Implement API to add new short urls

.envrc.dist

@@ -1,3 +1,8 @@
 export FLASK_APP=shortener.main
 export FLASK_ENV=development
-export BASE_DOMAIN=g4b.ovh.
+export BASE_DOMAIN=g4b.ovh
+export PROVIDER=ovh
+export OVH_ENDPOINT=ovh-eu
+export OVH_APPLICATION_KEY=
+export OVH_APPLICATION_SECRET=
+export OVH_CONSUMER_KEY=

poetry.lock

@@ -161,6 +161,18 @@ category = "dev"
 optional = false
 python-versions = "*"
 
+[[package]]
+name = "ovh"
+version = "0.5.0"
+description = "\"Official OVH.com API wrapper\""
+category = "main"
+optional = false
+python-versions = "*"
+
+[package.extras]
+dev = ["coverage (==3.7.1)", "mock (==1.0.1)", "nose (==1.3.3)", "yanc (==0.2.4)", "Sphinx (==1.2.2)", "coveralls (==0.4.4)", "setuptools (>=30.3.0)", "wheel"]
+test = ["coverage (==3.7.1)", "mock (==1.0.1)", "nose (==1.3.3)", "yanc (==0.2.4)"]
+
 [[package]]
 name = "packaging"
 version = "20.9"
@@ -245,6 +257,17 @@ category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*"
 
+[[package]]
+name = "redis"
+version = "3.5.3"
+description = "Python client for Redis key-value store"
+category = "main"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
+
+[package.extras]
+hiredis = ["hiredis (>=0.1.3)"]
+
 [[package]]
 name = "six"
 version = "1.16.0"
@@ -301,7 +324,7 @@ watchdog = ["watchdog"]
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.9"
-content-hash = "dfd3993450db4fbb1625a378f1c1018769d937dfc7175ef464474ac9388deef9"
+content-hash = "7bb0d58e52c792760a354cbff8e7ae8b642d5d29fabf3210a1b32d1f5e025a81"
 
 [metadata.files]
 appdirs = [
@@ -400,6 +423,10 @@ nodeenv = [
     {file = "nodeenv-1.6.0-py2.py3-none-any.whl", hash = "sha256:621e6b7076565ddcacd2db0294c0381e01fd28945ab36bcf00f41c5daf63bef7"},
     {file = "nodeenv-1.6.0.tar.gz", hash = "sha256:3ef13ff90291ba2a4a7a4ff9a979b63ffdd00a464dbe04acf0ea6471517a4c2b"},
 ]
+ovh = [
+    {file = "ovh-0.5.0-py2.py3-none-any.whl", hash = "sha256:03c7a5e7a62e7bc09b899f7692c694360be7db93ebe44428d6605fccda244692"},
+    {file = "ovh-0.5.0.tar.gz", hash = "sha256:f74d190c4bff0953d76124cb8ed319a8a999138720e42957f0db481ef4746ae8"},
+]
 packaging = [
     {file = "packaging-20.9-py2.py3-none-any.whl", hash = "sha256:67714da7f7bc052e064859c05c595155bd1ee9f69f76557e21f051443c20947a"},
     {file = "packaging-20.9.tar.gz", hash = "sha256:5b327ac1320dc863dca72f4514ecc086f31186744b84a230374cc1fd776feae5"},
@@ -447,6 +474,10 @@ pyyaml = [
     {file = "PyYAML-5.4.1-cp39-cp39-win_amd64.whl", hash = "sha256:c20cfa2d49991c8b4147af39859b167664f2ad4561704ee74c1de03318e898db"},
     {file = "PyYAML-5.4.1.tar.gz", hash = "sha256:607774cbba28732bfa802b54baa7484215f530991055bb562efbed5b2f20a45e"},
 ]
+redis = [
+    {file = "redis-3.5.3-py2.py3-none-any.whl", hash = "sha256:432b788c4530cfe16d8d943a09d40ca6c16149727e4afe8c2c9d5580c59d9f24"},
+    {file = "redis-3.5.3.tar.gz", hash = "sha256:0e7e0cfca8660dea8b7d5cd8c4f6c5e29e11f31158c0b0ae91a397f00e5a05a2"},
+]
 six = [
     {file = "six-1.16.0-py2.py3-none-any.whl", hash = "sha256:8abb2f1d86890a2dfb989f9a77cfcfd3e47c2a354b01111771326f8aa26e0254"},
     {file = "six-1.16.0.tar.gz", hash = "sha256:1e61c37477a1626458e36f7b1d82aa5c9b094fa4802892072e49de9c60c4c926"},

