Testing Api Gateway endpoint locally returning `No response from invoke container` and `Invalid lambda response received` in Dockerised sam app

Description:

I’m dockerising sam app. When accessing api endpoint for HelloWorld locally, it responds with No response from invoke container for HelloWorldFunction and Invalid lambda response received: Lambda response must be valid json.

It works fine whithout dockerisation.

Steps to reproduce:

Dockerfile

FROM ruby:2.7.0-alpine

RUN apk add --update --no-cache \
    build-base \
    postgresql-dev \
    postgresql-client \
    python3 \
    py3-pip \
    util-linux \
    python3-dev

RUN pip3 install aws-sam-cli

ARG USER
ARG HOME
ARG UID

RUN apk add --update \
    sudo

RUN echo "Welcome home: $USER => $UID"

RUN adduser -S -D -G users -u $UID $USER
RUN addgroup -S sudo
RUN echo "%sudo ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/sudo 
RUN adduser $USER sudo

RUN echo "Welcome home: $USER"

WORKDIR ${HOME}

EXPOSE 3001

ENTRYPOINT ["sh", "./entrypoint.sh"]

docker-compose.yml

version: '3.8'
services:
  sam_app:
    build:
      context: ./sam-app
      args:
        - HOME
        - USER
        - UID
    user: "${UID}:100"
    command: ["$PWD"]
    ports:
      - "3001:3001"
    volumes:
      - ./sam-app:$HOME
      - /var/run/docker.sock:/var/run/docker.sock

Entrypoint.sh

BASEDIR="$1"

echo "Basedir => ${BASEDIR}"

sudo sam local start-api \
  --template ./template.yaml \
  --host 0.0.0.0 \
  --port 3001 \
  --docker-volume-basedir "${BASEDIR}/sam-app/" \
  --docker-network drink_default \
  --debug

hello_world/app.rb

def lambda_handler(event:, context:)
  {
    statusCode: 200,
    body: {
      message: "Hello World!",
      # location: response.body
    }.to_json
  }
end

Observed result:

