nbd-proxy: allow default configurations
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/nbd-proxy.c b/nbd-proxy.c
index cb3c33c..e251a1e 100644
--- a/nbd-proxy.c
+++ b/nbd-proxy.c
@@ -40,6 +40,7 @@
struct config {
char *name;
+ bool is_default;
char *nbd_device;
struct json_object *metadata;
};
@@ -56,6 +57,7 @@
size_t bufsize;
struct config *configs;
int n_configs;
+ struct config *default_config;
};
static const char *conf_path = SYSCONFDIR "/nbd-proxy/config.json";
@@ -414,6 +416,9 @@
config->nbd_device = strdup(json_object_get_string(tmp));
config->name = strdup(name);
+ jrc = json_object_object_get_ex(obj, "default", &tmp);
+ config->is_default = jrc && json_object_get_boolean(tmp);
+
jrc = json_object_object_get_ex(obj, "metadata", &meta);
if (jrc && json_object_is_type(meta, json_type_object))
config->metadata = json_object_get(meta);
@@ -476,15 +481,28 @@
ctx->configs = calloc(ctx->n_configs, sizeof(*ctx->configs));
i = 0;
- json_object_object_foreach(tmp, name, config) {
- rc = config_parse_one(&ctx->configs[i], name, config);
+ json_object_object_foreach(tmp, name, config_json) {
+ struct config *config = &ctx->configs[i];
+
+ rc = config_parse_one(config, name, config_json);
if (rc)
goto err_free;
+
+ if (config->is_default) {
+ if (ctx->default_config) {
+ warn("multiple configs flagged as default");
+ goto err_free;
+ }
+ ctx->default_config = config;
+ }
i++;
}
json_object_put(obj);
+ if (ctx->n_configs == 1)
+ ctx->default_config = &ctx->configs[0];
+
return 0;
err_free:
@@ -500,17 +518,27 @@
config = NULL;
- /* find a matching config... */
- for (i = 0; i < ctx->n_configs; i++) {
- if (!strcmp(ctx->configs[i].name, name)) {
- config = &ctx->configs[i];
- break;
+ if (!name) {
+ /* no config specified: use the default */
+ if (!ctx->default_config) {
+ warnx("no config specified, and no default");
+ return -1;
}
- }
+ config = ctx->default_config;
- if (!config) {
- warnx("no such configuration '%s'", name);
- return -1;
+ } else {
+ /* find a matching config... */
+ for (i = 0; i < ctx->n_configs; i++) {
+ if (!strcmp(ctx->configs[i].name, name)) {
+ config = &ctx->configs[i];
+ break;
+ }
+ }
+
+ if (!config) {
+ warnx("no such configuration '%s'", name);
+ return -1;
+ }
}
/* ... and apply it */
@@ -524,12 +552,10 @@
struct ctx _ctx, *ctx;
int rc;
- if (argc != 2) {
- fprintf(stderr, "usage: %s <configuration>\n", argv[0]);
- return EXIT_FAILURE;
- }
+ config_name = NULL;
- config_name = argv[1];
+ if (argc > 1)
+ config_name = argv[1];
ctx = &_ctx;
memset(ctx, 0, sizeof(*ctx));