From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Wed, 30 Sep 2026 13:39:56 +0000 (+0200)
Subject: MINOR: cli: implement wait be-unknown
X-Git-Tag: v3.5-dev9~5
X-Git-Url: https://git.kaiwu.me/$%7BISSUES%7D/static/gitweb.js?a=commitdiff_plain;h=0344260b9896e368966dd5fd2e1c97ca2a5fef0b;p=haproxy.git

MINOR: cli: implement wait be-unknown

Similar to srv-unknown, a new CLI wait condition "be-unknown" is added
to check if a name can be used for a new backend instance to create. A
failure is returned if a proxy already exists with this name, but it can
wait if this is a backend instance targeted for background deletion.
---

diff --git a/doc/management.txt b/doc/management.txt
index 607ee0270..b9826cbd0 100644
--- a/doc/management.txt
+++ b/doc/management.txt
@@ -4761,6 +4761,12 @@ wait { -h | <delay> } [<condition> [<args>...]]
     not met. If everything is OK before the delay, a success is returned and
     the operation is terminated.
 
+  - be-unknown <proxy> : this will wait for the specified backend name to be
+    available for a new instance to be created. This will fail if a proxy with
+    this name already exists, unless if this is a backend flagged for
+    background deletion, in which case a success will be returned if the
+    deletion is completed before the delay.
+
   - srv-removable <proxy>/<server> : this will wait for the specified server to
     be removable by the "del server" command, i.e. be in maintenance and no
     longer have any connection on it (neither active or idle). Some conditions
diff --git a/include/haproxy/cli-t.h b/include/haproxy/cli-t.h
index 42bc6ce09..331e3ede7 100644
--- a/include/haproxy/cli-t.h
+++ b/include/haproxy/cli-t.h
@@ -104,6 +104,7 @@ enum cli_wait_cond {
 	CLI_WAIT_COND_SRV_UNUSED,// wait for server to become unused
 	CLI_WAIT_COND_SRV_UNKNWN,// wait for server name to be available
 	CLI_WAIT_COND_BE_UNUSED, // wait for backend to become unused
+	CLI_WAIT_COND_BE_UNKNWN, // wait for backend name to be available
 };
 
 struct cli_wait_ctx {
diff --git a/src/cli.c b/src/cli.c
index 128643b4a..463d5193b 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -2473,6 +2473,9 @@ static int cli_parse_wait(char **args, char *payload, struct appctx *appctx, voi
 	else if (strcmp(args[2], "be-removable") == 0) {
 		ctx->cond = CLI_WAIT_COND_BE_UNUSED;
 	}
+	else if (strcmp(args[2], "be-unknown") == 0) {
+		ctx->cond = CLI_WAIT_COND_BE_UNKNWN;
+	}
 	else if (*args[2]) {
 		/* show the command's help either upon request (-h) or error */
 		err = "Usage: wait {-h|<duration>} [condition [args...]]\n"
@@ -2485,6 +2488,7 @@ static int cli_parse_wait(char **args, char *payload, struct appctx *appctx, voi
 			"    - srv-removable <px>/<sv> : wait for this server to become removable.\n"
 			"    - srv-unknown <px>/<sv> : wait for this server name to be available.\n"
 			"    - be-removable <px> : wait for this backend to become removable.\n"
+			"    - be-unknown <px> : wait for this backend name to become available.\n"
 			"";
 
 		if (strcmp(args[2], "-h") == 0)
@@ -2516,6 +2520,7 @@ static int cli_parse_wait(char **args, char *payload, struct appctx *appctx, voi
 	}
 
 	case CLI_WAIT_COND_BE_UNUSED:
+	case CLI_WAIT_COND_BE_UNKNWN:
 		if (!*args[3])
 			return cli_err(appctx, "Missing backend name.\n");
 		ctx->args[0] = strdup(args[3]);
@@ -2593,6 +2598,33 @@ static int cli_io_handler_wait(struct appctx *appctx)
 			return 1;
 		}
 	}
+	else if (ctx->cond == CLI_WAIT_COND_BE_UNKNWN) {
+		struct proxy *px;
+
+		if (proxy_find_by_name(ctx->args[0], PR_CAP_DEF, 0)) {
+			ctx->error = CLI_WAIT_ERR_FAIL;
+			ctx->msg = "Name already used by a default instance.\n";
+			return 1;
+		}
+
+		px = proxy_find_by_name(ctx->args[0], PR_CAP_NONE, 0);
+		if (!px) {
+			/* immediate success */
+			ctx->error = CLI_WAIT_ERR_DONE;
+			return 1;
+		}
+		else if (px->cap & PR_CAP_FE) {
+			ctx->error = CLI_WAIT_ERR_FAIL;
+			ctx->msg = "Name already used by a frontend/listen instance.\n";
+			return 1;
+		}
+		else if (!(px->flags & PR_FL_TO_PURGE)) {
+			/* unrecoverable failure */
+			ctx->error = CLI_WAIT_ERR_FAIL;
+			ctx->msg = "Backend not scheduled for purge.\n";
+			return 1;
+		}
+	}
 
 	/* and here we recalculate the new wait time or abort */
 	left  = tick_remain(now_ms, ctx->deadline);