Dockerfile: allow specifying s3gw directory

When requiring the copy of the `entrypoint.sh` script, we did not
account for actions on other repositories relying on checking out the
`s3gw.git` repository and building images using the Dockerfile from
within an `s3gw` directory. This causes the script to not be found,
because it's instead in `s3gw/tools/entrypoint.sh`, versus what we
expected, `tools/entrypoint.sh`.

This helps addressing that by allowing the caller to specify on which
directory we can find the s3gw repository.

Signed-off-by: Joao Eduardo Luis <[email protected]>

Dockerfile

@@ -45,8 +45,9 @@ ENV LD_LIBRARY_PATH=/s3gw/lib:$LD_LIBRARY_PATH
 FROM s3gw-base as buildenv
 
 ARG CMAKE_BUILD_TYPE=Debug
+ARG SRC_CEPH_DIR=./ceph
 
-ENV SRC_CEPH_DIR="${SRC_CEPH_DIR:-"./ceph"}"
+ENV SRC_CEPH_DIR=${SRC_CEPH_DIR}
 ENV ENABLE_GIT_VERSION=OFF
 
 # Needed for extra build deps
@@ -189,6 +190,8 @@ ARG QUAY_EXPIRATION=Never
 ARG S3GW_VERSION=Development
 ARG S3GW_ID=s3gw
 
+ARG SRC_S3GW_DIR=.
+
 ENV S3GW_ID=${S3GW_ID}
 ENV S3GW_DNS_NAME=""
 ENV S3GW_DEBUG="none"
@@ -208,7 +211,7 @@ COPY --from=buildenv [ \
     "/srv/ceph/build/lib/libceph-common.so.2", \
     "/s3gw/lib/" ]
 
-COPY tools/entrypoint.sh /s3gw/bin/
+COPY ${SRC_S3GW_DIR}/tools/entrypoint.sh /s3gw/bin/
 
 # ports for S3 endpoints
 #  http:  7480