ostree admin instutil set-kargs: make more flexible

Add command line arguments:
 --import-proc-cmdline: import values from /proc/cmdline
 --merge: import current values
 --replace=ARG=VALUE: replace value
 --append=ARG=VALUE: append a new argument

Extra command line arguments are treated like --append=, which
gives backwards compatibility.

https://bugzilla.gnome.org/show_bug.cgi?id=731051

doc/ostree-admin-instutil.xml

@@ -75,10 +75,13 @@ Boston, MA 02111-1307, USA.
             </varlistentry>
 
             <varlistentry>
-                <term><command>set-kargs</command></term>
+                <term><command>set-kargs <arg choice="opt">--merge</arg> <arg choice="opt">--import-proc-cmdline</arg> <arg choice="opt">--append=ARG</arg> <arg choice="opt">--replace=ARG</arg> <arg choice="opt">MORE_APPEND_ARGS</arg></command></term>
 
                 <listitem><para>
-                    Replace the kernel arguments of the default deployment.
+                    Replace the kernel arguments of the default deployment. The new arguments are based
+                    on an empty list (the default), the current options (--merge), or the arguments
+                    of the loaded kernel (--import-proc-cmdline), and new options either are added to the
+                    end (--append=ARG) or replace existing arguments of the same name (--replace=ARG).
                 </para></listitem>
             </varlistentry>
         </variablelist>

src/libostree/ostree-kernel-args.c

@@ -21,6 +21,7 @@
 #include "config.h"
 
 #include "ostree-kernel-args.h"
+#include "libgsystem.h"
 
 #include <string.h>
 
@@ -156,6 +157,29 @@ _ostree_kernel_args_append_argv (OstreeKernelArgs  *kargs,
     }
 }
 
+gboolean
+_ostree_kernel_args_append_proc_cmdline (OstreeKernelArgs *kargs,
+                                         GCancellable     *cancellable,
+                                         GError          **error)
+{
+  gs_unref_object GFile *proc_cmdline_path = g_file_new_for_path ("/proc/cmdline");
+  gs_free char *proc_cmdline = NULL;
+  gsize proc_cmdline_len = 0;
+  gs_strfreev char **proc_cmdline_args = NULL;
+
+  if (!g_file_load_contents (proc_cmdline_path, cancellable,
+                             &proc_cmdline, &proc_cmdline_len,
+                             NULL, error))
+    return FALSE;
+
+  g_strchomp (proc_cmdline);
+
+  proc_cmdline_args = g_strsplit (proc_cmdline, " ", -1);
+  _ostree_kernel_args_append_argv (kargs, proc_cmdline_args);
+
+  return TRUE;
+}
+
 void
 _ostree_kernel_args_parse_append (OstreeKernelArgs *kargs,
                                   const char       *options)

src/libostree/ostree-kernel-args.h

@@ -40,6 +40,10 @@ void _ostree_kernel_args_append (OstreeKernelArgs  *kargs,
 void _ostree_kernel_args_append_argv (OstreeKernelArgs  *kargs,
                                       char **argv);
 
+gboolean _ostree_kernel_args_append_proc_cmdline (OstreeKernelArgs *kargs,
+                                                  GCancellable     *cancellable,
+                                                  GError          **error);
+
 void _ostree_kernel_args_parse_append (OstreeKernelArgs *kargs,
                                        const char *options);
 

src/ostree/ot-admin-builtin-deploy.c

@@ -130,20 +130,8 @@ ot_admin_builtin_deploy (int argc, char **argv, OstreeSysroot *sysroot, GCancell
    */
   if (opt_kernel_proc_cmdline)
     {
-      gs_unref_object GFile *proc_cmdline_path = g_file_new_for_path ("/proc/cmdline");
-      gs_free char *proc_cmdline = NULL;
-      gsize proc_cmdline_len = 0;
-      gs_strfreev char **proc_cmdline_args = NULL;
-
-      if (!g_file_load_contents (proc_cmdline_path, cancellable,
-                                 &proc_cmdline, &proc_cmdline_len,
-                                 NULL, error))
+      if (!_ostree_kernel_args_append_proc_cmdline (kargs, cancellable, error))
         goto out;
-
-      g_strchomp (proc_cmdline);
-
-      proc_cmdline_args = g_strsplit (proc_cmdline, " ", -1);
-      _ostree_kernel_args_append_argv (kargs, proc_cmdline_args);
     }
   else if (merge_deployment)
     {

src/ostree/ot-admin-instutil-builtin-set-kargs.c

@@ -27,7 +27,18 @@
 
 #include "otutil.h"
 
