[lxc-devel] [PATCH 3/4] Re-organize API for global lxc.conf config

Stéphane Graber stgraber at ubuntu.com
Thu Jan 9 23:33:06 UTC 2014


Instead of having one function for each possible key in lxc.conf which
doesn't really scale and requires an API update for every new key,
switch to a generic lxc_get_global_config_item() function which takes a
key name as argument.

Signed-off-by: Stéphane Graber <stgraber at ubuntu.com>
---
 src/lua-lxc/core.c             |  2 +-
 src/lxc/arguments.c            |  2 +-
 src/lxc/bdev.c                 | 12 ++++++------
 src/lxc/cgroup.c               |  2 +-
 src/lxc/commands.c             |  2 +-
 src/lxc/conf.c                 |  2 +-
 src/lxc/log.c                  |  2 +-
 src/lxc/lxc_config.c           | 12 ++++++------
 src/lxc/lxccontainer.c         | 25 +++++--------------------
 src/lxc/lxccontainer.h         | 41 +++++------------------------------------
 src/lxc/start.c                |  2 +-
 src/lxc/utils.c                | 32 +-------------------------------
 src/lxc/utils.h                | 12 ++----------
 src/python-lxc/lxc.c           | 15 +++++++++++----
 src/python-lxc/lxc/__init__.py |  2 +-
 src/tests/snapshot.c           |  4 ++--
 16 files changed, 46 insertions(+), 123 deletions(-)

diff --git a/src/lua-lxc/core.c b/src/lua-lxc/core.c
index aa5831c..ae8ab01 100644
--- a/src/lua-lxc/core.c
+++ b/src/lua-lxc/core.c
@@ -412,7 +412,7 @@ static int lxc_version_get(lua_State *L) {
 }
 
 static int lxc_default_config_path_get(lua_State *L) {
-    const char *lxcpath = lxc_get_default_config_path();
+    const char *lxcpath = lxc_get_global_config_item("lxc.lxcpath");
 
     lua_pushstring(L, lxcpath);
     return 1;
diff --git a/src/lxc/arguments.c b/src/lxc/arguments.c
index bdde2f7..aaf9634 100644
--- a/src/lxc/arguments.c
+++ b/src/lxc/arguments.c
@@ -222,7 +222,7 @@ extern int lxc_arguments_parse(struct lxc_arguments *args,
 
 	/* If no lxcpaths were given, use default */
 	if (!args->lxcpath_cnt) {
-		ret = lxc_arguments_lxcpath_add(args, default_lxc_path());
+		ret = lxc_arguments_lxcpath_add(args, lxc_global_config_value("lxc.lxcpath"));
 		if (ret < 0)
 			return ret;
 	}
diff --git a/src/lxc/bdev.c b/src/lxc/bdev.c
index 30b9574..a655756 100644
--- a/src/lxc/bdev.c
+++ b/src/lxc/bdev.c
@@ -565,7 +565,7 @@ static int zfs_clone(const char *opath, const char *npath, const char *oname,
 			return -1;
 		*p = '\0';
 	} else
-		zfsroot = default_zfs_root();
+		zfsroot = lxc_global_config_value("lxc.zfsroot");
 
 	ret = snprintf(option, MAXPATHLEN, "-omountpoint=%s/%s/rootfs",
 		lxcpath, nname);
@@ -695,7 +695,7 @@ static int zfs_create(struct bdev *bdev, const char *dest, const char *n,
 	pid_t pid;
 
 	if (!specs || !specs->zfs.zfsroot)
-		zfsroot = default_zfs_root();
+		zfsroot = lxc_global_config_value("lxc.zfsroot");
 	else
 		zfsroot = specs->zfs.zfsroot;
 
@@ -982,7 +982,7 @@ static int lvm_clonepaths(struct bdev *orig, struct bdev *new, const char *oldna
 				orig->type);
 			return -1;
 		}
-		vg = default_lvm_vg();
+		vg = lxc_global_config_value("lxc.lvm_vg");
 		len = strlen("/dev/") + strlen(vg) + strlen(cname) + 2;
 		if ((new->src = malloc(len)) == NULL)
 			return -1;
@@ -1032,7 +1032,7 @@ static int lvm_clonepaths(struct bdev *orig, struct bdev *new, const char *oldna
 			return -1;
 		}
 	} else {
-		if (do_lvm_create(new->src, size, default_lvm_thin_pool()) < 0) {
+		if (do_lvm_create(new->src, size, lxc_global_config_value("lxc.lvm_thin_pool")) < 0) {
 			ERROR("Error creating new lvm blockdev");
 			return -1;
 		}
@@ -1071,11 +1071,11 @@ static int lvm_create(struct bdev *bdev, const char *dest, const char *n,
 
 	vg = specs->lvm.vg;
 	if (!vg)
-		vg = default_lvm_vg();
+		vg = lxc_global_config_value("lxc.lvm_vg");
 
 	thinpool = specs->lvm.thinpool;
 	if (!thinpool)
-		thinpool = default_lvm_thin_pool();
+		thinpool = lxc_global_config_value("lxc.lvm_thin_pool");
 
