Replacing the placeholder API with a real one.

api/Dockerfile

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+FROM python:3
+
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1
+ENV PORT 8080
+ENV FLASK_APP app.py
+
+WORKDIR /app
+COPY . /app
+
+RUN pip install --no-cache -r requirements.txt
+
+CMD ["flask", "run", "-h", "0.0.0.0", "-p", "8080"]
+

api/app.py

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+import os
+import json
+from uuid import uuid4
+
+import boto3
+from flask import Flask, request
+
+
+APP_NAME = 'karaoke-http-api'
+VERSION = '0.10'
+PROCESSING_QUEUE_URL = os.getenv('PROCESSING_QUEUE_URL')
+TRACKS_TABLE_NAME = os.getenv('TRACKS_TABLE_NAME')
+UPLOAD_BUCKET_NAME = os.getenv('UPLOAD_BUCKET_NAME')
+UPLOAD_AUTH_TIMEOUT = int(os.getenv('UPLOAD_AUTH_TIMEOUT', 120))
+app = Flask(__name__)
+
+
+def get_dynamodb_client():
+    return boto3.client('dynamodb')
+
+
+def get_s3_client():
+    return boto3.client('s3')
+
+
+def get_sqs_client():
+    return boto3.client('sqs')
+
+
+def strip_dynamodb_type_tags(obj):
+    return {key: list(value.values())[0]
+        for key, value in obj.items()}
+
+
+@app.route('/')
+def info():
+    return dict(name=APP_NAME, version=VERSION)
+
+
+@app.route('/jobs', methods=['GET', 'POST'])
+def jobs_resource():
+    dynamodb = get_dynamodb_client()
+    if request.method == 'POST':
+        job_id = str(uuid4())
+
+        s3_key = f'track_{job_id}'
+        s3_complete_url = f's3://{UPLOAD_BUCKET_NAME}/{s3_key}'
+
+        dynamodb.put_item(
+            TableName=TRACKS_TABLE_NAME,
+            Item={
+                'id': {'S': job_id},
+                'input_s3_url': {'S': s3_complete_url},
+                'status': {'S': 'uploading'}
+            })
+
+        # create the pre-signed upload URL
+        s3 = get_s3_client()
+        upload_data = s3.generate_presigned_post(UPLOAD_BUCKET_NAME, s3_key,
+            Fields=None,
+            Conditions=None,
+            ExpiresIn=UPLOAD_AUTH_TIMEOUT)
+
+        return dict(job_id=job_id, upload_data=upload_data)
+
+    response = dynamodb.scan(TableName=TRACKS_TABLE_NAME)
+    return dict(items=[strip_dynamodb_type_tags(el) for el in response['Items']],
+                count=response['Count'],
+                scanned_count=response['ScannedCount'])
+
+
+@app.route('/jobs/<job_id>', methods=['GET'])
+def get_job_details(job_id):
+    dynamodb = get_dynamodb_client()
+    response = dynamodb.get_item(TableName=TRACKS_TABLE_NAME, Key={'id': {'S': job_id}})
+    return strip_dynamodb_type_tags(response['Item'])
+
+
+@app.route('/jobs/<job_id>/process', methods=['POST'])
+def trigger_job_processing(job_id):
+    dynamodb = get_dynamodb_client()
+    response = dynamodb.get_item(TableName=TRACKS_TABLE_NAME, Key={'id': {'S': job_id}})
+    job = strip_dynamodb_type_tags(response['Item'])
+
+    if job['status'] != 'uploading':
+        return dict(status='failed', message='Job is in a wrong state'), 400
+
+    dynamodb.update_item(
+        TableName=TRACKS_TABLE_NAME,
+        Key={'id': {'S': job_id}},
+        AttributeUpdates={
+            'status': {'Value': {'S': 'processing'}}
+        })
+
+    sqs = get_sqs_client()
+    response = sqs.send_message(
+        QueueUrl=PROCESSING_QUEUE_URL,
+        MessageBody=json.dumps({
+            'job_id': job['id'],
+            'input_s3_url': job['input_s3_url']}))
+
+    return dict(status='processing', message_id=response['MessageId'])

api/requirements.txt

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+flask
+boto3