+#include "../libostree/ostree-kernel-args.h"
+
+static gboolean opt_proc_cmdline;
+static gboolean opt_merge;
+static char **opt_replace;
+static char **opt_append;
+
 static GOptionEntry options[] = {
+  { "import-proc-cmdline", 0, 0, G_OPTION_ARG_NONE, &opt_proc_cmdline, "Import current /proc/cmdline", NULL },
+  { "merge", 0, 0, G_OPTION_ARG_NONE, &opt_merge, "Merge with previous command line", NULL },
+  { "replace", 0, 0, G_OPTION_ARG_STRING_ARRAY, &opt_replace, "Set kernel argument, like root=/dev/sda1; this overrides any earlier argument with the same name", "KEY=VALUE" },
+  { "append", 0, 0, G_OPTION_ARG_STRING_ARRAY, &opt_append, "Append kernel argument; useful with e.g. console= that can be used multiple times", "KEY=VALUE" },
   { NULL }
 };
 
@@ -39,7 +50,7 @@ ot_admin_instutil_builtin_set_kargs (int argc, char **argv, OstreeSysroot *sysro
   gs_unref_ptrarray GPtrArray *deployments = NULL;
   OstreeDeployment *first_deployment = NULL;
   GOptionContext *context = NULL;
-  gs_unref_ptrarray GPtrArray *new_kargs = NULL;
+  __attribute__((cleanup(_ostree_kernel_args_cleanup))) OstreeKernelArgs *kargs = NULL;
 
   context = g_option_context_new ("ARGS - set new kernel command line arguments");
 
@@ -60,15 +71,45 @@ ot_admin_instutil_builtin_set_kargs (int argc, char **argv, OstreeSysroot *sysro
     }
   first_deployment = deployments->pdata[0];
 
-  new_kargs = g_ptr_array_new ();
+  kargs = _ostree_kernel_args_new ();
+
+  /* If they want the current kernel's args, they very likely don't
+   * want the ones from the merge.
+   */
+  if (opt_proc_cmdline)
+    {
+      if (!_ostree_kernel_args_append_proc_cmdline (kargs, cancellable, error))
+        goto out;
+    }
+  else if (opt_merge)
+    {
+      OstreeBootconfigParser *bootconfig = ostree_deployment_get_bootconfig (first_deployment);
+      gs_strfreev char **previous_args = g_strsplit (ostree_bootconfig_parser_get (bootconfig, "options"), " ", -1);
+
+      _ostree_kernel_args_append_argv (kargs, previous_args);
+    }
+
+  if (opt_replace)
+    {
+      _ostree_kernel_args_replace_argv (kargs, opt_replace);
+    }
+
+  if (opt_append)
+    {
+      _ostree_kernel_args_append_argv (kargs, opt_append);
+    }
+
   for (i = 1; i < argc; i++)
-    g_ptr_array_add (new_kargs, argv[i]);
-  g_ptr_array_add (new_kargs, NULL);
-  
-  if (!ostree_sysroot_deployment_set_kargs (sysroot, first_deployment,
-                                            (char**)new_kargs->pdata,
-                                            cancellable, error))
-    goto out;
+    _ostree_kernel_args_append (kargs, argv[i]);
+
+  {
+    gs_strfreev char **kargs_strv = _ostree_kernel_args_to_strv (kargs);
+
+    if (!ostree_sysroot_deployment_set_kargs (sysroot, first_deployment,
+                                              kargs_strv,
+                                              cancellable, error))
+      goto out;
+  }
 
   ret = TRUE;
  out: