rootfs: Create a summary file inside the image

Create a YAML metadata file inside the rootfs image
containing information about the environment:

```
/var/lib/osbuilder/osbuilder.yaml
```

Example contents:

```
---
osbuilder:
  url: "https://github.com/kata-containers/osbuilder"
  version: "unknown"
rootfs-creation-time: "2018-04-19T16:19:30.254610305+0000Z"
description: "osbuilder rootfs"
file-format-version: "0.0.1"
architecture: "x86_64"
base-distro:
  name: "Centos"
  version: "7"
  packages:
    - "iptables"
    - "systemd"
agent:
  url: "https://github.com/kata-containers/agent"
  name: "kata-agent"
  version: "0.0.1-2ec0b9593845b9a5e0eab5a85b20d74c35a2ca52-dirty"
  agent-is-init-daemon: "no"
```

This change adds a new `-o` option to `rootfs.sh` for
specifying the version of osbuilder to the rootfs builder.

Fixes #35.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>

.ci/setup.sh

@@ -14,12 +14,13 @@ bash "${cidir}/static-checks.sh"
 source /etc/os-release
 
 if [ "$ID" == fedora ];then
-	sudo -E dnf -y install automake  bats
+	sudo -E dnf -y install automake bats yamllint
 elif [ "$ID" == ubuntu ];then
 	#bats isn't available for Ubuntu trusty, need for travis
 	sudo add-apt-repository -y ppa:duggan/bats
 	sudo apt-get -qq update
-	sudo apt-get install -y -qq automake bats qemu-utils
+	sudo apt-get install -y -qq automake bats qemu-utils python-pip
+	sudo pip install yamllint
 else 
 	echo "Linux distribution not supported"
 fi

Makefile

@@ -10,10 +10,16 @@ DISTRO_ROOTFS := "$(PWD)/$(DISTRO)_rootfs"
 IMG_SIZE=500
 AGENT_INIT ?= no
 
+VERSION_FILE := ./VERSION
+VERSION := $(shell grep -v ^\# $(VERSION_FILE))
+COMMIT_NO := $(shell git rev-parse HEAD 2> /dev/null || true)
+COMMIT := $(if $(shell git status --porcelain --untracked-files=no),${COMMIT_NO}-dirty,${COMMIT_NO})
+VERSION_COMMIT := $(if $(COMMIT),$(VERSION)-$(COMMIT),$(VERSION))
+
 all: rootfs image initrd
 rootfs:
 	@echo Creating rootfs based on "$(DISTRO)"
-	"$(MK_DIR)/rootfs-builder/rootfs.sh" -r "$(DISTRO_ROOTFS)" "$(DISTRO)"
+	"$(MK_DIR)/rootfs-builder/rootfs.sh" -o $(VERSION_COMMIT) -r "$(DISTRO_ROOTFS)" "$(DISTRO)"
 
 image: rootfs image-only
 

VERSION

@@ -0,0 +1,2 @@
+# This is the version of osbuilder.
+0.0.1

image-builder/image_builder.sh

@@ -104,6 +104,7 @@ if [ -n "${USE_DOCKER}" ] ; then
 		--env AGENT_INIT=${AGENT_INIT} \
 		-v /dev:/dev \
 		-v "${script_dir}":"/osbuilder" \
+		-v "${script_dir}/../scripts":"/scripts" \
 		-v "${ROOTFS}":"/rootfs" \
 		-v "${IMAGE_DIR}":"/image" \
 		${image_name} \

rootfs-builder/rootfs.sh

@@ -49,6 +49,7 @@ $(get_distros)
 Options:
 -a  : agent version DEFAULT: ${AGENT_VERSION} ENV: AGENT_VERSION 
 -h  : Show this help message
+-o  : specify version of osbuilder
 -r  : rootfs directory DEFAULT: ${ROOTFS_DIR} ENV: ROOTFS_DIR
 
 ENV VARIABLES:
@@ -144,11 +145,14 @@ copy_kernel_modules()
 	OK "Kernel modules copied"
 }
 
-while getopts c:hr: opt
+OSBUILDER_VERSION="unknown"
+
+while getopts c:ho:r: opt
 do
 	case $opt in
 		a)	AGENT_VERSION="${OPTARG}" ;;
 		h)	usage ;;
+		o)	OSBUILDER_VERSION="${OPTARG}" ;;
 		r)	ROOTFS_DIR="${OPTARG}" ;;
 	esac
 done
@@ -161,6 +165,8 @@ shift $(($OPTIND - 1))
 
