Add /etc/libguestfs-tools.conf configuration file.

This allows the default for --ro or --rw to be controlled for the
three tools guestfish, guestmount and virt-rescue.

README

@@ -32,6 +32,8 @@ Requirements
 
 - libxml2 (optional)
 
+- libconfig (optional, to parse /etc/libguestfs-tools.conf)
+
 - Augeas (http://augeas.net/) (optional)
 
 - gperf

cat/Makefile.am

@@ -1,5 +1,5 @@
 # libguestfs virt-cat, virt-filesystems and virt-ls.
-# Copyright (C) 2010 Red Hat Inc.
+# Copyright (C) 2010-2011 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -33,6 +33,7 @@ CLEANFILES = stamp-virt-cat.pod stamp-virt-ls.pod stamp-virt-filesystems.pod
 bin_PROGRAMS = virt-cat virt-filesystems virt-ls
 
 SHARED_SOURCE_FILES = \
+	../fish/config.c \
 	../fish/inspect.c \
 	../fish/keys.c \
 	../fish/options.h \
@@ -48,9 +49,11 @@ virt_cat_CFLAGS = \
 	-I$(top_srcdir)/fish \
 	-I$(srcdir)/../gnulib/lib -I../gnulib/lib \
 	-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
-	$(WARN_CFLAGS) $(WERROR_CFLAGS)
+	$(WARN_CFLAGS) $(WERROR_CFLAGS) \
+	$(LIBCONFIG_CFLAGS)
 
 virt_cat_LDADD = \
+	$(LIBCONFIG_LIBS) \
 	$(top_builddir)/src/libguestfs.la \
 	../gnulib/lib/libgnu.la
 
@@ -63,9 +66,11 @@ virt_filesystems_CFLAGS = \
 	-I$(top_srcdir)/fish \
 	-I$(srcdir)/../gnulib/lib -I../gnulib/lib \
 	-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
-	$(WARN_CFLAGS) $(WERROR_CFLAGS)
+	$(WARN_CFLAGS) $(WERROR_CFLAGS) \
+	$(LIBCONFIG_CFLAGS)
 
 virt_filesystems_LDADD = \
+	$(LIBCONFIG_LIBS) \
 	$(top_builddir)/src/libguestfs.la \
 	../gnulib/lib/libgnu.la
 
@@ -78,9 +83,11 @@ virt_ls_CFLAGS = \
 	-I$(top_srcdir)/fish \
 	-I$(srcdir)/../gnulib/lib -I../gnulib/lib \
 	-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
-	$(WARN_CFLAGS) $(WERROR_CFLAGS)
+	$(WARN_CFLAGS) $(WERROR_CFLAGS) \
+	$(LIBCONFIG_CFLAGS)
 
 virt_ls_LDADD = \
+	$(LIBCONFIG_LIBS) \
 	$(top_builddir)/src/libguestfs.la \
 	../gnulib/lib/libgnu.la
 

configure.ac

@@ -431,6 +431,15 @@ PKG_CHECK_MODULES([LIBXML2], [libxml-2.0],
         [AC_MSG_WARN([libxml2 not found, some core features will be disabled])])
 AM_CONDITIONAL([HAVE_LIBXML2],[test "x$LIBXML2_LIBS" != "x"])
 
+dnl libconfig (highly recommended)
+PKG_CHECK_MODULES([LIBCONFIG], [libconfig],
+        [AC_SUBST([LIBCONFIG_CFLAGS])
+         AC_SUBST([LIBCONFIG_LIBS])
+         AC_DEFINE([HAVE_LIBCONFIG],[1],[libconfig found at compile time.])
+        ],
+        [AC_MSG_WARN([libconfig not found, some features will be disabled])])
+AM_CONDITIONAL([HAVE_LIBCONFIG],[test "x$LIBCONFIG_LIBS" != "x"])
+
 dnl hivex library (highly recommended)
 dnl This used to be a part of libguestfs, but was spun off into its
 dnl own separate upstream project in libguestfs 1.0.85.

df/Makefile.am

@@ -1,5 +1,5 @@
 # libguestfs virt-df
-# Copyright (C) 2010 Red Hat Inc.
+# Copyright (C) 2010-2011 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -28,6 +28,7 @@ CLEANFILES = stamp-virt-df.pod
 bin_PROGRAMS = virt-df
 
