CI: enable agent as init process and kata initrd tests

1. let travis build w/ and w/o agent as init process
2. test building kata initrd images

Signed-off-by: Peng Tao <bergwolf@gmail.com>

.travis.yml

@@ -9,11 +9,15 @@ dist: trusty
 
 language: bash
 
+env:
+  - AGENT_INIT=no
+  - AGENT_INIT=yes
+
 services:
   - docker
 
 before_script:
   - ".ci/setup.sh"
 
-script: 
+script:
 - "travis_wait .ci/run.sh"

tests/image_creation.bats

@@ -7,6 +7,7 @@
 
 rootfs_sh="$BATS_TEST_DIRNAME/../rootfs-builder/rootfs.sh"
 image_builder_sh="$BATS_TEST_DIRNAME/../image-builder/image_builder.sh"
+initrd_builder_sh="$BATS_TEST_DIRNAME/../initrd-builder/initrd_builder.sh"
 readonly tmp_dir=$(mktemp -t -d osbuilder-test.XXXXXXX)
 #FIXME: Remove image size after https://github.com/kata-containers/osbuilder/issues/25 is fixed
 readonly image_size=400
@@ -23,27 +24,50 @@ teardown(){
 	rm -rf "${tmp_dir}"
 }
 
-function build_image()
+function build_rootfs()
 {
 	distro="$1"
 	[ -n "$distro" ]
 	local rootfs="${tmp_dir}/rootfs-osbuilder"
 	sudo -E ${rootfs_sh} -r "${rootfs}" "${distro}"
-	sudo ${image_builder_sh} -s ${image_size} -o "${tmp_dir}/image.img" "${rootfs}"
+}
+
+function build_image()
+{
+	distro="$1"
+	[ -n "$distro" ]
+	local rootfs="${tmp_dir}/rootfs-osbuilder"
+	sudo -E ${image_builder_sh} -s ${image_size} -o "${tmp_dir}/image.img" "${rootfs}"
+}
+
+function build_initrd()
+{
+	distro="$1"
+	[ -n "$distro" ]
+	local rootfs="${tmp_dir}/rootfs-osbuilder"
+	sudo -E ${initrd_builder_sh} -o "${tmp_dir}/initrd-image.img" "${rootfs}"
 }
 
 @test "Can create fedora image" {
+	build_rootfs fedora
 	build_image fedora
+	build_initrd fedora
 }
 
 @test "Can create clearlinux image" {
+	build_rootfs clearlinux
 	build_image clearlinux
+	build_initrd clearlinux
 }
 
 @test "Can create centos image" {
-	build_image centos 
+	build_rootfs centos
+	build_image centos
+	build_initrd centos
 }
 
 @test "Can create euleros image" {
+	build_rootfs euleros
 	build_image euleros
+	build_initrd euleros
 }