From: Justin Cinkelj <justin.cink...@xlab.si>
Committer: Nadav Har'El <n...@scylladb.com>
Branch: master
cloud-init: support standard ISO images
In 56c6195b252b127c7fe90cb9fa46c370b384b51a was added option for
reading configuration file from a secondary disk. This is so-called
NoCloud configuration method, see also
http://cloudinit.readthedocs.io/en/0.7.9/topics/datasources/nocloud.html.
Due to missing ISO filesystem support, a custom disk format was used.
This patch replaces custom disk format with standard ISO images.
ISO FS support is provided by libcdio.
After preparing user-data file (meta-data file is currently ignored),
the image can be build with cloud-localds program (provided by cloud-utils
package on fedora).
Signed-off-by: Justin Cinkelj <justin.cink...@xlab.si>
Message-Id: <20170712213724.4347-1-justin.cink...@xlab.si>
---
diff --git a/modules/cloud-init/Makefile b/modules/cloud-init/Makefile
--- a/modules/cloud-init/Makefile
+++ b/modules/cloud-init/Makefile
@@ -1,4 +1,5 @@
-INCLUDES += -I../../include -I.
+INCLUDES = -I. -I../../include -I../../arch/$(ARCH) -I../.. \
+ -I../../build/$(mode)/gen/include
autodepend = -MD -MT $@ -MP
CXXFLAGS = -g -rdynamic -Wall -std=c++11 -fPIC $(INCLUDES) $(autodepend)
diff --git a/modules/cloud-init/main.cc b/modules/cloud-init/main.cc
--- a/modules/cloud-init/main.cc
+++ b/modules/cloud-init/main.cc
@@ -5,6 +5,9 @@
* BSD license as described in the LICENSE file in the top-level directory.
*/
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
#include "cloud-init.hh"
#include "files-module.hh"
#include "server-module.hh"
@@ -15,59 +18,60 @@
#include <boost/program_options/parsers.hpp>
#include <osv/debug.hh>
#include <osv/exception_utils.hh>
+#include <osv/run.hh>
using namespace std;
using namespace init;
namespace po = boost::program_options;
-// config_disk() checks whether we have a second disk (/dev/vblk1) which
-// holds nothing but a configuration file, and if there is, it copies the
-// configuration to the given file.
-// Currently, the configuration disk must be in a trivial format generated
-// by scripts/file2img: A magic header, then the length of the file (in
-// decimal), followed by the content.
+// config_disk() allows to use NoCloud VM configuration method - see
+//
http://cloudinit.readthedocs.io/en/0.7.9/topics/datasources/nocloud.html.
+// NoCloud method provides two files with cnfiguration data (/user-data and
+// /meta-data) on a disk. The disk is required to have label "cidata".
+// It can contain ISO9660 or FAT filesystem.
+//
+// config_disk() checks whether we have a second disk (/dev/vblk1) with
+// ISO image, and if there is, it copies the configuration file from
+// /user-data to the given file.
// config_disk() returns true if it has successfully read the configuration
// into the requested file.
+//
+// OSv implementation limitations:
+// The /meta-data file is currently ignored.
+// Only ISO9660 filesystem is supported.
+// The mandatory "cidata" volume label is not checked.
+//
+// Example ISO image can be created by running
+// cloud-localds cloud-init.img cloud-init.yaml
+// The cloud-localds command is provided by cloud-utils package (fedora).
static bool config_disk(const char* outfile) {
- int fd = open("/dev/vblk1", O_RDONLY);
- if (fd < 0) {
+ char disk[] = "/dev/vblk1";
+ char srcfile[] = "/user-data";
+ struct stat sb;
+ int ret;
+ int app_ret = -1;
+
+ ret = stat(disk, &sb);
+ if (ret != 0) {
return false;
}
- char data[512];
- ssize_t r = read(fd, data, sizeof(data));
- static const char* magic = "!file_in_image\n";
- ssize_t magic_len = strlen(magic);
- if (r < magic_len || strncmp(data, magic, magic_len)) {
- close(fd);
+
+ std::vector<std::string> cmd = {"/usr/bin/iso-read.so", "-e",
srcfile, "-o", outfile, disk};
+ osv::run(cmd[0], cmd, &app_ret);
+ if (app_ret != 0) {
+ debug("cloud-init: warning, %s exited with code %d (%s is not ISO
image?)\n", cmd[0], app_ret, disk);
return false;
}
- debug("cloud-init: found configuration in /dev/vblk1\n");
- int out = open(outfile, O_WRONLY|O_CREAT, 0777);
- if (out < 0) {
- debug("cloud-init: failed to copy configuration to %s\n", outfile);
- close(fd);
+ ret = stat(outfile, &sb);
+ if (ret != 0) {
+ debug("cloud-init: stat(%s) failed, errno=%d\n", outfile, errno);
return false;
}
- unsigned offset = magic_len;
- while (offset < r && data[offset] != '\n')
- offset++;
- offset++; // skip the \n too
- ssize_t filelen = atoi(data + magic_len);
- while (filelen) {
- int len = std::min(filelen, r - offset);
- if (len <= 0) {
- debug("cloud-init: unexpected end of image\n", outfile);
- close(fd);
- close(out);
- return false;
- }
- write(out, data + offset, len);
- filelen -= len;
- offset = 0;
- r = read(fd, data, sizeof(data));
+ if ((sb.st_mode & S_IFMT) != S_IFREG) {
+ debug("cloud-init: %s is not a file\n", outfile);
+ return false;
}
- close(fd);
- close(out);
+ debug("cloud-init: copied file %s -> %s from ISO image %s\n", srcfile,
outfile, disk);
return true;
}
diff --git a/modules/cloud-init/module.py b/modules/cloud-init/module.py
--- a/modules/cloud-init/module.py
+++ b/modules/cloud-init/module.py
@@ -12,6 +12,7 @@
api.require('httpserver')
api.require('libyaml')
+api.require('libcdio')
#default = api.run('/usr/mgmt/cloud-init.so --skip-error --file
/usr/mgmt/cloud-init.yaml')
default = ""
diff --git a/scripts/file2img b/scripts/file2img
--- a/scripts/file2img
+++ b/scripts/file2img
@@ -1,15 +0,0 @@
-#!/bin/sh
-#
-# This scripts create a trivial disk image file which contains a single
-# file $1. If this image is mounted as a disk, the guest can read the
-# content of this file in a fairly trivial manner.
-#
-# For simplicity, the image we create does not have any partitions, and
-# certainly not a file system. It just has the following content:
-# !file_in_image\n # a magic header
-# 1234\n # the size of the following file (ascii
number)
-# the content of the file...
-
-echo "!file_in_image"
-stat -c %s "$1"
-cat "$1"
--
You received this message because you are subscribed to the Google Groups "OSv
Development" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to osv-dev+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