pyproject.toml

@@ -8,6 +8,8 @@ authors = ["Gabriel Augendre <gabriel@augendre.info>"]
 python = "^3.9"
 dnspython = "^2.1.0"
 Flask = "^2.0.0"
+ovh = "^0.5.0"
+redis = "^3.5.3"
 
 [tool.poetry.dev-dependencies]
 pytest = "^5.2"

shortener/api_connectors/base_api_connector.py

@@ -0,0 +1,6 @@
+from shortener.data_structures import UserInput
+
+
+class BaseApiConnector:
+    def add_record(self, user_input: UserInput) -> None:
+        raise NotImplementedError("Subclasses must implement add_record")

shortener/api_connectors/ovh/ovh_api.py

@@ -0,0 +1,38 @@
+import os
+
+import ovh
+from ovh import HTTPError, InvalidResponse
+
+from shortener.api_connectors.base_api_connector import BaseApiConnector
+from shortener.data_structures import UserInput
+from shortener.exceptions import ApiException
+
+
+class OvhApi(BaseApiConnector):
+    def __init__(self):
+        endpoint = os.environ["OVH_ENDPOINT"]
+        application_key = os.environ["OVH_APPLICATION_KEY"]
+        application_secret = os.environ["OVH_APPLICATION_SECRET"]
+        consumer_key = os.environ["OVH_CONSUMER_KEY"]
+        self._base_domain = os.environ["BASE_DOMAIN"]
+        self._client = ovh.Client(
+            endpoint=endpoint,
+            application_key=application_key,
+            application_secret=application_secret,
+            consumer_key=consumer_key,
+        )
+
+    def add_record(self, user_input: UserInput) -> None:
+        try:
+            self._add_record(user_input)
+        except (HTTPError, InvalidResponse) as e:
+            raise ApiException(message=str(e))
+
+    def _add_record(self, user_input: UserInput) -> None:
+        self._client.post(
+            f"/domain/zone/{self._base_domain}/record",
+            fieldType="TXT",
+            subDomain=user_input.short_code,
+            target=user_input.url,
+        )
+        self._client.post(f"/domain/zone/{self._base_domain}/refresh")

shortener/cache.py

@@ -0,0 +1,8 @@
+import os
+
+import redis
+
+REDIS_HOST = os.getenv("REDIS_HOST", "localhost")
+REDIS_PORT = int(os.getenv("REDIS_PORT", 6379))
+REDIS_DB = int(os.getenv("REDIS_DB", 0))
+cache = redis.Redis(host=REDIS_HOST, port=REDIS_PORT, db=REDIS_DB)

shortener/data_structures.py

@@ -0,0 +1,13 @@
+from dataclasses import dataclass
+
+from flask import request
+
+
+@dataclass
+class UserInput:
+    short_code: str
+    url: str
+
+    @property
+    def short_url(self):
+        return f"{request.host_url}{self.short_code}"

shortener/exceptions.py

@@ -7,3 +7,7 @@ class ApiException(Exception):
 class BadRequestException(ApiException):
     def __init__(self, message="Bad request", code=400):
         super().__init__(message, code)
+
+
+class ShortCodeNotFoundException(Exception):
+    pass

shortener/handlers.py

@@ -1,27 +1,72 @@
+import os
+from typing import Dict
+from urllib.parse import urlparse
+
 from flask import request
 
