Add support for default kargs files

Instead of merging kargs from the previous deployment, by default
regenerate kargs from the following config files:

/etc/ostree/kargs (host config)
/usr/lib/ostree-boot/kargs (base config)

The base config is sourced from the repo at the commit (revision)
being deployed, so that newly committed kargs will take effect
immediately after upgrading. The host config is sourced from the
previous deployment (merge deployment), so that host edits are
reflected.

Kernel arguments present in the base config are appended to
kernel arguments in the base config.

Using the commands that modify kargs (of the form `ostree admin
deploy --karg*" will cause kargs in later deployments to be copied
from the merge deployment, rather than regenerate from the config
files.

Makefile-tests.am

@@ -98,6 +98,7 @@ _installed_or_uninstalled_test_scripts = \
 	tests/test-admin-deploy-syslinux.sh \
 	tests/test-admin-deploy-2.sh \
 	tests/test-admin-deploy-karg.sh \
+	tests/test-admin-deploy-karg-default.sh \
 	tests/test-admin-deploy-switch.sh \
 	tests/test-admin-deploy-etcmerge-cornercases.sh \
 	tests/test-admin-deploy-uboot.sh \

src/libostree/ostree-sysroot-deploy.c

@@ -2568,9 +2568,107 @@ get_var_dfd (OstreeSysroot      *self,
   return glnx_opendirat (base_dfd, base_path, TRUE, ret_fd, error);
 }
 
+static gboolean
+load_file_from_deployment_allow_noent (OstreeSysroot     *sysroot,
+                                       OstreeDeployment  *deployment,
+                                       char              *path,
+                                       char             **contents_out,
+                                       GCancellable      *cancellable,
+                                       GError           **error)
+{
+  glnx_autofd int deployment_dfd = -1;
+  g_autofree char *deployment_path = ostree_sysroot_get_deployment_dirpath (sysroot, deployment);
+  if (!glnx_opendirat (sysroot->sysroot_fd, deployment_path, TRUE,
+                       &deployment_dfd, error))
+    return FALSE;
+
+  struct stat stbuf;
+  if (!glnx_fstatat_allow_noent (deployment_dfd, path, &stbuf, 0, error))
+    return FALSE;
+  const gboolean config_exists = (errno == 0);
+
+  g_autofree char *ret_contents = NULL;
+  if (config_exists)
+    {
+      ret_contents = glnx_file_get_contents_utf8_at (deployment_dfd,
+                                                     path,
+                                                     NULL,
+                                                     cancellable,
+                                                     error);
+      if (!ret_contents)
+        return FALSE;
+    }
+
+  *contents_out = g_steal_pointer (&ret_contents);
+
+  return TRUE;
+}
+
+/* Get a GFile* referring to the commit object at ref for the file at path. */
+static GFile*
+get_file_from_repo (OstreeRepo    *repo,
+                    const char    *ref,
+                    const char    *path,
+                    GCancellable  *cancellable,
+                    GError       **error)
+{
+  g_autoptr(GFile) root = NULL;
+  if (!ostree_repo_read_commit (repo, ref, &root,
+                                NULL, cancellable, error))
+    return NULL;
+  return g_file_resolve_relative_path (root, path);
+}
+
+static gboolean
+sysroot_regenerate_kargs (OstreeSysroot     *self,
+                          const char        *revision,
+                          OstreeDeployment  *deployment,
+                          char             **kargs_out,
+                          GCancellable      *cancellable,
+                          GError           **error)
+{
+  g_autoptr(GPtrArray) kargs_configs = g_ptr_array_new_with_free_func (g_free);
+
+  /* Load host kargs configuration from the merge deployment, so that any
+   * configuration done on the host is carried to the next deployment. */
+  g_autofree char *host_karg_contents = NULL;
+  if (!load_file_from_deployment_allow_noent (self, deployment,
+                                              _OSTREE_SYSROOT_KARGS_HOST,
+                                              &host_karg_contents,
+                                              cancellable, error))
+    return FALSE;
+  if (host_karg_contents)
+    g_ptr_array_add (kargs_configs, g_strstrip (g_steal_pointer (&host_karg_contents)));
+
+  /* Load base kargs configuration from the current commit, so that kargs will
+   * be written to the bootconfig as soon as the current deployment is
+   * finished (in install_deployment_kernel()). */
+  g_autofree char *base_karg_contents = NULL;
+  g_autoptr(GFile) base_karg_file = get_file_from_repo (ostree_sysroot_repo (self),
+                                                        revision,
+                                                        _OSTREE_SYSROOT_KARGS_BASE,
+                                                        cancellable, error);
+  if (!ot_file_load_contents_allow_not_found (base_karg_file, &base_karg_contents,
+                                              cancellable, error))
+    return FALSE;
+  if (base_karg_contents)
+    g_ptr_array_add (kargs_configs, g_strstrip (g_steal_pointer (&base_karg_contents)));
+
+  g_autoptr(OstreeKernelArgs) kargs = _ostree_kernel_args_new ();
+  for (guint i = 0; i < kargs_configs->len; i++)
+    _ostree_kernel_args_parse_append (kargs, kargs_configs->pdata[i]);
+
+  g_autofree char *kargs_contents = _ostree_kernel_args_to_string (kargs);
+
+  *kargs_out = g_steal_pointer (&kargs_contents);
+
+  return TRUE;
+}
+
 static gboolean
 sysroot_finalize_deployment (OstreeSysroot     *self,
                              OstreeDeployment  *deployment,
+                             const char        *revision,
                              char             **override_kernel_argv,
                              OstreeDeployment  *merge_deployment,
                              GCancellable      *cancellable,
@@ -2581,8 +2679,9 @@ sysroot_finalize_deployment (OstreeSysroot     *self,
   if (!glnx_opendirat (self->sysroot_fd, deployment_path, TRUE, &deployment_dfd, error))
     return FALSE;
 
