Skip to content

Commit

Permalink
confile: add lxc.hook.version
Browse files Browse the repository at this point in the history 
Unblocks lxc#2015.
Closes lxc#1766.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
  • Loading branch information
Christian Brauner committed Dec 10, 2017
1 parent 41d6817 commit 8aaa4b4
Show file tree
Hide file tree
Showing 5 changed files with 101 additions and 16 deletions.
44 changes: 36 additions & 8 deletions doc/lxc.container.conf.sgml.in
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1584,9 +1584,10 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
at various times in a container's lifetime.
</para>
<para>
When a container hook is executed, information is passed both
as command line arguments and through environment variables.
The arguments are:
When a container hook is executed, additional information is passed
along. The <option>lxc.hook.version</option> argument can be used to
determine if the following arguments are passed as command line
arguments or through environment variables. The arguments are:
<itemizedlist>
<listitem><para> Container name. </para></listitem>
<listitem><para> Section (always 'lxc'). </para></listitem>
Expand All @@ -1600,20 +1601,47 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
</itemizedlist>
The following environment variables are set:
<itemizedlist>
<listitem><para> LXC_CGNS_AWARE: indicated whether the container is
cgroup namespace aware. </para></listitem>
<listitem><para> LXC_CONFIG_FILE: the path to the container
configuration file. </para></listitem>
<listitem><para> LXC_HOOK_ARGS: the container name, secion type
(always 'lxc') and the hook type (i.e. 'clone' or 'pre-mount'). Note
that the existence of this environment variable is conditional on the
value of <option>lxc.hook.version</option>. If it is set to 1 then
LXC_HOOK_ARGS will be set.
</para></listitem>
<listitem><para> LXC_LOG_LEVEL: the container's log level. </para></listitem>
<listitem><para> LXC_NAME: is the container's name. </para></listitem>
<listitem><para> LXC_ROOTFS_MOUNT: the path to the mounted root filesystem. </para></listitem>
<listitem><para> LXC_CONFIG_FILE: the path to the container configuration file. </para></listitem>
<listitem><para> LXC_SRC_NAME: in the case of the clone hook, this is the original container's name. </para></listitem>
<listitem><para> LXC_ROOTFS_PATH: this is the lxc.rootfs.path entry for the container. Note this is likely not where the mounted rootfs is to be found, use LXC_ROOTFS_MOUNT for that. </para></listitem>
<listitem><para> LXC_CGNS_AWARE: indicated whether the container is cgroup namespace aware. </para></listitem>
<listitem><para> LXC_LOG_LEVEL: the container's log level. </para></listitem>
<listitem><para> LXC_ROOTFS_PATH: this is the lxc.rootfs.path entry
for the container. Note this is likely not where the mounted rootfs is
to be found, use LXC_ROOTFS_MOUNT for that. </para></listitem>
<listitem><para> LXC_SRC_NAME: in the case of the clone hook, this is
the original container's name. </para></listitem>
</itemizedlist>
</para>
<para>
Standard output from the hooks is logged at debug level.
Standard error is not logged, but can be captured by the
hook redirecting its standard error to standard output.
</para>
<variablelist>
<varlistentry>
<term>
<option>lxc.hook.version</option>
</term>
<listitem>
<para>
To pass the arguments in new style via environment variables set to
1 otherwise set to 0 to pass them as arguments.
This setting affects the container name, section (always 'lxc') and
the hook type (i.e. 'clone' or 'pre-mount') which are passed via
LXC_HOOK_ARGS when 1 is set.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist>
<varlistentry>
<term>
Expand Down
1 change: 1 addition & 0 deletions src/lxc/conf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2416,6 +2416,7 @@ struct lxc_conf *lxc_conf_init(void)
lxc_list_init(&new->aliens);
lxc_list_init(&new->environment);
lxc_list_init(&new->limits);
new->hooks_version = 0;
for (i = 0; i < NUM_LXC_HOOKS; i++)
lxc_list_init(&new->hooks[i]);
lxc_list_init(&new->groups);
Expand Down
6 changes: 5 additions & 1 deletion src/lxc/conf.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -275,7 +275,11 @@ struct lxc_conf {
struct lxc_rootfs rootfs;
char *ttydir;
int close_all_fds;
struct lxc_list hooks[NUM_LXC_HOOKS];

struct {
unsigned int hooks_version;
struct lxc_list hooks[NUM_LXC_HOOKS];
};

