Add a unexpanded lxc_conf

Currently when a container's configuration file has lxc.includes,
any future write_config() will expand the lxc.includes.  This
affects container clones (and snapshots) as well as users of the
API who make an update and then c.save_config().

To fix this, separately track the expanded and unexpanded lxc_conf.  The
unexpanded conf does not contain values read from lxc.includes.  The
expanded conf does.  Lxc functions mainly need the expanded conf to
figure out how to configure the container.  The unexpanded conf is used
at write_config().

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 4b52550335ef45327aa78f86c319defcc69f8316..521a48d8cf652c7041caf46b48d5c12cf9c30a46 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -2689,6 +2689,7 @@ struct lxc_conf *lxc_conf_init(void)
        lxc_list_init(&new->caps);
        lxc_list_init(&new->keepcaps);
        lxc_list_init(&new->id_map);
+       lxc_list_init(&new->includes);
        for (i=0; i<NUM_LXC_HOOKS; i++)
                lxc_list_init(&new->hooks[i]);
        lxc_list_init(&new->groups);
@@ -4364,6 +4365,17 @@ static void lxc_clear_saved_nics(struct lxc_conf *conf)
        free(conf->saved_nics);
 }
 
+static inline void lxc_clear_includes(struct lxc_conf *conf)
+{
+       struct lxc_list *it,*next;
+
+       lxc_list_for_each_safe(it, &conf->includes, next) {
+               lxc_list_del(it);
+               free(it->elem);
+               free(it);
+       }
+}
+
 void lxc_conf_free(struct lxc_conf *conf)
 {
        if (!conf)
@@ -4402,6 +4414,7 @@ void lxc_conf_free(struct lxc_conf *conf)
        lxc_clear_saved_nics(conf);
        lxc_clear_idmaps(conf);
        lxc_clear_groups(conf);
+       lxc_clear_includes(conf);
        free(conf);
 }
 

diff --git a/src/lxc/conf.h b/src/lxc/conf.h
index f5fab3d8420694ef4970269f156ed5559cfbc1e6..53590bc659a46436d141c9d804f7c6fe75906c83 100644 (file)
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -283,6 +283,7 @@ struct saved_nic {
 
 struct lxc_conf {
        int is_execute;
+       bool unexpanded;
        char *fstab;
        int tty;
        int pts;
@@ -338,6 +339,9 @@ struct lxc_conf {
 
        /* set to true when rootfs has been setup */
        bool rootfs_setup;
+
+       /* list of included files */
+       struct lxc_list includes;
 };
 
 int run_lxc_hooks(const char *name, char *hook, struct lxc_conf *conf,

diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index 70097f883239ad6778710bac3c601cde5dc32e09..2ab3fcb73a46ac547d9aa1fce394b6a625ce7d98 100644 (file)
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -1552,10 +1552,34 @@ static int config_console(const char *key, const char *value,
        return config_path_item(&lxc_conf->console.path, value);
 }
 
+static int add_include_file(const char *fname, struct lxc_conf *lxc_conf)
+{
+       struct lxc_list *list;
+       char *v;
+       int len = strlen(fname);
+
+       list = malloc(sizeof(*list));
+       if (!list)
+               return -1;
+       lxc_list_init(list);
+       v = malloc(len+1);
+       if (!v) {
+               free(list);
+               return -1;
+       }
+       strncpy(v, fname, len);
+       v[len] = '\0';
+       list->elem = v;
+       lxc_list_add_tail(&lxc_conf->includes, list);
+       return 0;
+}
+
 static int config_includefile(const char *key, const char *value,
                          struct lxc_conf *lxc_conf)
 {
-       return lxc_config_read(value, lxc_conf);
+       if (lxc_conf->unexpanded)
+               return add_include_file(value, lxc_conf);
+       return lxc_config_read(value, lxc_conf, NULL);
 }
 
 static int config_rootfs(const char *key, const char *value,
@@ -1673,8 +1697,10 @@ static int lxc_config_readline(char *buffer, struct lxc_conf *conf)
        return parse_line(buffer, conf);
 }
 
