Use AIRFLOW_CONSTRAINTS_LOCATION when passed during docker build (#12604

)

Previously, even though this was passed during docker build it was
ignored. This commit fixes it

(cherry picked from commit c457c97)

Dockerfile

@@ -176,7 +176,7 @@ RUN if [[ ${AIRFLOW_PRE_CACHED_PIP_PACKAGES} == "true" ]]; then \
        fi; \
        pip install --user \
           "https://github.com/${AIRFLOW_REPO}/archive/${AIRFLOW_BRANCH}.tar.gz#egg=apache-airflow[${AIRFLOW_EXTRAS}]" \
-          --constraint "https://raw.githubusercontent.com/apache/airflow/${AIRFLOW_CONSTRAINTS_REFERENCE}/constraints-${PYTHON_MAJOR_MINOR_VERSION}.txt" \
+          --constraint "${AIRFLOW_CONSTRAINTS_LOCATION}" \
           && pip uninstall --yes apache-airflow; \
     fi
 

Dockerfile.ci

@@ -245,8 +245,8 @@ ENV AIRFLOW_EXTRAS=${AIRFLOW_EXTRAS}${ADDITIONAL_AIRFLOW_EXTRAS:+,}${ADDITIONAL_
 RUN echo "Installing with extras: ${AIRFLOW_EXTRAS}."
 
 ARG AIRFLOW_CONSTRAINTS_REFERENCE="constraints-master"
-ARG AIRFLOW_CONSTRAINTS_URL="https://raw.githubusercontent.com/apache/airflow/${AIRFLOW_CONSTRAINTS_REFERENCE}/constraints-${PYTHON_MAJOR_MINOR_VERSION}.txt"
-ENV AIRFLOW_CONSTRAINTS_URL=${AIRFLOW_CONSTRAINTS_URL}
+ARG AIRFLOW_CONSTRAINTS_LOCATION="https://raw.githubusercontent.com/apache/airflow/${AIRFLOW_CONSTRAINTS_REFERENCE}/constraints-${PYTHON_MAJOR_MINOR_VERSION}.txt"
+ENV AIRFLOW_CONSTRAINTS_LOCATION=${AIRFLOW_CONSTRAINTS_LOCATION}
 
 # By changing the CI build epoch we can force reinstalling Airflow from the current master
 # It can also be overwritten manually by setting the AIRFLOW_CI_BUILD_EPOCH environment variable.
@@ -269,11 +269,10 @@ ENV INSTALL_AIRFLOW_VIA_PIP=${INSTALL_AIRFLOW_VIA_PIP}
 RUN if [[ ${AIRFLOW_PRE_CACHED_PIP_PACKAGES} == "true" ]]; then \
         pip install \
             "https://github.com/${AIRFLOW_REPO}/archive/${AIRFLOW_BRANCH}.tar.gz#egg=apache-airflow[${AIRFLOW_EXTRAS}]" \
-                --constraint "https://raw.githubusercontent.com/apache/airflow/${AIRFLOW_CONSTRAINTS_REFERENCE}/constraints-${PYTHON_MAJOR_MINOR_VERSION}.txt" \
+                --constraint "${AIRFLOW_CONSTRAINTS_LOCATION}" \
                 && pip uninstall --yes apache-airflow; \
     fi
 
-
 # Generate random hex dump file so that we can determine whether it's faster to rebuild the image
 # using current cache (when our dump is the same as the remote onb) or better to pull
 # the new image (when it is different)
@@ -341,7 +340,7 @@ COPY scripts/in_container/entrypoint_ci.sh /entrypoint
 RUN chmod a+x /entrypoint
 
 # We can copy everything here. The Context is filtered by dockerignore. This makes sure we are not
-# copying over stuff that is accidentally generated or that we do not need (such as .egginfo)
+# copying over stuff that is accidentally generated or that we do not need (such as egg-info)
 # if you want to add something that is missing and you expect to see it in the image you can
 # add it with ! in .dockerignore next to the airflow, test etc. directories there
 COPY . ${AIRFLOW_SOURCES}/