[Buildroot] [v2] fs/aci: Add App Container Image (ACI) support to filesystems
Brian 'redbeard' Harrington
redbeard at coreos.com
Mon May 23 15:07:30 UTC 2016
App Container Images (ACI) are a Linux containerization image format
defined as a part of the AppC specification as defined by CoreOS,
Red Hat, Google, and community members. These images consist of a Linux
userland and a JSON metadata file describing how to execute the actual
runtime.
This filesystem package utilizes Buildroot for the generation of
the userland and provides the user with a mechanism for configuring the
contents of the manifest file.
---
Changes v1 -> v2
- Remove accidental 'default' of the fs/aci
- Remove dependency on host Jq
- Remove numerous "depends" lines in Kconfig, now in if block
- Set default name of localhost/buildroot as well as error check
- Allowed user to specify external manifest
- Enabled setting of timestamp annotation via a (non default) config
option
- Set default version via sha256 of .config file
- Added dependency on specific architectures
- Moved logic for architecture checks into Kconfig
- Use qstrip to clean up variables
- Export variables to scripts in package to avoid numerous
re-declarations
- Removed setting of xattrs in tar command
- Removed accidental re-use of TAR_OPTS
- Decoupled initial creation of tarball and adding of additional files
to simplify logic
- Removed stray debugging "echo" lines used during development
- Removed extra blank lines
- Moved logic for generation of json manifest into a shell script
Signed-off-by: Brian 'redbeard' Harrington <redbeard at coreos.com>
---
fs/Config.in | 1 +
fs/aci/Config.in | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/aci/aci.json.sh | 51 +++++++++++++++++++++++
fs/aci/aci.mk | 80 ++++++++++++++++++++++++++++++++++++
4 files changed, 249 insertions(+)
create mode 100644 fs/aci/Config.in
create mode 100755 fs/aci/aci.json.sh
create mode 100644 fs/aci/aci.mk
diff --git a/fs/Config.in b/fs/Config.in
index 51ccf28..1c468c5 100644
--- a/fs/Config.in
+++ b/fs/Config.in
@@ -1,5 +1,6 @@
menu "Filesystem images"
+source "fs/aci/Config.in"
source "fs/axfs/Config.in"
source "fs/cloop/Config.in"
source "fs/cpio/Config.in"
diff --git a/fs/aci/Config.in b/fs/aci/Config.in
new file mode 100644
index 0000000..4df4791
--- /dev/null
+++ b/fs/aci/Config.in
@@ -0,0 +1,117 @@
+config BR2_TARGET_ROOTFS_ACI
+ bool "app container image (aci)"
+ default n
+ depends on BR2_arm || BR2_armeb || BR2_aarch64_eb || BR2_i386 || BR2_x86_64 || BR2_powerpc64 || BR2_powerpc64le
+ depends on !BR2_ARM_CPU_ARMV4
+ help
+ Build an App Container Image for use with a Linux
+ containerization engine like rkt, Kurma, 3ofCoins, nosecone,
+ etc.
+
+if BR2_TARGET_ROOTFS_ACI
+
+config BR2_TARGET_ROOTFS_ACI_ARCH
+ string
+ default "i386" if BR2_i386
+ default "arm64" if BR2_x86_64
+ default "aarch64" if BR2_aarch64
+ default "aarch64_be" if BR2_aarch64_be
+ default "ppc64" if BR2_powerpc64
+ default "armv6l" if BR2_arm && BR2_ARM_CPU_ARMV6
+ default "armv7l" if BR2_arm && BR2_ARM_CPU_ARMV7A
+ default "armv7l" if BR2_arm && BR2_ARM_CPU_ARMV7M
+ default "armv7b" if BR2_armeb && BR2_ARM_CPU_ARMV7A
+ default "armv7b" if BR2_armeb && BR2_ARM_CPU_ARMV7M
+
+choice
+ prompt "compression method"
+ default BR2_TARGET_ROOTFS_ACI_NONE
+ help
+ Select compressor for application container image.
+
+config BR2_TARGET_ROOTFS_ACI_NONE
+ bool "no compression"
+ help
+ Do not compress the ACI.
+
+config BR2_TARGET_ROOTFS_ACI_GZIP
+ bool "gzip"
+ help
+ Do compress the ACI with gzip.
+
+config BR2_TARGET_ROOTFS_ACI_BZIP2
+ bool "bzip2"
+ help
+ Do compress the ACI with bzip2.
