Error response from daemon: Dockerfile parse error line 1: unknown instruction: #

Question

Im new to docker and trying to learn it. Im following this tutorial: https://docs.docker.com/get-started/part2/#apppy

So I installed Docker on Windows. Created 3 fil

Answer 1

I forgot to have a whitespace in ENTRYPOINT["java",

It should be ENTRYPOINT ["java",

Answer 2

In Google Cloud Platform in console project using nano the comand work for me
1º-nano
2-

# The Dockerfile defines the image's environment
# Import Python runtime and set up working directory
FROM python:2.7-alpine
WORKDIR /app
ADD . /app

# Install any necessary dependencies
RUN pip install -r requirements.txt

# Open port 80 for serving the webpage
EXPOSE 80

# Run app.py when the container launches
CMD ["python", "app.py"]

save the file...

Answer 3

I just tested the same and by default VSCode seems to save the Dockerfile with UTF-16 LE encoding.

Resaving the file as UTF-8 allowed docker build to run without error.

Answer 4

Solved by removing the dockerfile and creating it with Notepad instead of Visual Code

Answer 5

When doing it from Windows, I had to make sure that I have line breaks in my Dockerfile configured for Linux (LF) and not for Windows (CRLF) when editing it from a text editor.

Answer 6

I experienced this issue when working on a React app setup on Docker.

Sending build context to Docker daemon 1.143MB

Error response from daemon: Dockerfile parse error line 1: unknown instruction: +#

Here's how I solved it

The issue was that I had another file named Dockerfile (capital case D) which had some instructions in it, and it was conflicting with the original dockerfile (lower case d) in my project root directory.

I fixed this by deleting the Dockerfile and running the command:

docker build t myapp:latest .

to build the docker image from the dockerfile instead.

That's all.

I hope this helps