docker.js:18:58)