Python Support?

[alhazmy13]

I'm wondering if this plugin support Python functions or not, because it's seems not working in my project (Python based)

[alhazmy13]

Ok, it works but I think the log for the function is not working, I'll figure out how I can solve it

[fariedt]

@alhazmy13 can you please share your serverless.yaml file? I cannot seem to figure out how to call Python lambdas with this plugin's config.

If I do

custom:
  dynamodbStream:
    host: localhost
    port: 8000
    region: us-east-2
    pollForever: boolean
    streams:
      - table: roomTable
        functions:
          - readstream

with handler as a function in stream.py:

functions:
  readstream:
    handler: stream.handler
    environment:
      foo: bar
    events:
      - stream:
          enabled: true
          type: dynamodb
          batchSize: 1
          startingPosition: LATEST
          arn:
            Fn::GetAtt: [roomTable, StreamArn]

I get this error:

DynamoDBStreamReadable error... terminating stream... Error => Error: Cannot find module '/home/fn/serverless-dev/stream'
 
  Error --------------------------------------------------
 
  Error: Cannot find module '/home/fn/serverless-dev/stream'
      at Function.Module._resolveFilename (internal/modules/cjs/loader.js:636:15)
      at Function.resolve (internal/modules/cjs/helpers.js:33:19)
[...]

If I change the custom section to say instead

    streams:
      - table: roomTable
        functions:
          - stream.handler

I get this exception:

DynamoDBStreamReadable error... terminating stream... Error => TypeError: Cannot read property 'environment' of undefined
 
  Type Error ---------------------------------------------
 
  TypeError: Cannot read property 'environment' of undefined
      at createHandler (/home/fn/serverless-dev/node_modules/serverless-plugin-offline-dynamodb-stream/src/executeFunctions.js:17:51)
      at Promise.all.map (/home/fn/serverless-dev/node_modules/serverless-plugin-offline-dynamodb-stream/src/executeFunctions.js:45:23)

[vlade11115]

@fariedt any updates or follow-ups on this? I got same error when i try to use serverless-plugin-offline-dynamodb-stream and python offline lambda function.

[alhazmy13]

Hi @vlade11115 after too many tests, I found this plugin is not working at all with Python even if there's no error, the invocation is buggy

[mcopik]

Similar problem here: I'm trying to run Python function on new events in DynamoDB, execution triggers the following exception:

  Error: Cannot find module '/home/mcopik/project/aws/writer'
  Require stack:
  - /home/mcopik/project/node_modules/serverless-plugin-offline-dynamodb-stream/src/executeFunctions.js
  - /home/mcopik/project/node_modules/serverless-plugin-offline-dynamodb-stream/src/FunctionExecutable.js
  - /home/mcopik/project/node_modules/serverless-plugin-offline-dynamodb-stream/src/index.js
  - /home/mcopik/project/node_modules/serverless/lib/classes/PluginManager.js
  - /home/mcopik/project/node_modules/serverless/lib/Serverless.js
  - /home/mcopik/project/python-venv/lib/node_modules/serverless/lib/Serverless.js
  - /home/mcopik/project/python-venv/lib/node_modules/serverless/scripts/serverless.js
  - /home/mcopik/project/python-venv/lib/node_modules/serverless/bin/serverless.js

The configuration looks like this:

custom:
  serverless-offline:
    host: 0.0.0.0
    port: 4000
    dontPrintOutput: false
  dynamodb:
    start:
      port: 8000
      migrate: true
      noStart: false
    stages:
      - ${self:provider.stage}
  dynamodbStream:
    host: localhost
    port: 8000
    region: localhost
    streams:
      - table: ${self:provider.environment.DYNAMODB_TABLE}-write-queue
        functions:
          - writer

functions:
  writer:
    handler: aws/writer.handler

However, looking at the source code I can find only support for Node.js modules?

[mdrijwan]

not working with python as in january 2021!