-int lxc_config_read(const char *file, struct lxc_conf *conf)
+int lxc_config_read(const char *file, struct lxc_conf *conf, struct lxc_conf *unexp_conf)
 {
+       int ret;
+
        if( access(file, R_OK) == -1 ) {
                return -1;
        }
@@ -1682,7 +1708,16 @@ int lxc_config_read(const char *file, struct lxc_conf *conf)
        if( ! conf->rcfile ) {
                conf->rcfile = strdup( file );
        }
-       return lxc_file_for_each_line(file, parse_line, conf);
+       ret = lxc_file_for_each_line(file, parse_line, conf);
+       if (ret)
+               return ret;
+       if (!unexp_conf)
+               return 0;
+       if (!unexp_conf->rcfile) {
+               unexp_conf->rcfile = strdup( file );
+       }
+
+       return lxc_file_for_each_line(file, parse_line, unexp_conf);
 }
 
 int lxc_config_define_add(struct lxc_list *defines, char* arg)
@@ -2223,6 +2258,10 @@ void write_config(FILE *fout, struct lxc_conf *c)
        struct lxc_list *it;
        int i;
 
+       lxc_list_for_each(it, &c->includes) {
+               fprintf(fout, "lxc.include = %s\n", (char *)it->elem);
+       }
+
        if (c->fstab)
                fprintf(fout, "lxc.mount = %s\n", c->fstab);
        lxc_list_for_each(it, &c->mount_list) {

diff --git a/src/lxc/confile.h b/src/lxc/confile.h
index 171614a91ed5e536ee83188b07eef49868c9195c..7e340898d27820057a9679b57912bb008f08e6b5 100644 (file)
--- a/src/lxc/confile.h
+++ b/src/lxc/confile.h
@@ -39,7 +39,7 @@ struct lxc_config_t {
 extern struct lxc_config_t *lxc_getconfig(const char *key);
 extern int lxc_list_nicconfigs(struct lxc_conf *c, const char *key, char *retv, int inlen);
 extern int lxc_listconfigs(char *retv, int inlen);
-extern int lxc_config_read(const char *file, struct lxc_conf *conf);
+extern int lxc_config_read(const char *file, struct lxc_conf *conf, struct lxc_conf *unexp_conf);
 
 extern int lxc_config_define_add(struct lxc_list *defines, char* arg);
 extern int lxc_config_define_load(struct lxc_list *defines,

diff --git a/src/lxc/lxc_execute.c b/src/lxc/lxc_execute.c
index 6949e2b84a27f423097313cfca8af751226b5555..b602793165de47ff7f39d2519c1c36c4e01b3697 100644 (file)
--- a/src/lxc/lxc_execute.c
+++ b/src/lxc/lxc_execute.c
@@ -131,7 +131,7 @@ int main(int argc, char *argv[])
                return 1;
        }
 
-       if (rcfile && lxc_config_read(rcfile, conf)) {
+       if (rcfile && lxc_config_read(rcfile, conf, NULL)) {
                ERROR("failed to read configuration file");
                return 1;
        }

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 5cedb27a71fb909c2d6cc1fe7e1a19e4836bed32..bb7b4bb4552578adc779708f8b84544458d00a40 100644 (file)
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -238,6 +238,10 @@ static void lxc_container_free(struct lxc_container *c)
                lxc_conf_free(c->lxc_conf);
                c->lxc_conf = NULL;
        }
+       if (c->lxc_unexp_conf) {
+               lxc_conf_free(c->lxc_unexp_conf);
+               c->lxc_unexp_conf = NULL;
+       }
        if (c->config_path) {
                free(c->config_path);
                c->config_path = NULL;
@@ -410,7 +414,14 @@ static bool load_config_locked(struct lxc_container *c, const char *fname)
 {
        if (!c->lxc_conf)
                c->lxc_conf = lxc_conf_init();
-       if (c->lxc_conf && !lxc_config_read(fname, c->lxc_conf))
+       if (!c->lxc_unexp_conf) {
+               c->lxc_unexp_conf = lxc_conf_init();
+               if (c->lxc_unexp_conf)
+                       c->lxc_unexp_conf->unexpanded = true;
+       }
+       if (c->lxc_conf && c->lxc_unexp_conf &&
+                       !lxc_config_read(fname, c->lxc_conf,
+                                        c->lxc_unexp_conf))
                return true;
        return false;
 }
@@ -1196,9 +1207,15 @@ out_error:
 
