add RPMBUILD_BASE_DIR to configure the base dir used for rpmbuild

Dockerfile

@@ -6,6 +6,8 @@ LABEL maintainer="Robert Kaussow <mail@geeklabor.de>" \
     org.label-schema.vendor="Robert Kaussow" \
     org.label-schema.schema-version="1.0"
 
+ENV RPMBUILD_BASE_DIR=/drone/src
+
 RUN yum install -q -y \
     dash \
     gcc gcc-c++ \
@@ -35,11 +37,12 @@ RUN yum install -q -y \
     yum-utils rpm-build rpmdevtools \
     epel-release && \
     rpm --import https://dl.fedoraproject.org/pub/epel/RPM-GPG-KEY-EPEL-7 && \
+    ln -s dash /bin/sh && \
     yum clean all
 
 ADD overlay/ /
 
 USER root
 
-WORKDIR /drone/src
+WORKDIR ${RPMBUILD_BASE_DIR}
 CMD []

README.md

@@ -6,18 +6,24 @@
 
 Simple Docker image based on CentOS 7 to build RPM packages.
 
+## Environment variables
+
+```Shell
+RPMBUILD_BASE_DIR=/drone/src
+```
+
 ## How to use
 
 There are two wrapper scripts around the rpmbuild command you could use:
 
-- `/bin/rpmbuild-official`: This will simply forward your command to the official binary at `/usr/bin/rpmbuild`
-- `/bin/rpmbuil`: This is a modified wrapper to prepare the environment before calling rpmbuil
+- `/usr/local/bin/rpmbuild-official`: This will simply forward your command to the official binary at `/usr/bin/rpmbuild`
+- `/usr/local/bin/rpmbuil`: This is a modified wrapper to prepare the environment before calling rpmbuil
 
-The wrapper `/bin/rpmbuil` will do the following:
+The wrapper `/usr/local/bin/rpmbuil` will do the following:
 
-- create `$(pwd)/dist`
-- create rpmbuild folder structure (`BUILDRPMS|SOURCES|SPECS|SRPMS`) under `$(pwd)/dist`
-- sync local patchfiles from `$(pwd)/patch` to `$(pwd)/dist/SOURCES`
+- create `$RPMBUILD_BASE_DIR/dist`
+- create rpmbuild folder structure (`BUILDRPMS|SOURCES|SPECS|SRPMS`) under `$RPMBUILD_BASE_DIR/dist`
+- sync local patchfiles from `$RPMBUILD_BASE_DIR/patch` to `$RPMBUILD_BASE_DIR/dist/SOURCES` if the `patch` folder exist
 - call `/bin/rpmbuil` with the given parameters
 
 ## License

overlay/usr/local/bin/rpmbuild

@@ -1,11 +1,14 @@
 #!/usr/bin/env sh
 set -eo pipefail
 
-DIR=$(pwd)
+mkdir -p "${RPMBUILD_BASE_DIR%/}/dist"
+mkdir -p "${RPMBUILD_BASE_DIR%/}/dist"
 
-mkdir -p ./dist
-echo '%_topdir '"${DIR%/}"'/dist' > /root/.rpmmacros
+echo '%_topdir '"${RPMBUILD_BASE_DIR%/}"'/dist' > /root/.rpmmacros
 rpmdev-setuptree
-rsync -q -av "${DIR%/}/patch/" "${DIR%/}/dist/SOURCES"
+
+if [ -d "$DIR" ]; then
+    rsync -q -av "${RPMBUILD_BASE_DIR%/}/patch/" "${RPMBUILD_BASE_DIR%/}/dist/SOURCES"
+fi
 
 exec /usr/bin/rpmbuild "$@"