i am not able execute next commands after localstack --host command - amazon-web-services

Question

FROM ubuntu:18.04
RUN apt-get update -y && \
apt-get install -y apt-utils && \
apt-get install -y python3-pip python3-dev\
pypy-setuptools
COPY . .
WORKDIR .
RUN pip3 install boto3
RUN pip3 install awscli
RUN apt-get install libsasl2-dev
ENV HOST_TMP_FOLDER=/tmp/localstack
RUN apt-get install -y git
RUN apt-get install -y npm
RUN mkdir -p .localstacktmp
ENV TMPDIR=.localstacktmp
RUN pip3 install localstack[full]
RUN SERVICES=s3,lambda,es DEBUG=1 localstack start --host
WORKDIR ./boto3Tools
ENTRYPOINT [ "python3" ]
CMD [ "script.py" ]

Answer 1

You can't start services in a Dockerfile.
In your case what's happening is that your Dockerfile is running RUN localstack start. That goes ahead and starts up the selected set of services and stays running, waiting for connections. Meanwhile, the Dockerfile is waiting for the command you launched to finish before it moves on.
The usual answer to this is to start servers and clients in separate containers (or start a server in a container and run clients directly from your host). In this case, there is already a localstack/localstack Docker image and a prebuilt Docker Compose setup, so you can just run it:
curl -LO https://github.com/localstack/localstack/raw/master/docker-compose.yml
docker-compose up
The localstack GitHub repo has more information on using it.
If you wanted to use a Boto-based application with this, the easiest way is to add it to the same docker-compose.yml file (or, conversely, add Localstack to the Compose setup you already have). At this point you can use normal Docker inter-container communication to reach the mock AWS, but you have to configure this in your code
s3 = boto3.client('s3',
endpoint_url='http://localstack:4566')
You have to make similar changes anyways to use localstack, so the only difference is the hostname you're setting.