-  /* If we didn't get an override in this deployment, copy kargs directly from
-   * the merge deployment. */
+  /* If we didn't get an override in this deployment, decide whether to copy
+   * kargs directly from the merge deployment, or regenerate kargs from the
+   * default config files. */
   if (!override_kernel_argv)
     {
       OstreeBootconfigParser *merge_bootconfig = NULL;
@@ -2591,16 +2690,27 @@ sysroot_finalize_deployment (OstreeSysroot     *self,
         {
           merge_bootconfig = ostree_deployment_get_bootconfig (merge_deployment);
           if (merge_bootconfig)
+            kargs_overridden = g_strcmp0 (ostree_bootconfig_parser_get (merge_bootconfig, "ostree-kargs-override"),
+                                          "true") == 0;
+        }
+
+      if (kargs_overridden)
+        {
+          /* Copy kargs from the merge deployment. */
+          g_assert (merge_bootconfig);
+          const char *opts = ostree_bootconfig_parser_get (merge_bootconfig, "options");
+          ostree_bootconfig_parser_set (ostree_deployment_get_bootconfig (deployment), "options", opts);
+          ostree_bootconfig_parser_set (ostree_deployment_get_bootconfig (deployment), "ostree-kargs-override", "true");
+        }
+      else
+        {
+          /* Regenerate kargs from the default config files. */
+          g_autofree char *opts = NULL;
+          if (merge_deployment)
             {
-              /* Copy kargs from the merge deployment. */
-              const char *opts = ostree_bootconfig_parser_get (merge_bootconfig, "options");
+              if (!sysroot_regenerate_kargs (self, revision, merge_deployment, &opts, cancellable, error))
+                return FALSE;
               ostree_bootconfig_parser_set (ostree_deployment_get_bootconfig (deployment), "options", opts);
-              kargs_overridden = g_strcmp0 (ostree_bootconfig_parser_get (merge_bootconfig, "ostree-kargs-override"),
-                                            "true") == 0;
-            }
-          if (kargs_overridden)
-            {
-              ostree_bootconfig_parser_set (ostree_deployment_get_bootconfig (deployment), "ostree-kargs-override", "true");
             }
         }
     }
@@ -2691,7 +2801,8 @@ ostree_sysroot_deploy_tree (OstreeSysroot     *self,
                                       &deployment, cancellable, error))
     return FALSE;
 