 SHARED_SOURCE_FILES = \
+	../fish/config.c \
 	../fish/inspect.c \
 	../fish/keys.c \
 	../fish/options.h \
@@ -48,9 +49,11 @@ virt_df_CFLAGS = \
 	-I$(srcdir)/../gnulib/lib -I../gnulib/lib \
 	-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
 	$(WARN_CFLAGS) $(WERROR_CFLAGS) \
+	$(LIBCONFIG_CFLAGS) \
 	$(LIBVIRT_CFLAGS)
 
 virt_df_LDADD = \
+	$(LIBCONFIG_LIBS) \
 	$(top_builddir)/src/libguestfs.la \
 	../gnulib/lib/libgnu.la \
 	$(LIBVIRT_LIBS) \

fish/Makefile.am

@@ -1,5 +1,5 @@
 # libguestfs
-# Copyright (C) 2009-2010 Red Hat Inc.
+# Copyright (C) 2009-2011 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -60,6 +60,7 @@ EXTRA_DIST = \
 # so we know which ones are shared.  These files must not include
 # other guestfish files.
 SHARED_SOURCE_FILES = \
+	config.c \
 	inspect.c \
 	keys.c \
 	options.h \
@@ -118,10 +119,13 @@ guestfish_CFLAGS = \
 	-DGUESTFS_DEFAULT_PATH='"$(libdir)/guestfs"' \
 	-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
 	-I$(srcdir)/../gnulib/lib -I../gnulib/lib \
-	$(WARN_CFLAGS) $(WERROR_CFLAGS)
+	$(WARN_CFLAGS) $(WERROR_CFLAGS) \
+	$(LIBCONFIG_CFLAGS)
 
 guestfish_LDADD = \
-	$(top_builddir)/src/libguestfs.la $(LIBREADLINE) -lm
+	$(LIBCONFIG_LIBS) \
+	$(LIBREADLINE) \
+	$(top_builddir)/src/libguestfs.la -lm
 
 # Make guestfish use the convenience libraries.
 noinst_LTLIBRARIES = libcmds.la librc_protocol.la
@@ -207,6 +211,11 @@ stamp-virt-tar-out.pod: virt-tar-out.pod
 	  $<
 	touch $@
 
+# libguestfs tools config file.
+
+toolsconfdir = $(sysconfdir)
+toolsconf_DATA = libguestfs-tools.conf
+
 # Bash completion script.
 
 bashcompletiondir = $(sysconfdir)/bash_completion.d

fish/config.c

@@ -0,0 +1,142 @@
+/* libguestfs - guestfish and guestmount shared option parsing
+ * Copyright (C) 2011 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef HAVE_LIBCONFIG
+#include <libconfig.h>
+#endif
+
+#include "guestfs.h"
+
+#include "options.h"
+
+static const char *home_filename = /* $HOME/ */ ".libguestfs-tools.rc";
+static const char *etc_filename = "/etc/libguestfs-tools.conf";
+
+#ifdef HAVE_LIBCONFIG
+
+/* Note that parse_config is called very early, before command line
+ * parsing and before the verbose flag has been set.
+ */
+
+void
+parse_config (void)
+{
+  const char *home;
+  size_t len;
+  char *path;
+  FILE *fp;
+  config_t conf;
+
+  config_init (&conf);
+
+  /* Try $HOME first. */
+  home = getenv ("HOME");
+  if (home != NULL) {
+    len = strlen (home) + 1 + strlen (home_filename) + 1;
+    path = malloc (len);
+    if (path == NULL) {
+      perror ("malloc");
+      exit (EXIT_FAILURE);
+    }
+    snprintf (path, len, "%s/%s", home, home_filename);
+
+    fp = fopen (path, "r");
+    if (fp != NULL) {
+      /*
+      if (verbose)
+        fprintf (stderr, "%s: reading configuration from %s\n",
+                 program_name, path);
+      */
+
+      if (config_read (&conf, fp) == CONFIG_FALSE) {
+        fprintf (stderr,
+                 _("%s: %s: line %d: error parsing configuration file: %s\n"),
+                 program_name, path, config_error_line (&conf),
+                 config_error_text (&conf));
+        exit (EXIT_FAILURE);
+      }
+
+      if (fclose (fp) == -1) {
+        perror (path);
+        exit (EXIT_FAILURE);
+      }
+
+      /* Notes:
+       *
+       * (1) It's not obvious from the documentation, that config_read
+       * completely resets the 'conf' structure.  This means we cannot
+       * call config_read twice on the two possible configuration
+       * files, but instead have to copy out settings into our
+       * variables between calls.
+       *
+       * (2) If the next call fails then 'read_only' variable is not
+       * updated.  Failure could happen just because the setting is
+       * missing from the configuration file, so we ignore it here.
+       */
+      config_lookup_bool (&conf, "read_only", &read_only);
+    }
+
+    free (path);
+  }
+
+  fp = fopen (etc_filename, "r");
+  if (fp != NULL) {
+    /*
+    if (verbose)
+      fprintf (stderr, "%s: reading configuration from %s\n",
+               program_name, etc_filename);
+    */
+
+    if (config_read (&conf, fp) == CONFIG_FALSE) {
+      fprintf (stderr,
+               _("%s: %s: line %d: error parsing configuration file: %s\n"),
+               program_name, etc_filename, config_error_line (&conf),
+               config_error_text (&conf));
+      exit (EXIT_FAILURE);
+    }
+
+    if (fclose (fp) == -1) {
+      perror (path);
+      exit (EXIT_FAILURE);
+    }
+
+    config_lookup_bool (&conf, "read_only", &read_only);
+  }
+
+  config_destroy (&conf);
+}
+
+#else /* !HAVE_LIBCONFIG */
+
+void
+parse_config (void)
+{
+  /*
+  if (verbose)
+    fprintf (stderr,
+             _("%s: compiled without libconfig, guestfish configuration file ignored\n"),
+             program_name);
+  */
+}
+
+#endif /* !HAVE_LIBCONFIG */

fish/fish.c

@@ -158,6 +158,8 @@ main (int argc, char *argv[])
   bindtextdomain (PACKAGE, LOCALEBASEDIR);
   textdomain (PACKAGE);
 
+  parse_config ();
+
   set_up_terminal ();
 
   enum { HELP_OPTION = CHAR_MAX + 1 };

fish/guestfish.pod

@@ -402,7 +402,9 @@ Display the guestfish / libguestfs version number and exit.
 
 =item B<--rw>
 
-This option does nothing at the moment.
+This changes the I<-a>, I<-d> and I<-m> options so that disks are
+added and mounts are done read-write.
+
 See L</OPENING DISKS FOR READ AND WRITE> below.
 
 =item B<-x>
@@ -466,27 +468,30 @@ asked for without doing this.
 
 =head1 OPENING DISKS FOR READ AND WRITE
 
-The guestfish (and L<guestmount(1)>) options I<--ro> and I<--rw>
-affect whether the other command line options I<-a>, I<-c>, I<-d>,
-I<-i> and I<-m> open disk images read-only or for writing.
+The guestfish, L<guestmount(1)> and L<virt-rescue(1)> options I<--ro>
+and I<--rw> affect whether the other command line options I<-a>,
+I<-c>, I<-d>, I<-i> and I<-m> open disk images read-only or for
+writing.
 
-In libguestfs E<lt> 1.6.2, guestfish and guestmount defaulted to
-opening disk images supplied on the command line for write.  To open a
-disk image read-only you have to do I<-a image --ro>.
+In libguestfs E<le> 1.8, guestfish, guestmount and virt-rescue
+defaulted to opening disk images supplied on the command line for
+write.  To open a disk image read-only you have to do I<-a image --ro>.
 
 This matters: If you accidentally open a live VM disk image writable
 then you will cause irreversible disk corruption.
 
-By libguestfs 1.10 we intend to change the default the other way.  Disk
-images will be opened read-only.  You will have to either specify
-I<guestfish --rw> or change a configuration file in order to get write
-access for disk images specified by those other command line options.
+By libguestfs 1.10 we intend to change the default the other way.
+Disk images will be opened read-only.  You will have to either specify
+I<guestfish --rw>, I<guestmount --rw>, I<virt-rescue --rw>, or change
+the configuration file C</etc/libguestfs-tools.conf> in order to get
+write access for disk images specified by those other command line
+options.
 
-This version of guestfish has a I<--rw> option which does nothing (it
-is already the default).  However it is highly recommended that you
-use this option to indicate that guestfish needs write access, and to
-prepare your scripts for the day when this option will be required for
-write access.
+This version of guestfish, guestmount and virt-rescue has a I<--rw>
+option which does nothing (it is already the default).  However it is
+highly recommended that you use this option to indicate that you need
+write access, and prepare your scripts for the day when this option
+will be required for write access.
 
 B<Note:> This does I<not> affect commands like L</add> and L</mount>,
 or any other libguestfs program apart from guestfish and guestmount.
@@ -1081,6 +1086,15 @@ enough.
 
 =over 4
 
+=item $HOME/.libguestfs-tools.rc
+
+=item /etc/libguestfs-tools.conf
+
+This configuration file controls the default read-only or read-write
+mode (I<--ro> or I<--rw>).
+
+See L</OPENING DISKS FOR READ AND WRITE>.
+
 =item $HOME/.guestfish
 
 If compiled with GNU readline support, then the command history
@@ -1156,7 +1170,7 @@ Richard W.M. Jones (C<rjones at redhat dot com>)
 
 =head1 COPYRIGHT
 
-Copyright (C) 2009-2010 Red Hat Inc.
+Copyright (C) 2009-2011 Red Hat Inc.
 L<http://libguestfs.org/>
 
 This program is free software; you can redistribute it and/or modify

fish/libguestfs-tools.conf

@@ -0,0 +1,24 @@
+# /etc/libguestfs-tools.conf or .libguestfs-tools.rc
+#
+# This configuration file changes the defaults for the following programs:
+#   * guestfish
+#   * guestmount
+#   * virt-rescue
+# For more information on these programs, read the manual pages
+# (guestfish(1) etc).
+#
+# /etc/libguestfs-tools.conf is the global configuration file for all
+# of the above programs.  Local users can override the global
+# configuration by copying this file into '.libguestfs-tools.rc' in
+# their home directory and modifying it accordingly.
+#
+# This file is parsed by the libconfig library.  For more information
+# about the format, see
+# http://www.hyperrealm.com/libconfig/libconfig_manual.html
+
+# Uncomment the following line to make guestfish, guestmount,
+# virt-rescue be read-only by default (as if the --ro flag was given).
+# If it is commented out then the default is read-write.  Note that
+# the semi-colon (;) is required.
+
+#read_only = true;

fish/options.h

@@ -112,6 +112,9 @@ struct mp {
   char *options;
 };
 
+/* in config.c */
+extern void parse_config (void);
+
 /* in inspect.c */
 extern void inspect_mount (void);
 extern void print_inspect_prompt (void);

fuse/Makefile.am

@@ -28,6 +28,7 @@ bin_PROGRAMS = guestmount
 # These source files (all related to option parsing) are shared
 # between guestfish and guestmount.
 SHARED_SOURCE_FILES = \
+	../fish/config.c \
 	../fish/inspect.c \
 	../fish/keys.c \
 	../fish/options.h \
@@ -48,10 +49,12 @@ guestmount_CFLAGS = \
 	-DGUESTFS_DEFAULT_PATH='"$(libdir)/guestfs"' \
 	-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
 	$(FUSE_CFLAGS) \
+	$(LIBCONFIG_CFLAGS) \
 	$(WARN_CFLAGS) $(WERROR_CFLAGS)
 
 guestmount_LDADD = \
 	$(FUSE_LIBS) -lulockmgr \
+	$(LIBCONFIG_LIBS) \
 	$(top_builddir)/src/libguestfs.la \
 	../gnulib/lib/libgnu.la
 

fuse/guestmount.c

@@ -947,6 +947,8 @@ main (int argc, char *argv[])
   bindtextdomain (PACKAGE, LOCALEBASEDIR);
   textdomain (PACKAGE);
 
+  parse_config ();
+
   enum { HELP_OPTION = CHAR_MAX + 1 };
 
   /* The command line arguments are broadly compatible with (a subset

fuse/guestmount.pod

@@ -236,7 +236,9 @@ Display the program version and exit.
 
 =item B<-w> | B<--rw>
 
-This option does nothing at the moment.
+This changes the I<-a>, I<-d> and I<-m> options so that disks are
+added and mounts are done read-write.
+
 See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
 
 =item B<-x> | B<--trace>
@@ -247,6 +249,21 @@ This also stops the daemon from forking into the background.
 