char *lsm_aa_profile;
unsigned int lsm_aa_allow_incomplete;
Expand Down
43 changes: 41 additions & 2 deletions src/lxc/confile.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -92,6 +92,7 @@ lxc_config_define(ephemeral);
lxc_config_define(execute_cmd);
lxc_config_define(group);
lxc_config_define(hooks);
lxc_config_define(hooks_version);
lxc_config_define(idmaps);
lxc_config_define(includefiles);
lxc_config_define(init_cmd);
Expand Down Expand Up @@ -166,11 +167,12 @@ static struct lxc_config_t config[] = {
{ "lxc.hook.destroy", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.mount", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.post-stop", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.start-host", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.pre-start", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.pre-mount", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.pre-start", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.start", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.start-host", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.stop", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.version", false, set_config_hooks_version, get_config_hooks_version, clr_config_hooks_version, },
{ "lxc.hook", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.idmap", false, set_config_idmaps, get_config_idmaps, clr_config_idmaps, },
{ "lxc.include", false, set_config_includefiles, get_config_includefiles, clr_config_includefiles, },
Expand Down Expand Up @@ -976,6 +978,29 @@ static int set_config_hooks(const char *key, const char *value,
return -1;
}

static int set_config_hooks_version(const char *key, const char *value,
struct lxc_conf *lxc_conf, void *data)
{
int ret;
unsigned int tmp;

if (lxc_config_value_empty(value))
return clr_config_hooks_version(key, lxc_conf, NULL);

ret = lxc_safe_uint(value, &tmp);
if (ret < 0)
return -1;

if (tmp > 1) {
ERROR("Invalid hook version specified. Currently only 0 "
"(legacy) and 1 are supported");
return -1;
}

lxc_conf->hooks_version = tmp;
return 0;
}

static int set_config_personality(const char *key, const char *value,
struct lxc_conf *lxc_conf, void *data)
{
Expand Down Expand Up @@ -3036,6 +3061,12 @@ static int get_config_hooks(const char *key, char *retv, int inlen,
return fulllen;
}

static int get_config_hooks_version(const char *key, char *retv, int inlen,
struct lxc_conf *c, void *data)
{
return lxc_get_conf_int(c, retv, inlen, c->hooks_version);
}

static int get_config_net(const char *key, char *retv, int inlen,
struct lxc_conf *c, void *data)
{
Expand Down Expand Up @@ -3499,6 +3530,14 @@ static inline int clr_config_hooks(const char *key, struct lxc_conf *c,
return lxc_clear_hooks(c, key);
}

static inline int clr_config_hooks_version(const char *key, struct lxc_conf *c,
void *data)
{
/* default to legacy hooks version */
c->hooks_version = 0;
return 0;
}

static inline int clr_config_net(const char *key, struct lxc_conf *c,
void *data)
{
Expand Down
23 changes: 18 additions & 5 deletions src/tests/parse_config_file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -301,16 +301,16 @@ static int set_get_compare_clear_save_load_network(

int main(int argc, char *argv[])
{
int ret;
struct lxc_container *c;
int fd = -1;
int ret = EXIT_FAILURE;
int fd = -1, fret = EXIT_FAILURE;
char tmpf[] = "lxc-parse-config-file-XXXXXX";
char retval[4096] = {0};

fd = mkstemp(tmpf);
if (fd < 0) {
lxc_error("%s\n", "Could not create temporary file");
exit(ret);
exit(fret);
}
close(fd);

Expand Down Expand Up @@ -1096,10 +1096,23 @@ int main(int argc, char *argv[])
goto non_test_error;
}

ret = EXIT_SUCCESS;
ret = set_get_compare_clear_save_load(c, "lxc.hook.version", "1", tmpf, true);
if (ret < 0) {
lxc_error("%s\n", "lxc.hook.version");
goto non_test_error;
}

ret = set_get_compare_clear_save_load(c, "lxc.hook.version", "2", tmpf, true);
if (ret == 0) {
lxc_error("%s\n", "lxc.hook.version");
goto non_test_error;
}

fret = EXIT_SUCCESS;

non_test_error:
(void)unlink(tmpf);
(void)rmdir(dirname(c->configfile));
lxc_container_put(c);
exit(ret);
exit(fret);
}

0 comments on commit 8aaa4b4

Please sign in to comment.