MEDIUM: config: relax use_backend check to make the condition optional

Since it became possible to use log-format expressions in use_backend,
having a mandatory condition becomes annoying because configurations
are full of "if TRUE". Let's relax the check to accept no condition
like many other keywords (eg: redirect).
This commit is contained in:
Willy Tarreau 2014-04-23 01:21:56 +02:00
parent 74774c0f86
commit f51658dac4
4 changed files with 22 additions and 23 deletions

View File

@ -7705,8 +7705,7 @@ unique-id-header <name>
See also: "unique-id-format" See also: "unique-id-format"
use_backend <backend> if <condition> use_backend <backend> [{if | unless} <condition>]
use_backend <backend> unless <condition>
Switch to a specific backend if/unless an ACL-based condition is matched. Switch to a specific backend if/unless an ACL-based condition is matched.
May be used in sections : defaults | frontend | listen | backend May be used in sections : defaults | frontend | listen | backend
no | yes | yes | no no | yes | yes | no
@ -7714,7 +7713,8 @@ use_backend <backend> unless <condition>
<backend> is the name of a valid backend or "listen" section, or a <backend> is the name of a valid backend or "listen" section, or a
"log-format" string resolving to a backend name. "log-format" string resolving to a backend name.
<condition> is a condition composed of ACLs, as described in section 7. <condition> is a condition composed of ACLs, as described in section 7. If
it is omitted, the rule is unconditionally applied.
When doing content-switching, connections arrive on a frontend and are then When doing content-switching, connections arrive on a frontend and are then
dispatched to various backends depending on a number of conditions. The dispatched to various backends depending on a number of conditions. The

View File

@ -2866,22 +2866,17 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
goto out; goto out;
} }
if (strcmp(args[2], "if") != 0 && strcmp(args[2], "unless") != 0) { if (strcmp(args[2], "if") == 0 || strcmp(args[2], "unless") == 0) {
Alert("parsing [%s:%d] : '%s' requires either 'if' or 'unless' followed by a condition.\n", if ((cond = build_acl_cond(file, linenum, curproxy, (const char **)args + 2, &errmsg)) == NULL) {
file, linenum, args[0]); Alert("parsing [%s:%d] : error detected while parsing switching rule : %s.\n",
err_code |= ERR_ALERT | ERR_FATAL; file, linenum, errmsg);
goto out; err_code |= ERR_ALERT | ERR_FATAL;
} goto out;
}
if ((cond = build_acl_cond(file, linenum, curproxy, (const char **)args + 2, &errmsg)) == NULL) { err_code |= warnif_cond_conflicts(cond, SMP_VAL_FE_SET_BCK, file, linenum);
Alert("parsing [%s:%d] : error detected while parsing switching rule : %s.\n",
file, linenum, errmsg);
err_code |= ERR_ALERT | ERR_FATAL;
goto out;
} }
err_code |= warnif_cond_conflicts(cond, SMP_VAL_FE_SET_BCK, file, linenum);
rule = (struct switching_rule *)calloc(1, sizeof(*rule)); rule = (struct switching_rule *)calloc(1, sizeof(*rule));
rule->cond = cond; rule->cond = cond;
rule->be.name = strdup(args[1]); rule->be.name = strdup(args[1]);

View File

@ -1085,8 +1085,10 @@ void deinit(void)
list_for_each_entry_safe(rule, ruleb, &p->switching_rules, list) { list_for_each_entry_safe(rule, ruleb, &p->switching_rules, list) {
LIST_DEL(&rule->list); LIST_DEL(&rule->list);
prune_acl_cond(rule->cond); if (rule->cond) {
free(rule->cond); prune_acl_cond(rule->cond);
free(rule->cond);
}
free(rule); free(rule);
} }

View File

@ -1238,12 +1238,14 @@ static int process_switching_rules(struct session *s, struct channel *req, int a
struct switching_rule *rule; struct switching_rule *rule;
list_for_each_entry(rule, &s->fe->switching_rules, list) { list_for_each_entry(rule, &s->fe->switching_rules, list) {
int ret; int ret = 1;
ret = acl_exec_cond(rule->cond, s->fe, s, &s->txn, SMP_OPT_DIR_REQ|SMP_OPT_FINAL); if (rule->cond) {
ret = acl_pass(ret); ret = acl_exec_cond(rule->cond, s->fe, s, &s->txn, SMP_OPT_DIR_REQ|SMP_OPT_FINAL);
if (rule->cond->pol == ACL_COND_UNLESS) ret = acl_pass(ret);
ret = !ret; if (rule->cond->pol == ACL_COND_UNLESS)
ret = !ret;
}
if (ret) { if (ret) {
/* If the backend name is dynamic, try to resolve the name. /* If the backend name is dynamic, try to resolve the name.