+
+config BR2_TARGET_ROOTFS_ACI_LZMA
+ bool "lzma"
+ help
+ Do compress the ACI with lzma.
+
+config BR2_TARGET_ROOTFS_ACI_LZO
+ bool "lzo"
+ help
+ Do compress the ACI with lzop.
+
+config BR2_TARGET_ROOTFS_ACI_XZ
+ bool "xz"
+ help
+ Do compress the ACI with xz.
+
+endchoice
+
+config BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+ bool "custom aci manifest"
+ help
+ Use custom aci manifest.
+
+if BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+config BR2_TARGET_ROOTFS_ACI_MANIFEST_PATH
+ string "custom path"
+ default ""
+ depends on BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+ help
+ Path to custom ACI manifest.
+endif # BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+
+if !BR2_TARGET_ROOTFS_ACI_OPTIONS_MANIFEST_CUSTOM
+config BR2_TARGET_ROOTFS_ACI_OPTIONS_NAME
+ string "name"
+ default "localhost/buildroot"
+ depends on !BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+ help
+ A human-readable name for this App Container Image (e.g.
+ example.com/my_app).
+
+comment "aci images must have a name"
+ depends on BR2_TARGET_ROOTFS_ACI_OPTIONS_NAME = "localhost/buildroot"
+ depends on !BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+
+config BR2_TARGET_ROOTFS_ACI_OPTIONS_EXEC
+ string "exec command"
+ depends on !BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+ help
+ Executable to launch on container instantiation and any relevant flags
+ (e.g. /bin/sh).
+
+config BR2_TARGET_ROOTFS_ACI_OPTIONS_VERSION
+ string "version"
+ depends on !BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+ help
+ When combined with "name", this SHOULD be unique for every
+ build of an app (on a given "os"/"arch" combination - e.g. v1.3.2).
+
+comment "aci images should be supplied with a version"
+ depends on BR2_TARGET_ROOTFS_ACI_OPTIONS_VERSION = ""
+ depends on !BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+
+config BR2_TARGET_ROOTFS_ACI_TIMESTAMP
+ bool "include created timestamp"
+ default n
+ depends on !BR2_TARGET_ROOTFS_ACI_USE_CUSTOM_MANIFEST
+ help
+ Include ACI annotation of timestamp when make was run.
+
+endif # !BR2_TARGET_ROOTFS_ACI_OPTIONS_MANIFEST_CUSTOM
+endif # BR2_TARGET_ROOTFS_ACI
diff --git a/fs/aci/aci.json.sh b/fs/aci/aci.json.sh
new file mode 100755
index 0000000..560e062
--- /dev/null
+++ b/fs/aci/aci.json.sh
@@ -0,0 +1,51 @@
+#!/bin/sh
+if [ "${ROOTFS_ACI_EXEC}n" == "n" ]; then
+ aciuser='"user": "0",'
+ acigroup='"group": "0"'
+else
+ aciuser='"user": '"\"${ROOTFS_ACI_EXEC}\","
+ acigroup='"group": '"\"${ROOTFS_ACI_EXEC}\""
+fi
+
+if [ "${ROOTFS_ACI_TIMESTAMP}n" != "n" ]; then
+createdat=",
+ {
+ \"name\": \"created\",
+ \"value\": \"${ROOTFS_ACI_TIMESTAMP}\"
+ }"
+fi
+
+
+cat <<EOF
+{
+ "acKind":"ImageManifest",
+ "acVersion":"0.7.4",
+ "name": "${ROOTFS_ACI_NAME}",
+ "labels":
+ [{
+ "name":"os",
+ "value":"linux"
+ },{
+ "name":"arch",
+ "value": "${ROOTFS_ACI_ARCH}"
+ },{
+ "name":"version",
+ "value": "${ROOTFS_ACI_VERSION}"
+ }],
+ "app":
+ {
+ "exec":
+ [
+ "${ROOTFS_ACI_EXEC}"
+ ],
+ ${aciuser}
+ ${acigroup}
+ },
+ "annotations":
+ [{
+ "name": "buildroot.org/aci",
+ "value": "Generated by Buildroot"
+ }${createdat}
+ ]
+}
+EOF
diff --git a/fs/aci/aci.mk b/fs/aci/aci.mk
new file mode 100644
index 0000000..abec378
--- /dev/null
+++ b/fs/aci/aci.mk
@@ -0,0 +1,80 @@
