Provide Mender client version as a argument to docker build

This way we could extend this argument to the user, but this is
not yet done.

Changelog: None

Signed-off-by: Mirza Krak <mirza.krak@northern.tech>

Dockerfile

@@ -52,9 +52,9 @@ RUN wget https://dl.google.com/go/go$GOLANG_VERSION.linux-amd64.tar.gz \
     && tar -C /usr/local -xzf go$GOLANG_VERSION.linux-amd64.tar.gz \
     && echo export PATH=$PATH:/usr/local/go/bin >> /root/.bashrc
 
-ENV MENDER_CLIENT_VERSION="1.6.0"
+ARG mender_client_version
 
-RUN echo "Cross-compiling Mender client $MENDER_CLIENT_VERSION"
+ENV MENDER_CLIENT_VERSION=$mender_client_version
 
 # NOTE: we are assuming generic ARM board here, needs to be extended later
 

docker-build

@@ -4,4 +4,6 @@ set -e
 
 IMAGE_NAME=mender-convert
 
-docker build . -t $IMAGE_NAME
+MENDER_CLIENT_VERSION="1.6.0"
+
+docker build . -t ${IMAGE_NAME} --build-arg mender_client_version=${MENDER_CLIENT_VERSION}