 [ -n "${KERNEL_MODULES_DIR}" ] && [ ! -d "${KERNEL_MODULES_DIR}" ] && die "KERNEL_MODULES_DIR defined but is not an existing directory"
 
+[ -z "${OSBUILDER_VERSION}" ] && die "need osbuilder version"
+
 distro="$1"
 
 [ -n "${distro}" ] || usage 1
@@ -214,6 +220,7 @@ if [ -n "${USE_DOCKER}" ] ; then
 		--env GOPATH="${GOPATH}" \
 		--env KERNEL_MODULES_DIR="${KERNEL_MODULES_DIR}" \
 		--env EXTRA_PKGS="${EXTRA_PKGS}" \
+		--env OSBUILDER_VERSION="${OSBUILDER_VERSION}" \
 		-v "${script_dir}":"/osbuilder" \
 		-v "${ROOTFS_DIR}":"/rootfs" \
 		-v "${script_dir}/../scripts":"/scripts" \
@@ -251,3 +258,6 @@ OK "Agent installed"
 info "Check init is installed"
 [ -x "${init}" ] || [ -L "${init}" ] || die "/sbin/init is not installed in ${ROOTFS_DIR}"
 OK "init is installed"
+
+info "Creating summary file"
+create_summary_file "${ROOTFS_DIR}"

scripts/lib.sh

@@ -126,3 +126,65 @@ build_rootfs()
 
 	[ -n "${ROOTFS_DIR}" ]  && rm -r "${ROOTFS_DIR}${CACHE_DIR}"
 }
+
+# Create a YAML metadata file inside the rootfs.
+#
+# This provides useful information about the rootfs than can be interrogated
+# once the rootfs has been converted into a image/initrd.
+create_summary_file()
+{
+	local -r rootfs_dir="$1"
+
+	[ -z "$rootfs_dir" ] && die "need rootfs"
+
+	local -r file_dir="/var/lib/osbuilder"
+	local -r dir="${rootfs_dir}${file_dir}"
+
+	local -r filename="osbuilder.yaml"
+	local file="${dir}/${filename}"
+
+	local -r now=$(date '+%Y-%m-%dT%T.%N%zZ')
+
+	# sanitise package list
+	PACKAGES=$(echo "$PACKAGES"|tr ' ' '\n'|sort -u|tr '\n' ' ')
+
+	local -r packages=$(for pkg in ${PACKAGES}; do echo "    - \"${pkg}\""; done)
+
+	mkdir -p "$dir"
+
+	# Semantic version of the summary file format.
+	#
+	# XXX: Increment every time the format of the summary file changes!
+	local -r format_version="0.0.1"
+
+	local -r osbuilder_url="https://github.com/kata-containers/osbuilder"
+
+	local agent="${AGENT_DEST}"
+	[ "$AGENT_INIT" = yes ] && agent="${init}"
+
+	local -r agent_version=$("$agent" --version|awk '{print $NF}')
+
+	cat >"$file"<<-EOT
+	---
+	osbuilder:
+	  url: "${osbuilder_url}"
+	  version: "${OSBUILDER_VERSION}"
+	rootfs-creation-time: "${now}"
+	description: "osbuilder rootfs"
+	file-format-version: "${format_version}"
+	architecture: "${ARCH}"
+	base-distro:
+	  name: "${OS_NAME}"
+	  version: "${OS_VERSION}"
+	  packages:
+${packages}
+	agent:
+	  url: "https://${GO_AGENT_PKG}"
+	  name: "${AGENT_BIN}"
+	  version: "${agent_version}"
+	  agent-is-init-daemon: "${AGENT_INIT}"
+EOT
+
+	local rootfs_file="${file_dir}/$(basename "${file}")"
+	info "Created summary file '${rootfs_file}' inside rootfs"
+}

tests/image_creation.bats

@@ -27,7 +27,12 @@ teardown(){
 
 function build_rootfs()
 {
+	local file="/var/lib/osbuilder/osbuilder.yaml"
+	local full="${tmp_rootfs}${file}"
+
 	sudo -E ${rootfs_sh} -r "${tmp_rootfs}" "${distro}"
+
+	yamllint "${full}"
 }
 
 function build_image()