add docker buildx

Signed-off-by: Denis Baryshev <dennybaa@gmail.com>

runners/docker-remote.sh

@@ -2,11 +2,8 @@
 export CONTAINER_HOST=unix:///runner/podman.sock
 export DOCKER_HOST=unix:///runner/podman.sock
 
-## Ignore builder creation, not needed for buildah
 if [ "$1" = "buildx" ]; then
-  if [ "$#" -eq 1 ] || [ "$2" = "create" ]; then
-    echo "Compat mode: $0 $@"; exit 0
-  fi
+  shift; exec /runner/tools/bin/buildx "$@"
+else
+  exec /runner/tools/bin/podman --remote "$@"
 fi
-
-exec /runner/tools/bin/podman --remote "$@"

runners/podman.containerfile

@@ -8,6 +8,7 @@ ARG RUNNER_VERSION=""
 ARG PODMAN_VERSION="4.9.3"
 ARG CRUN_VERSION="1.14.4"
 ARG GH_CLI_VERSION="2.45.0"
+ARG BUILDX_VERSION="0.13.1"
 
 # Fetch deps
 RUN export DEBIAN_FRONTEND=noninteractive; apt-get -y update && apt-get install -y \
@@ -56,6 +57,10 @@ RUN mkdir -p /runner/tools/bin \
     # gh cli \
     && curl -fLo gh.tgz https://github.com/cli/cli/releases/download/v${GH_CLI_VERSION}/gh_${GH_CLI_VERSION}_linux_${TARGETARCH}.tar.gz \
     && tar -xzf gh.tgz && mv gh_${GH_CLI_VERSION}_linux_${TARGETARCH}/bin/gh /runner/tools/bin \
+    # docker buildx \
+    && curl -fLo /runner/tools/bin/buildx \
+        "https://github.com/docker/buildx/releases/download/v${BUILDX_VERSION}/buildx-v${BUILDX_VERSION}.linux-${TARGETARCH}" \
+    && chmod +x /runner/tools/bin/buildx \
     && rm -rf /tmp/*
 
 COPY --chmod=755 docker-compat.sh /usr/bin/docker