 	/* /dev/$vg/$lv */
 	if (specs->lvm.lv)
diff --git a/src/lxc/cgroup.c b/src/lxc/cgroup.c
index 946ab0e..b1196b4 100644
--- a/src/lxc/cgroup.c
+++ b/src/lxc/cgroup.c
@@ -89,7 +89,7 @@ struct cgroup_meta_data *lxc_cgroup_load_meta()
 	int saved_errno;
 
 	errno = 0;
-	cgroup_use = default_cgroup_use();
+	cgroup_use = lxc_global_config_value("lxc.cgroup.use");
 	if (!cgroup_use && errno != 0)
 		return NULL;
 	if (cgroup_use) {
diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index 07e64b6..e993f2e 100644
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -80,7 +80,7 @@ static int fill_sock_name(char *path, int len, const char *name,
 	int ret;
 
 	if (!inpath) {
-		lxcpath = default_lxc_path();
+		lxcpath = lxc_global_config_value("lxc.lxcpath");
 		if (!lxcpath) {
 			ERROR("Out of memory getting lxcpath");
 			return -1;
diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index a386d94..7e0eddd 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -1921,7 +1921,7 @@ static int mount_entry_on_absolute_rootfs(const struct mntent *mntent,
 		return -1;
 	}
 
-	lxcpath = default_lxc_path();
+	lxcpath = lxc_global_config_value("lxc.lxcpath");
 	if (!lxcpath) {
 		ERROR("Out of memory");
 		return -1;
diff --git a/src/lxc/log.c b/src/lxc/log.c
index 86f7cd4..b09885c 100644
--- a/src/lxc/log.c
+++ b/src/lxc/log.c
@@ -324,7 +324,7 @@ extern int lxc_log_init(const char *name, const char *file,
 			lxcpath = LOGPATH;
 
 		/* try LOGPATH if lxcpath is the default */
-		if (strcmp(lxcpath, default_lxc_path()) == 0)
+		if (strcmp(lxcpath, lxc_global_config_value("lxc.lxcpath")) == 0)
 			ret = _lxc_log_set_file(name, NULL, 0);
 
 		/* try in lxcpath */
diff --git a/src/lxc/lxc_config.c b/src/lxc/lxc_config.c
index dcb3a3b..c4797b5 100644
--- a/src/lxc/lxc_config.c
+++ b/src/lxc/lxc_config.c
@@ -27,15 +27,15 @@
 
 struct lxc_config_items {
 	char *name;
-	const char *(*fn)(void);
 };
 
 static struct lxc_config_items items[] =
 {
-	{ .name = "lxc.lxcpath", .fn = &lxc_get_default_config_path, },
-	{ .name = "lxc.lvm_vg", .fn = &lxc_get_default_lvm_vg, },
-	{ .name = "lxc.lvm_thin_pool", .fn = &lxc_get_default_lvm_thin_pool, },
-	{ .name = "lxc.zfsroot", .fn = &lxc_get_default_zfs_root, },
+	{ .name = "lxc.default_config", },
+	{ .name = "lxc.lxcpath", },
+	{ .name = "lxc.lvm_vg", },
+	{ .name = "lxc.lvm_thin_pool", },
+	{ .name = "lxc.zfsroot", },
 	{ .name = NULL, },
 };
 
@@ -65,7 +65,7 @@ int main(int argc, char *argv[])
 		list_config_items();
 	for (i = &items[0]; i->name; i++) {
 		if (strcmp(argv[1], i->name) == 0) {
-			printf("%s\n", i->fn());
+			printf("%s\n", lxc_get_global_config_item(i->name));
 			exit(0);
 		}
 	}
diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index f999cfc..faa0a9f 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -2035,24 +2035,9 @@ static int lxcapi_get_cgroup_item(struct lxc_container *c, const char *subsys, c
 	return ret;
 }
 
