psycopg2 文件夹压缩到 python venv lambda function

Question

I am trying to add the packages for psycopg2 into my zipped folder for my python lambda function. I am using Python version 3.8. Here is the psycopg2 documentation psycopg2 .

From these docs it seems like I have to pull the folder for psycopg2-3.8 into the zipped file for my lambda function. However, I cannot seem to get this to successfully run.

I am using a virtual environment and creating the zip file according to these AWS docs for virtual environment

To get the psycopg folder zipped I am running zip -g my-deployment-package.zip psycopg2

The error I am receiving is

{
  "errorMessage": "Unable to import module 'test': No module named 'psycopg2._psycopg'",
  "errorType": "Runtime.ImportModuleError"
}

Any help troubleshooting this would be great.

Answer 1

psycopg2-binary is a binary pip package of psycopg2 which comes with all dependencies and does not require compiling. To use it in your lambda function, you can create a lambda layer using docker as described in the AWS blog .

Thus you can add psycopg2-binary to your function as follows:

1. Create empty folder, eg mylayer .

2. Go to the folder and create requirements.txt file with the content of

psycopg2-binary

3. Run the following docker command:

The command will create layer for python3.8:

docker run -v "$PWD":/var/task "lambci/lambda:build-python3.8" /bin/sh -c "pip install -r requirements.txt -t python/lib/python3.8/site-packages/; exit"

4. Archive the layer as zip:

zip -9 -r mylayer.zip python 

5. Create lambda layer based on mylayer.zip in the AWS Console. Don't forget to specify Compatible runtime to python3.8 .

6. Add the the layer created in step 5 to your function.

7. I tested the layer using your code:

import psycopg2

def lambda_handler(event, context):
    
    print(dir(psycopg2))
    
    return "ok"

It works correctly :

['BINARY', 'Binary', 'DATETIME', 'DataError', 'DatabaseError', 'Date', 'DateFromTicks', 'Error', 'IntegrityError', 'InterfaceError', 'InternalError', 'NUMBER', 'NotSupportedError', 'OperationalError', 'ProgrammingError', 'ROWID', 'STRING', 'Time', 'TimeFromTicks', 'Timestamp', 'TimestampFromTicks', 'Warning', '__builtins__', '__cached__', '__doc__', '__file__', '__libpq_version__', '__loader__', '__name__', '__package__', '__path__', '__spec__', '__version__', '_connect', '_ext', '_json', '_psycopg', '_range', 'apilevel', 'compat', 'connect', 'errors', 'extensions', 'paramstyle', 'threadsafety', 'tz']

ps

The steps were execution on linux. If you don't have one you can create a linux ec2 instance and setup docker there if you are not sure how to modify the commands for Windows or Mac.