-from shortener.exceptions import BadRequestException
+from shortener.api_connectors.base_api_connector import BaseApiConnector
-from shortener.ovh.ovh_api import OvhApi
+from shortener.api_connectors.ovh.ovh_api import OvhApi
+from shortener.cache import cache
+from shortener.data_structures import UserInput
+from shortener.exceptions import BadRequestException, ShortCodeNotFoundException
+from shortener.resolver import resolver
 
-SUPPORTED_PROVIDERS = {"ovh": OvhApi}
+SUPPORTED_PROVIDERS: Dict[str, type] = {"ovh": OvhApi}
-
+PROVIDER_NAME = os.environ["PROVIDER"].lower()
-
+PROVIDER_CLASS = SUPPORTED_PROVIDERS[PROVIDER_NAME]
-def handle_expand(shortcode, resolver):
+COOLDOWN = "cooldown"
-    answer = resolver.resolve(shortcode, "TXT", search=True, lifetime=10)
-    redirect_url = list(answer)[0].strings[0].decode("utf-8")
-    return redirect_url
 
 
 def handle_shorten():
-    user_input = request.json
+    user_input: UserInput = _validate_user_input()
-    print(user_input)
+    cooldown = cache.get(user_input.short_code)
-    provider = user_input.get("provider")
+    if cooldown:
-    if not provider:
-        raise BadRequestException(message="`provider` is required")
-    provider_class = SUPPORTED_PROVIDERS.get(provider)
-    if not provider_class:
-        supported_providers = list(SUPPORTED_PROVIDERS.keys())
         raise BadRequestException(
-            message=f"`provider` is not supported. Must be one of {supported_providers}"
+            message=f"Please wait before submitting again for {user_input.short_code}."
         )
-    return {"status": "ok"}
+    provider: BaseApiConnector = _get_provider()
+    provider.add_record(user_input)
+    cache.set(user_input.short_code, COOLDOWN, ex=90)
+    return {"status": "ok", "url": user_input.short_url}
+
+
+def _validate_user_input():
+    user_input = request.json
+    if not user_input:
+        user_input = request.form
+    url = user_input.get("url")
+    if not url:
+        raise BadRequestException(message="`url` is required")
+    parsed_url = urlparse(url)
+    if not all([parsed_url.scheme, parsed_url.netloc]):
+        raise BadRequestException(
+            message="`url` doesn't seem well formatted. "
+            "Please include at least protocol and domain name. "
+            "E.g. 'https://google.com' instead of 'google.com'."
+        )
+
+    short_code = user_input.get("short_code")
+    if not short_code:
+        raise BadRequestException(message="`short_code` is required")
+    short_code = str(short_code)
+    if len(short_code) < 4:
+        raise BadRequestException(
+            message="`short_code` must be longer than 4 characters."
+        )
+    if _short_code_exists(short_code):
+        raise BadRequestException(message=f"`{short_code}` is already taken")
+
+    user_input = UserInput(short_code=short_code, url=url)
+    return user_input
+
+
+def _get_provider() -> BaseApiConnector:
+    return PROVIDER_CLASS()
+
+
+def _short_code_exists(short_code):
+    try:
+        resolver.resolve_shortcode(short_code)
+        return True
+    except ShortCodeNotFoundException:
+        return False

shortener/main.py

@@ -1,39 +1,40 @@
 import os
 
-from dns.name import from_text
+from flask import Flask, redirect, render_template, request
-from dns.resolver import LRUCache, Resolver
-from flask import Flask, redirect
 
-from shortener.exceptions import ApiException
+from shortener.exceptions import ApiException, ShortCodeNotFoundException
-from shortener.handlers import handle_expand, handle_shorten
+from shortener.handlers import handle_shorten
-
+from shortener.resolver import resolver
-BASE_DOMAIN = os.getenv("BASE_DOMAIN")
 
 app = Flask(__name__)
-resolver = Resolver()
-resolver.search = [from_text(BASE_DOMAIN)]
-resolver.cache = LRUCache()
 