-const char *lxc_get_default_config_path(void)
+const char *lxc_get_global_config_item(const char *key)
 {
-	return default_lxc_path();
-}
-
-const char *lxc_get_default_lvm_vg(void)
-{
-	return default_lvm_vg();
-}
-
-const char *lxc_get_default_lvm_thin_pool(void)
-{
-	return default_lvm_thin_pool();
-}
-
-const char *lxc_get_default_zfs_root(void)
-{
-	return default_zfs_root();
+	return lxc_global_config_value(key);
 }
 
 const char *lxc_get_version(void)
@@ -3035,7 +3020,7 @@ struct lxc_container *lxc_container_new(const char *name, const char *configpath
 	if (configpath)
 		c->config_path = strdup(configpath);
 	else
-		c->config_path = strdup(default_lxc_path());
+		c->config_path = strdup(lxc_global_config_value("lxc.lxcpath"));
 
 	if (!c->config_path) {
 		fprintf(stderr, "Out of memory");
@@ -3157,7 +3142,7 @@ int list_defined_containers(const char *lxcpath, char ***names, struct lxc_conta
 	struct lxc_container *c;
 
 	if (!lxcpath)
-		lxcpath = default_lxc_path();
+		lxcpath = lxc_global_config_value("lxc.lxcpath");
 
 	dir = opendir(lxcpath);
 	if (!dir) {
@@ -3247,7 +3232,7 @@ int list_active_containers(const char *lxcpath, char ***nret,
 	struct lxc_container *c;
 
 	if (!lxcpath)
-		lxcpath = default_lxc_path();
+		lxcpath = lxc_global_config_value("lxc.lxcpath");
 	lxcpath_len = strlen(lxcpath);
 
 	if (cret)
diff --git a/src/lxc/lxccontainer.h b/src/lxc/lxccontainer.h
index a62411b..921e47d 100644
--- a/src/lxc/lxccontainer.h
+++ b/src/lxc/lxccontainer.h
@@ -786,45 +786,14 @@ int lxc_container_put(struct lxc_container *c);
  */
 int lxc_get_wait_states(const char **states);
 
-/*!
- * \brief Determine path to default configuration file.
- *
- * \return Static string representing full path to default configuration
- *  file.
- *
- * \note Returned string must not be freed.
- */
-const char *lxc_get_default_config_path(void);
-
-/*!
- * \brief Determine default LVM volume group.
- *
- * \return Static string representing default volume group,
- *  or \c NULL on error.
- *
- * \note Returned string must not be freed.
- */
-const char *lxc_get_default_lvm_vg(void);
-
-/*!
- * \brief Determine default LVM thin pool.
- *
- * \return Static string representing default lvm thin pool,
- *  or \c NULL on error.
- *
- * \note Returned string must not be freed.
- */
-const char *lxc_get_default_lvm_thin_pool(void);
-
-/*!
- * \brief Determine default ZFS root.
+/*
+ * \brief Get the value for a global config key
  *
- * \return Static string representing default ZFS root,
- *  or \c NULL on error.
+ * \param key The name of the config key
  *
- * \note Returned string must not be freed.
+ * \return String representing the current value for the key.
  */
-const char *lxc_get_default_zfs_root(void);
+const char *lxc_get_global_config_item(const char *key);
 
 /*!
  * \brief Determine version of LXC.
diff --git a/src/lxc/start.c b/src/lxc/start.c
index a5d6e56..ce88d5f 100644
--- a/src/lxc/start.c
+++ b/src/lxc/start.c
@@ -767,7 +767,7 @@ static int lxc_spawn(struct lxc_handler *handler)
 	 * default value is available
 	 */
 	if (getuid() == 0)
-		cgroup_pattern = default_cgroup_pattern();
+		cgroup_pattern = lxc_global_config_value("lxc.cgroup.pattern");
 	if (!cgroup_pattern)
 		cgroup_pattern = "%n";
 
diff --git a/src/lxc/utils.c b/src/lxc/utils.c
index ac89da1..f860421 100644
--- a/src/lxc/utils.c
+++ b/src/lxc/utils.c
@@ -238,7 +238,7 @@ static char *copy_global_config_value(char *p)
 #define DEFAULT_THIN_POOL "lxc"
 #define DEFAULT_ZFSROOT "lxc"
 
-static const char *lxc_global_config_value(const char *option_name)
+const char *lxc_global_config_value(const char *option_name)
 {
 	static const char * const options[][2] = {
 		{ "lxc.lvm_vg",          DEFAULT_VG      },
@@ -371,36 +371,6 @@ out:
 	return values[i];
 }
 
-const char *default_lvm_vg(void)
-{
-	return lxc_global_config_value("lxc.lvm_vg");
-}
-
-const char *default_lvm_thin_pool(void)
-{
-	return lxc_global_config_value("lxc.lvm_thin_pool");
-}
-
-const char *default_zfs_root(void)
-{
-	return lxc_global_config_value("lxc.zfsroot");
-}
-
-const char *default_lxc_path(void)
-{
-	return lxc_global_config_value("lxc.lxcpath");
-}
-
-const char *default_cgroup_use(void)
-{
-	return lxc_global_config_value("lxc.cgroup.use");
-}
-
-const char *default_cgroup_pattern(void)
-{
-	return lxc_global_config_value("lxc.cgroup.pattern");
-}
-
 const char *get_rundir()
 {
 	const char *rundir;
diff --git a/src/lxc/utils.h b/src/lxc/utils.h
index 847a613..1121d74 100644
--- a/src/lxc/utils.h
+++ b/src/lxc/utils.h
@@ -41,16 +41,8 @@ extern int mkdir_p(const char *dir, mode_t mode);
 extern void remove_trailing_slashes(char *p);
 extern const char *get_rundir(void);
 