+################################################################################
+#
+# Generate App Container Image (ACI)
+# https://github.com/appc/spec/blob/master/spec/aci.md
+#
+################################################################################
+
+ROOTFS_ACI_NAME = $(call qstrip,$(BR2_TARGET_ROOTFS_ACI_OPTIONS_NAME))
+ROOTFS_ACI_EXEC = $(call qstrip,$(BR2_TARGET_ROOTFS_ACI_OPTIONS_EXEC))
+ROOTFS_ACI_ARCH = $(call qstrip,$(BR2_TARGET_ROOTFS_ACI_ARCH))
+ROOTFS_ACI_VERSION = $(call qstrip,$(BR2_TARGET_ROOTFS_ACI_OPTIONS_VERSION))
+ROOTFS_ACI_MANIFEST = $(call qstrip,$(BR2_TARGET_ROOTFS_ACI_MANIFEST_PATH))
+
+# Passing the generated variables into the running environment for make targets
+# leads to a cleaner implementation of the resulting shell scripts. In this way
+# nothing getting passed to tar should need quotes
+export ROOTFS_ACI_NAME
+export ROOTFS_ACI_EXEC
+export ROOTFS_ACI_ARCH
+export ROOTFS_ACI_VERSION
+export ROOTFS_ACI_MANIFEST
+
+# If the user does not supply a version number, generate one which should play
+# nicely with reproducible builds, ideally signalling that for a given pairing
+# of buildroot version and config generates a consistent output.
+ifndef $(ROOTFS_ACI_VERSION)
+ROOTFS_ACI_VERSION = $(shell cat .config | sha256sum | cut -f1 -d' ')
+endif
+
+# In continuing support of deterministic builds, allow the user to annotate a
+# manifest with a timestamp but do not make this the default behavior. In this
+# case it will be the timestamp of when "make" is run.
+ifeq ($(BR2_TARGET_ROOTFS_ACI_TIMESTAMP),y)
+ROOTFS_ACI_TIMESTAMP = $(shell date --rfc-3339=ns | tr " " "T")
+export ROOTFS_ACI_TIMESTAMP
+endif
+
+# For the generation of our ACI we pass the variables from the main
+# configuration into a scrip to generate a JSON manifest unless the user
+# provided their own manifest
+ifneq ($(ROOTFS_ACI_MANIFEST),)
+define ROOTFS_ACI_COPY_MANIFEST
+ cp '$(ROOTFS_ACI_MANIFEST)' $(BINARIES_DIR)/manifest
+endef
+ROOTFS_ACI_PRE_GEN_HOOKS += ROOTFS_ACI_COPY_MANIFEST
+else
+define ROOTFS_ACI_GENERATE_MANIFEST
+ fs/aci/aci.json.sh > $(BINARIES_DIR)/manifest
+endef
+ROOTFS_ACI_PRE_GEN_HOOKS += ROOTFS_ACI_GENERATE_MANIFEST
+endif
+
+# We then create the TAR archive of all components, making sure all paths are
+# represented correctly. Unfortunately as per fs/common.mk:8 the only a single
+# command is allowed. The spec requires storing any relevant xattrs but as of
+# 2016-05-22 buildroot does not generate these, though tooling inside the
+# target system can be added via the package BR2_PACKAGE_ATTR
+define ROOTFS_ACI_CMD
+ tar -cf $@ -C $(BINARIES_DIR) --owner=0 --group=0 manifest && \
+ tar -rf $@ -C $(TARGET_DIR) --numeric-owner --transform 's,^\./,rootfs/,' .
+endef
+
+# ACI images are required to end in ".aci" regardless of compression
+ifneq ($(BR2_TARGET_ROOTFS_ACI_NONE),y)
+define ROOTFS_ACI_MOVE
+ mv -f $(BINARIES_DIR)/rootfs.aci$(ROOTFS_ACI_COMPRESS_EXT) \
+ $(BINARIES_DIR)/rootfs.aci
+endef
+
+ROOTFS_ACI_POST_GEN_HOOKS += ROOTFS_ACI_MOVE
+endif
+
+ifeq ($(ROOTFS_ACI_NAME),)
+ifeq ($(call qstrip,$(ROOTFS_ACI_MANIFEST)),)
+$(error You supplied neither BR2_TARGET_ROOTFS_ACI_MANIFEST_PATH, \
+ROOTFS_ACI_NAME, nor BR2_TARGET_ROOTFS_ACI_OPTIONS_NAME)
+endif
+endif
+
+$(eval $(call ROOTFS_TARGET,aci))
--
2.4.11
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