 static void lxcapi_clear_config(struct lxc_container *c)
 {
-       if (c && c->lxc_conf) {
-               lxc_conf_free(c->lxc_conf);
-               c->lxc_conf = NULL;
+       if (c) {
+               if (c->lxc_conf) {
+                       lxc_conf_free(c->lxc_conf);
+                       c->lxc_conf = NULL;
+               }
+               if (c->lxc_unexp_conf) {
+                       lxc_conf_free(c->lxc_unexp_conf);
+                       c->lxc_unexp_conf = NULL;
+               }
        }
 }
 
@@ -1321,6 +1338,7 @@ static bool lxcapi_create(struct lxc_container *c, const char *t,
        /* reload config to get the rootfs */
        lxc_conf_free(c->lxc_conf);
        c->lxc_conf = NULL;
+       c->lxc_unexp_conf = NULL;
        if (!load_config_locked(c, c->configfile))
                goto out_unlock;
 
@@ -1845,7 +1863,7 @@ static bool lxcapi_save_config(struct lxc_container *c, const char *alt_file)
        fout = fopen(alt_file, "w");
        if (!fout)
                goto out;
-       write_config(fout, c->lxc_conf);
+       write_config(fout, c->lxc_unexp_conf);
        fclose(fout);
        ret = true;
 
@@ -2072,11 +2090,17 @@ static bool set_config_item_locked(struct lxc_container *c, const char *key, con
 
        if (!c->lxc_conf)
                c->lxc_conf = lxc_conf_init();
-       if (!c->lxc_conf)
+       if (!c->lxc_unexp_conf) {
+               c->lxc_unexp_conf = lxc_conf_init();
+               c->lxc_unexp_conf->unexpanded = true;
+       }
+       if (!c->lxc_conf || !c->lxc_unexp_conf)
                return false;
        config = lxc_getconfig(key);
        if (!config)
                return false;
+       if (config->cb(key, v, c->lxc_unexp_conf) != 0)
+               return false;
        return (0 == config->cb(key, v, c->lxc_conf));
 }
 
@@ -2677,7 +2701,7 @@ static struct lxc_container *lxcapi_clone(struct lxc_container *c, const char *n
                SYSERROR("open %s", newpath);
                goto out;
        }
-       write_config(fout, c->lxc_conf);
+       write_config(fout, c->lxc_unexp_conf);
        fclose(fout);
        c->lxc_conf->rootfs.path = origroot;
 

diff --git a/src/lxc/lxccontainer.h b/src/lxc/lxccontainer.h
index 1d0628af8397e1ee716f5d3fde28f571236555f7..d1de399dd27155ff749329529741895e9eeada70 100644 (file)
--- a/src/lxc/lxccontainer.h
+++ b/src/lxc/lxccontainer.h
@@ -99,6 +99,16 @@ struct lxc_container {
         */
        struct lxc_conf *lxc_conf;
 
+       /*!
+        * \private
+        * The non-common, unexpanded configuration.  This includes the
+        * list of lxc.include files, and does not contain any
+        * individual configuration items from the include files.
+        * Anything coming from the container's own configuration file
+        * or from lxcapi_set_config_item() does get added here.
+        */
+       struct lxc_conf *lxc_unexp_conf;
+
        // public fields
        /*! Human-readable string representing last error */
        char *error_string;