 =back
 
+=head1 FILES
+
+=over 4
+
+=item $HOME/.libguestfs-tools.rc
+
+=item /etc/libguestfs-tools.conf
+
+This configuration file controls the default read-only or read-write
+mode (I<--ro> or I<--rw>).
+
+See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
+
+=back
+
 =head1 SEE ALSO
 
 L<guestfish(1)>,

inspector/Makefile.am

@@ -1,5 +1,5 @@
 # libguestfs virt-inspector
-# Copyright (C) 2009-2010 Red Hat Inc.
+# Copyright (C) 2009-2011 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -48,6 +48,7 @@ if HAVE_LIBXML2
 bin_PROGRAMS = virt-inspector
 
 SHARED_SOURCE_FILES = \
+	../fish/config.c \
 	../fish/inspect.c \
 	../fish/keys.c \
 	../fish/options.h \
@@ -64,9 +65,11 @@ virt_inspector_CFLAGS = \
 	-I$(srcdir)/../gnulib/lib -I../gnulib/lib \
 	-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
 	$(LIBXML2_CFLAGS) \
+	$(LIBCONFIG_CFLAGS) \
 	$(WARN_CFLAGS) $(WERROR_CFLAGS)
 
 virt_inspector_LDADD = \
+	$(LIBCONFIG_LIBS) \
 	$(top_builddir)/src/libguestfs.la \
 	$(LIBXML2_LIBS) \
 	../gnulib/lib/libgnu.la

po/POTFILES.in

@@ -82,6 +82,7 @@ fish/alloc.c
 fish/cmds.c
 fish/cmds_gperf.c
 fish/completion.c
+fish/config.c
 fish/copy.c
 fish/destpaths.c
 fish/echo.c

rescue/Makefile.am

@@ -1,5 +1,5 @@
 # libguestfs virt-rescue
-# Copyright (C) 2010 Red Hat Inc.
+# Copyright (C) 2010-2011 Red Hat Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -26,6 +26,7 @@ CLEANFILES = stamp-virt-rescue.pod
 bin_PROGRAMS = virt-rescue
 
 SHARED_SOURCE_FILES = \
+	../fish/config.c \
 	../fish/inspect.c \
 	../fish/keys.c \
 	../fish/options.h \
@@ -41,9 +42,11 @@ virt_rescue_CFLAGS = \
 	-I$(top_srcdir)/fish \
 	-I$(srcdir)/../gnulib/lib -I../gnulib/lib \
 	-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
+	$(LIBCONFIG_CFLAGS) \
 	$(WARN_CFLAGS) $(WERROR_CFLAGS)
 
 virt_rescue_LDADD = \
+	$(LIBCONFIG_LIBS) \
 	$(top_builddir)/src/libguestfs.la \
 	../gnulib/lib/libgnu.la
 

rescue/virt-rescue.c

@@ -95,6 +95,8 @@ main (int argc, char *argv[])
   bindtextdomain (PACKAGE, LOCALEBASEDIR);
   textdomain (PACKAGE);
 
+  parse_config ();
+
   enum { HELP_OPTION = CHAR_MAX + 1 };
 
   static const char *options = "a:c:d:m:rvVx";

rescue/virt-rescue.pod

@@ -167,6 +167,8 @@ The option must always be used if the disk image or virtual machine
 might be running, and is generally recommended in cases where you
 don't need write access to the disk.
 
+See also L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
+
 =item B<--selinux>
 
 Enable SELinux in the rescue appliance.  You should read
@@ -188,7 +190,9 @@ Display version number and exit.
 
 =item B<--rw>
 
-This option does nothing at the moment.
+This changes the I<-a> and I<-d> options so that disks are
+added and mounts are done read-write.
+
 See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
 
 =item B<-x>
@@ -261,6 +265,21 @@ have meaning to the shell such as C<#> and space.  You may need to
 quote or escape these characters on the command line.  See the shell
 manual page L<sh(1)> for details.
 
+=head1 FILES
+
+=over 4
+
+=item $HOME/.libguestfs-tools.rc
+
+=item /etc/libguestfs-tools.conf
+
+This configuration file controls the default read-only or read-write
+mode (I<--ro> or I<--rw>).
+
+See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
+
+=back
+
 =head1 SEE ALSO
 
 L<guestfs(3)>,
@@ -275,7 +294,7 @@ Richard W.M. Jones L<http://people.redhat.com/~rjones/>
 
 =head1 COPYRIGHT
 
-Copyright (C) 2009-2010 Red Hat Inc.
+Copyright (C) 2009-2011 Red Hat Inc.
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by