-  if (!sysroot_finalize_deployment (self, deployment, override_kernel_argv,
+  if (!sysroot_finalize_deployment (self, deployment, revision,
+                                    override_kernel_argv,
                                     provided_merge_deployment,
                                     cancellable, error))
     return FALSE;
@@ -2950,8 +3061,8 @@ _ostree_sysroot_finalize_staged (OstreeSysroot *self,
   if (!glnx_unlinkat (AT_FDCWD, _OSTREE_SYSROOT_RUNSTATE_STAGED, 0, error))
     return FALSE;
 
-  if (!sysroot_finalize_deployment (self, self->staged_deployment, kargs, merge_deployment,
-                                    cancellable, error))
+  if (!sysroot_finalize_deployment (self, self->staged_deployment, self->staged_deployment->csum,
+                                    kargs, merge_deployment, cancellable, error))
     return FALSE;
 
   /* Now, take ownership of the staged state, as normally the API below strips

src/libostree/ostree-sysroot-private.h

@@ -78,6 +78,8 @@ struct OstreeSysroot {
 #define _OSTREE_SYSROOT_RUNSTATE_STAGED "/run/ostree/staged-deployment"
 #define _OSTREE_SYSROOT_DEPLOYMENT_RUNSTATE_DIR "/run/ostree/deployment-state/"
 #define _OSTREE_SYSROOT_DEPLOYMENT_RUNSTATE_FLAG_DEVELOPMENT "unlocked-development"
+#define _OSTREE_SYSROOT_KARGS_HOST "etc/ostree/kargs"
+#define _OSTREE_SYSROOT_KARGS_BASE "usr/lib/ostree-boot/kargs"
 
 void
 _ostree_sysroot_emit_journal_msg (OstreeSysroot  *self,

src/libotutil/ot-gio-utils.c

@@ -177,3 +177,39 @@ ot_file_get_path_cached (GFile *file)
 
   return path;
 }
+
+/**
+ * ot_file_load_contents_allow_not_found:
+ *
+ * Load the contents of file, allowing G_IO_ERROR_NOT_FOUND.
+ * If file exists, return the contents in out_contents (otherwise out_contents
+ * holds NULL).
+ *
+ * Return FALSE for any other error.
+ */
+gboolean
+ot_file_load_contents_allow_not_found (GFile         *file,
+                                       char         **out_contents,
+                                       GCancellable  *cancellable,
+                                       GError       **error)
+{
+  g_return_val_if_fail (file != NULL, FALSE);
+
+  GError *local_error = NULL;
+  g_autofree char *ret_contents = NULL;
+  if (!g_file_load_contents (file, cancellable, &ret_contents, NULL, NULL, &local_error))
+    {
+      if (g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
+        {
+          g_clear_error (&local_error);
+        }
+      else
+        {
+          g_propagate_error (error, local_error);
+          return FALSE;
+        }
+    }
+
+  ot_transfer_out_value (out_contents, &ret_contents);
+  return TRUE;
+}

src/libotutil/ot-gio-utils.h

@@ -79,4 +79,10 @@ gs_file_get_path_cached (GFile *file)
   return ot_file_get_path_cached (file);
 }
 
+gboolean
+ot_file_load_contents_allow_not_found (GFile         *file,
+                                       char         **out_contents,
+                                       GCancellable  *cancellable,
+                                       GError       **error);
+
 G_END_DECLS