 
 @app.route("/")
 def home():
-    return "<p>Welcome to the url shortener!</p>"
+    return render_template("welcome.html")
 
 
-@app.route("/shorten/", methods=["POST"])
+@app.route("/shorten", methods=["POST"])
 def shorten_url():
     try:
-        return handle_shorten()
+        result = handle_shorten()
+        code = 200
     except ApiException as e:
-        return {"status": "error", "message": e.message}, e.code
+        result = {"message": e.message, "status": "error"}
+        code = e.code
+    is_api = bool(request.json)
+    if is_api:
+        return result, code
+
+    return render_template("result.html", **result), code
 
 
-@app.route("/<string:shortcode>/")
+@app.route("/<string:shortcode>")
 def expand_url(shortcode: str):
     try:
-        redirect_url = handle_expand(shortcode, resolver)
+        redirect_url = resolver.resolve_shortcode(shortcode)
-    except:
+    except ShortCodeNotFoundException:
-        return "<p>URL not found</p>"
+        return render_template("not_found.html")
     return redirect(redirect_url, code=302)
 
 

shortener/ovh/ovh_api.py

@@ -1,2 +0,0 @@
-class OvhApi:
-    pass

shortener/resolver.py

@@ -0,0 +1,26 @@
+import os
+
+from dns.name import from_text
+from dns.resolver import LRUCache, Resolver
+
+from shortener.exceptions import ShortCodeNotFoundException
+
+BASE_DOMAIN = os.getenv("BASE_DOMAIN")
+
+
+class ShortenerResolver(Resolver):
+    def __init__(self):
+        super().__init__()
+        self.search = [from_text(BASE_DOMAIN + ".")]
+        self.cache = LRUCache()
+
+    def resolve_shortcode(self, shortcode):
+        try:
+            answer = self.resolve(shortcode, "TXT", search=True, lifetime=10)
+            redirect_url = list(answer)[0].strings[0].decode("utf-8")
+            return redirect_url
+        except:
+            raise ShortCodeNotFoundException()
+
+
+resolver = ShortenerResolver()

shortener/templates/base.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>URL shortener</title>
+</head>
+<body>
+{% block content %}
+{% endblock %}
+</body>
+</html>

shortener/templates/not_found.html

@@ -0,0 +1,7 @@
+{% extends "base.html" %}
+
+{% block content %}
+    <h1>URL not found</h1>
+    <p>If you recently created the redirect, please wait a couple of minutes for DNS to propagate.</p>
+    <p>If you've been sent this URL, please contact the sender. It's likely there's an issue with the URL you received.</p>
+{% endblock %}

shortener/templates/result.html

@@ -0,0 +1,22 @@
+{% extends "base.html" %}
+
+{% block content %}
+    <h1>Result</h1>
+    <p class="status-{{ status }}">Status: {{ status }}</p>
+    {% if message %}
+        <p>{{ message }}</p>
+    {% endif %}
+    {% if url %}
+        <p>
+            Your short URL is: <a href="{{ url }}">{{ url }}</a>.<br>
+            Please wait a couple of minutes for DNS to propagate before testing and
+            sharing this URL.
+        </p>
+    {% endif %}
+    <p>
+        <a onclick="window.history.back(); return false;"
+           href="{{ url_for("home") }}">
+            Go back
+        </a>
+    </p>
+{% endblock %}

shortener/templates/welcome.html

@@ -0,0 +1,14 @@
+{% extends "base.html" %}
+
+{% block content %}
+    <h1>Welcome!</h1>
+    <p>Welcome to the URL shortener.</p>
+    <form action="{{ url_for("shorten_url") }}" method="post">
+        <label for="short_code">Short code</label>
+        <input type="text" name="short_code" id="short_code">
+        <label for="url">Url to shorten</label>
+        <input type="text" name="url" id="url">
+        <button type="submit">Submit</button>
+        <button type="reset">Reset</button>
+    </form>
+{% endblock %}