Fix dockerfile error

1. Make "bash" the default shell when building image
2. Add libarchive dependency for centos image

tools/docker/Dockerfile.aliyunlinux

@@ -7,6 +7,10 @@ FROM registry.cn-hangzhou.aliyuncs.com/alinux/aliyunlinux
 
 LABEL maintainer="Chunyang Hui <sanqian.hcy@antgroup.com>"
 
+#The default shell for the RUN instruction is ["/bin/sh", "-c"], which sometimes cause unexpected error
+#for example "source a_file". Use bash as default shell instead.
+SHELL ["/bin/bash", "-c"]
+
 RUN yum install -y --nogpgcheck \
         alinux-release-experimentals && \
         yum install -y --nogpgcheck \

tools/docker/Dockerfile.centos8.2

@@ -7,6 +7,11 @@ FROM centos:8.2.2004
 
 LABEL maintainer="He Sun <bochang.sh@antgroup.com>"
 
+#The default shell for the RUN instruction is ["/bin/sh", "-c"], which sometimes cause unexpected error
+#for example "source a_file". Use bash as default shell instead.
+SHELL ["/bin/bash", "-c"]
+
+# since cmake is updated to 3.18.2-9.el8, it must work with libarchive.
 RUN yum install epel-release -y && \
     dnf clean all && rm -r /var/cache/dnf && \
     dnf group install 'Development Tools' -y && \
@@ -24,6 +29,7 @@ RUN yum install epel-release -y && \
     gmp-devel \
     golang \
     jq \
+    libarchive \
     libcurl-devel \
     libmpc-devel \
     libxml2-devel \

tools/docker/Dockerfile.ubuntu18.04

@@ -9,6 +9,10 @@ FROM ubuntu:18.04
 
 LABEL maintainer="Qing Li <geding.lq@antgroup.com>"
 
+#The default shell for the RUN instruction is ["/bin/sh", "-c"], which sometimes cause unexpected error
+#for example "source a_file". Use bash as default shell instead.
+SHELL ["/bin/bash", "-c"]
+
 RUN apt-get update && DEBIAN_FRONTEND="noninteractive" apt-get install -y --no-install-recommends \
         alien \
         astyle \
@@ -160,6 +164,7 @@ ARG OCCLUM_BRANCH
 WORKDIR /root
 RUN git clone -b $OCCLUM_BRANCH https://github.com/occlum/occlum && \
     cd occlum && \
+    source /opt/intel/sgxsdk/environment && \
     make submodule && \
     OCCLUM_RELEASE_BUILD=1 make && \
     make install && \