Error response from daemon: No build stage in current context

Question

I was trying to run a container with kvm, using the code I found here: https://github.com/jessfraz/dockerfiles/tree/master/kvm I created a new directory, cd'd into it and created the dockerfile and start.sh files. When I gave order to build, it outputted the following error message:

Sending build context to Docker daemon  3.584kB
Error response from daemon: No build stage in current context

I have no idea what this means and I couldn't Google an answer. Any help?

Answer 1

Does your dockerfile have a: FROM repo/image

As the first line? I got this error when I forgot to specify the docker image that I was building from.

Even if you're building a "source image" you still need to specify FROM scratch as the first line of the dockerfile.

Answer 2

This usually happens because of the text that is written before the FROM command. Try removing the comments in your dockerfile and build again.

For reference https://github.com/moby/buildkit/issues/164

Answer 3

This message appears when you declare an environment variable (ENV) before declaring FROM.

For example:

# Define variables.
ARG PORT
ENV SERVER_PORT=$PORT

# Install minimal Python 3.
FROM python:3.7-alpine

# Install Python requirements.
COPY requirements.txt /
RUN pip install -r /requirements.txt

# Copy app source code.
COPY src/ /app
...

To resolve this, swap the declarations so that any environment variables are set after FROM.

# Install minimal Python 3.
FROM python:3.7-alpine

# Define variables.
ARG PORT
ENV SERVER_PORT=${PORT}

# Install Python requirements.
COPY requirements.txt /
RUN pip install -r /requirements.txt

# Copy app source code.
COPY src/ /app
...

Answer 4

According to the documentation on docs.docker.com, the first non-comment line of your Dockerfile must be the FROM line. To quote the docs:

The FROM instruction initializes a new build stage and sets the Base Image for subsequent instructions. As such, a valid Dockerfile must start with a FROM instruction.

Answer 5

I had the same issue! What helped me was to have the FROM command as the first command in file:

BAD:

MAINTAINER your name "[email protected]"
FROM dockerimagename

GOOD:

FROM dockerimagename
MAINTAINER your name "[email protected]"

Answer 6

The problem is resolved. When I went to dockerfile to edit the code I noticed that I accidentally uncommented the first line. Stupid mistake, I know. Thank you both for the help.

Answer 7

I do not think that this is your case, but it might help someone else with that error.

1. My Dockerfile ran without that error.
2. I added "FROM vcatechnology/linux-mint:18.2" to the start of the Dockerfile, no error either.
3. After deleting that FROM statement again, it was still searching for it, causing this error.
4. I could only get rid of the error by adding the FROM statement again.

Thus, this error can simply appear if you have used a Dockerfile starting with a FROM statement and if you then drop that FROM statement again.

Answer 8

In my case, I changed RUN to FROM.

Old Dockerfile:

RUN php:8-apache

COPY /src var/www/html/

ENV APACHE_DOCUMENT_ROOT ./src/public/

RUN sed -ri -e 's!/var/www/html!${APACHE_DOCUMENT_ROOT}!g' /etc/apache2/sites-available/*.conf

RUN sed -ri -e 's!/var/www/!${APACHE_DOCUMENT_ROOT}!g' /etc/apache2/apache2.conf /etc/apache2/conf-available/*.conf

EXPOSE 80

New Dockerfile:

FROM php:8-apache

COPY /src var/www/html/

ENV APACHE_DOCUMENT_ROOT ./src/public/

RUN sed -ri -e 's!/var/www/html!${APACHE_DOCUMENT_ROOT}!g' /etc/apache2/sites-available/*.conf

RUN sed -ri -e 's!/var/www/!${APACHE_DOCUMENT_ROOT}!g' /etc/apache2/apache2.conf /etc/apache2/conf-available/*.conf

EXPOSE 80

Answer 9

It was my case because I had ENV specified before FROM and as already mentioned, the FROM should be the first expression in your Dockerfile.

BUT

Since this PR https://github.com/moby/moby/pull/31352 you can specify ARG before FROM which might be suitable alternative for you.

So I've changed

ENV MY_VAR 1
FROM ...

to

ARG MY_VAR=1
FROM ...

---

BTW You can read about ARG vs ENV difference here https://vsupalov.com/docker-arg-vs-env/