am_app_1  | 2020-12-21 01:31:22,493 | Constructed String representation of Event to invoke Lambda. Event: {"body": null, "headers": {"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9", "Accept-Encoding": "gzip, deflate, br", "Accept-Language": "en-GB,en;q=0.9", "Connection": "keep-alive", "Host": "localhost:3001", "Sec-Fetch-Dest": "document", "Sec-Fetch-Mode": "navigate", "Sec-Fetch-Site": "none", "Sec-Fetch-User": "?1", "Upgrade-Insecure-Requests": "1", "User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36", "X-Forwarded-Port": "3001", "X-Forwarded-Proto": "http"}, "httpMethod": "GET", "isBase64Encoded": false, "multiValueHeaders": {"Accept": ["text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9"], "Accept-Encoding": ["gzip, deflate, br"], "Accept-Language": ["en-GB,en;q=0.9"], "Connection": ["keep-alive"], "Host": ["localhost:3001"], "Sec-Fetch-Dest": ["document"], "Sec-Fetch-Mode": ["navigate"], "Sec-Fetch-Site": ["none"], "Sec-Fetch-User": ["?1"], "Upgrade-Insecure-Requests": ["1"], "User-Agent": ["Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36"], "X-Forwarded-Port": ["3001"], "X-Forwarded-Proto": ["http"]}, "multiValueQueryStringParameters": null, "path": "/hello", "pathParameters": null, "queryStringParameters": null, "requestContext": {"accountId": "123456789012", "apiId": "1234567890", "domainName": "localhost:3001", "extendedRequestId": null, "httpMethod": "GET", "identity": {"accountId": null, "apiKey": null, "caller": null, "cognitoAuthenticationProvider": null, "cognitoAuthenticationType": null, "cognitoIdentityPoolId": null, "sourceIp": "172.22.0.1", "user": null, "userAgent": "Custom User Agent String", "userArn": null}, "path": "/hello", "protocol": "HTTP/1.1", "requestId": "dd99d1bb-cc40-42f8-a2f2-eeefcc22d111", "requestTime": "21/Dec/2020:01:30:38 +0000", "requestTimeEpoch": 1608514238, "resourceId": "123456", "resourcePath": "/hello", "stage": "Prod"}, "resource": "/hello", "stageVariables": null, "version": "1.0"}
sam_app_1  | 2020-12-21 01:31:22,493 | Found one Lambda function with name 'HelloWorldFunction'
sam_app_1  | 2020-12-21 01:31:22,494 | Invoking app.lambda_handler (ruby2.7)
sam_app_1  | 2020-12-21 01:31:22,494 | No environment variables found for function 'HelloWorldFunction'
sam_app_1  | 2020-12-21 01:31:22,494 | Environment variables overrides data is standard format
sam_app_1  | 2020-12-21 01:31:22,494 | Loading AWS credentials from session with profile 'None'
sam_app_1  | 2020-12-21 01:31:24,549 | Resolving code path. Cwd=/home/sameer/projects/drink/sam-app/, CodeUri=hello_world/
sam_app_1  | 2020-12-21 01:31:24,549 | Resolved absolute path to code is /home/sameer/projects/drink/sam-app/hello_world
sam_app_1  | 2020-12-21 01:31:24,550 | Code /home/sameer/projects/drink/sam-app/hello_world is not a zip/jar file
sam_app_1  | 2020-12-21 01:31:24,574 | Skip pulling image and use local one: amazon/aws-sam-cli-emulation-image-ruby2.7:rapid-1.15.0.
sam_app_1  | 
sam_app_1  | 2020-12-21 01:31:24,574 | Mounting /home/sameer/projects/drink/sam-app/hello_world as /var/task:ro,delegated inside runtime container
sam_app_1  | 2020-12-21 01:31:25,386 | Starting a timer for 3 seconds for function 'HelloWorldFunction'
sam_app_1  | 2020-12-21 01:31:26,707 | Cleaning all decompressed code dirs
sam_app_1  | 2020-12-21 01:31:26,707 | No response from invoke container for HelloWorldFunction
sam_app_1  | 2020-12-21 01:31:26,707 | Invalid lambda response received: Lambda response must be valid json
sam_app_1  | 2020-12-21 01:31:26 172.22.0.1 - - [21/Dec/2020 01:31:26] "GET /hello HTTP/1.1" 502 -
sam_app_1  | 2020-12-21 01:31:26 172.22.0.1 - - [21/Dec/2020 01:31:26] "GET /favicon.ico HTTP/1.1" 403 -

Expected result:

Json output on browser {message: “hello world”}

Additional environment details (Ex: Windows, Mac, Amazon Linux etc)

1. OS: ubuntu VERSION=“20.04.1 LTS (Focal Fossa)”
2. sam --version: 1.15.0
3. Homebrew: VERSION=“2.6.2”
4. docker: VERSION=“19.03.8”

Add --debug flag to command you are running

[jfuss]

@alliesground SAM CLI is meant to be run from your machine and interact with docker, not run SAM CLI within Docker. My suggestion here is to do that instead of Dockerize.

What’s the use case on wanting to do this? Why do you need to be running docker within docker?

[xiaoxinghu]

Another common use case for dockerizing sam: CI pipelines. Like @jasonterando said, it’s a pain to maintain packages/tools installed on build agents. Different teams need their tools in particular ways. It’s more like dependencies for your projects. The tools break over time, so you need to keep your setup predictable. That’s what docker provides. If it’s “not a good idea” to use sam within docker, then I run out of ideas to make my CI pipeline stable over long period of time. I can’t trust my scripts/code to still work 1 year from now, after countless patching/upgrading of the build agents. Not to mention that normally it’s not easy to tweak infrastructure setups within big corporates, it’s a long and risky process. Sometimes impossible (e.g. they refuse to install arbitrary software on agents, because they gave you docker already).