-/*
- * Return a buffer containing the default container path.
- * Caller must NOT free this buffer, since it may be static.
- */
-extern const char *default_lxc_path(void);
-extern const char *default_zfs_root(void);
-extern const char *default_lvm_vg(void);
-extern const char *default_lvm_thin_pool(void);
-extern const char *default_cgroup_use(void);
-extern const char *default_cgroup_pattern(void);
+extern const char *lxc_global_config_value(const char *option_name);
+
 /* Define getline() if missing from the C library */
 #ifndef HAVE_GETLINE
 #ifdef HAVE_FGETLN
diff --git a/src/python-lxc/lxc.c b/src/python-lxc/lxc.c
index 5ee8dd0..4381ab8 100644
--- a/src/python-lxc/lxc.c
+++ b/src/python-lxc/lxc.c
@@ -325,9 +325,16 @@ LXC_attach_run_shell(PyObject *self, PyObject *arg)
 }
 
 static PyObject *
-LXC_get_default_config_path(PyObject *self, PyObject *args)
+LXC_get_global_config_item(PyObject *self, PyObject *args, PyObject *kwds)
 {
-    return PyUnicode_FromString(lxc_get_default_config_path());
+    static char *kwlist[] = {"key", NULL};
+    char* key = NULL;
+
+    if (! PyArg_ParseTupleAndKeywords(args, kwds, "s|", kwlist,
+                                      &key))
+        return NULL;
+
+    return PyUnicode_FromString(lxc_get_global_config_item(key));
 }
 
 static PyObject *
@@ -1670,8 +1677,8 @@ static PyMethodDef LXC_methods[] = {
     {"attach_run_shell", (PyCFunction)LXC_attach_run_shell, METH_O,
      "Starts up a shell when attaching, to use as the run parameter for "
      "attach or attach_wait"},
-    {"get_default_config_path", (PyCFunction)LXC_get_default_config_path,
-     METH_NOARGS,
+    {"get_global_config_item", (PyCFunction)LXC_get_global_config_item,
+     METH_VARARGS|METH_KEYWORDS,
      "Returns the current LXC config path"},
     {"get_version", (PyCFunction)LXC_get_version, METH_NOARGS,
      "Returns the current LXC library version"},
diff --git a/src/python-lxc/lxc/__init__.py b/src/python-lxc/lxc/__init__.py
index e389abb..0ca3e54 100644
--- a/src/python-lxc/lxc/__init__.py
+++ b/src/python-lxc/lxc/__init__.py
@@ -32,7 +32,7 @@ import warnings
 warnings.warn("The python-lxc API isn't yet stable "
               "and may change at any point in the future.", Warning, 2)
 
-default_config_path = _lxc.get_default_config_path()
+default_config_path = _lxc.get_global_config_item("lxc.lxcpath")
 version = _lxc.get_version()
 
 
diff --git a/src/tests/snapshot.c b/src/tests/snapshot.c
index da7b409..fe06077 100644
--- a/src/tests/snapshot.c
+++ b/src/tests/snapshot.c
@@ -38,7 +38,7 @@ static void try_to_remove(void)
 			c->destroy(c);
 		lxc_container_put(c);
 	}
-	snprintf(snappath, 1024, "%ssnaps/%s", lxc_get_default_config_path(), MYNAME);
+	snprintf(snappath, 1024, "%ssnaps/%s", lxc_get_global_config_item("lxc.lxcpath"), MYNAME);
 	c = lxc_container_new("snap0", snappath);
 	if (c) {
 		if (c->is_defined(c))
@@ -92,7 +92,7 @@ int main(int argc, char *argv[])
 	struct stat sb;
 	int ret;
 	char path[1024];
-	snprintf(path, 1024, "%ssnaps/%s/snap0/rootfs", lxc_get_default_config_path(), MYNAME);
+	snprintf(path, 1024, "%ssnaps/%s/snap0/rootfs", lxc_get_global_config_item("lxc.lxcpath"), MYNAME);
 	ret = stat(path, &sb);
 	if (ret != 0) {
 		fprintf(stderr, "%s: %d: snapshot was not actually created\n", __FILE__, __LINE__);
-- 
1.8.5.2



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