tests/libtest.sh

@@ -512,6 +512,55 @@ os_repository_new_commit ()
     cd ${test_tmpdir}
 }
 
+os_repository_commit ()
+{
+    repo=${1:-testos-repo}
+    boot_checksum_iteration=${2:-0}
+    content_iteration=${3:-0}
+    branch=${4:-testos/buildmaster/x86_64-runtime}
+    export version=${5:-$(date "+%Y%m%d.${content_iteration}")}
+    echo "BOOT ITERATION: $boot_checksum_iteration"
+    cd ${test_tmpdir}/osdata
+    kver=3.6.0
+    if test -f usr/lib/modules/${kver}/vmlinuz; then
+        bootdir=usr/lib/modules/${kver}
+    else
+        if test -d usr/lib/ostree-boot; then
+            bootdir=usr/lib/ostree-boot
+        else
+            bootdir=boot
+        fi
+    fi
+    rm ${bootdir}/*
+    kernel_path=${bootdir}/vmlinuz
+    initramfs_path=${bootdir}/initramfs.img
+    if [[ $bootdir != usr/lib/modules/* ]]; then
+        kernel_path=${kernel_path}-${kver}
+        initramfs_path=${bootdir}/initramfs-${kver}.img
+    fi
+    echo "new: a kernel ${boot_checksum_iteration}" > ${kernel_path}
+    echo "new: an initramfs ${boot_checksum_iteration}" > ${initramfs_path}
+    bootcsum=$(cat ${kernel_path} ${initramfs_path} | sha256sum | cut -f 1 -d ' ')
+    export bootcsum
+    if [[ $bootdir != usr/lib/modules/* ]]; then
+        mv ${kernel_path}{,-${bootcsum}}
+        mv ${initramfs_path}{,-${bootcsum}}
+    fi
+
+    commithash=$(${CMD_PREFIX} ostree --repo=${test_tmpdir}/${repo} commit  --add-metadata-string "version=${version}" -b $branch -s "Build")
+    export commithash
+    cd ${test_tmpdir}
+}
+
+os_tree_write_file ()
+{
+    path=${1}
+    contents="${2}"
+    cd ${test_tmpdir}/osdata
+    echo "${contents}" > ${path}
+    cd ${test_tmpdir}
+}
+
 _have_user_xattrs=''
 have_user_xattrs() {
     assert_has_setfattr

tests/test-admin-deploy-karg-default.sh

@@ -0,0 +1,76 @@
+#!/bin/bash
+#
+# Copyright (C) 2019 Robert Fairley <[email protected]>
+#
+# SPDX-License-Identifier: LGPL-2.0+
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+set -euo pipefail
+
+. $(dirname $0)/libtest.sh
+
+# Exports OSTREE_SYSROOT so --sysroot not needed.
+setup_os_repository "archive" "syslinux"
+
+echo "1..1"
+
+${CMD_PREFIX} ostree --repo=sysroot/ostree/repo pull-local --remote=testos testos-repo testos/buildmaster/x86_64-runtime
+
+${CMD_PREFIX} ostree admin deploy --os=testos testos:testos/buildmaster/x86_64-runtime
+assert_has_dir sysroot/boot/ostree/testos-${bootcsum}
+
+# Configure kargs stored in the ostree commit.
+mkdir -p osdata/usr/lib/ostree-boot
+os_tree_write_file "usr/lib/ostree-boot/kargs" "FOO=USR_1 MOO=USR_2 WOO=USR_3"
+os_repository_commit "testos-repo"
+
+# Upgrade to tree with newly-committed kargs file.
+${CMD_PREFIX} ostree --repo=sysroot/ostree/repo remote add --set=gpg-verify=false testos file://$(pwd)/testos-repo testos/buildmaster/x86_64-runtime
+${CMD_PREFIX} ostree admin upgrade --os=testos
+# Sanity check a new boot directory was created after upgrading.
+assert_has_dir sysroot/boot/ostree/testos-${bootcsum}
+
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'FOO=USR_1'
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'MOO=USR_2'
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'WOO=USR_3'
+assert_not_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'ostree-kargs-override'
+
+# Configure kargs through the host config file.
+rev=$(${CMD_PREFIX} ostree --repo=sysroot/ostree/repo rev-parse testos/buildmaster/x86_64-runtime)
+export rev
+echo "rev=${rev}"
+etc=sysroot/ostree/deploy/testos/deploy/${rev}.0/etc
+assert_has_dir ${etc}
+mkdir -p ${etc}/ostree
+echo "HELLO=ETC_1 MELLO=ETC_2 BELLO=ETC_3" > ${etc}/ostree/kargs
+
+# Re-deploy with host-configured kernel args.
+${CMD_PREFIX} ostree admin deploy --os=testos testos:testos/buildmaster/x86_64-runtime
+
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'HELLO=ETC_1'
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'MELLO=ETC_2'
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'BELLO=ETC_3'
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'FOO=USR_1'
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'MOO=USR_2'
+assert_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'WOO=USR_3'
+assert_not_file_has_content sysroot/boot/loader/entries/ostree-2-testos.conf 'ostree-kargs-override'
+
+echo "ok default kargs"
+
+# Tests needed:
+# - downgrading
+# - staging a deployment