MEDIUM: checks: Support expression to set the port

Since we have a session attached to tcp-check healthchecks, It is possible use
sample expression and variables. In addition, it is possible to add tcp-check
set-var rules to define custom variables. So, now, a sample expression can be
used to define the port to use to establish a connection for a tcp-check connect
rule. For instance:

    tcp-check set-var(check.port) int(8888)
    tcp-check connect port var(check.port)

diff --git a/doc/configuration.txt b/doc/configuration.txt
index ecd218bf0f4def82cbc6bf87e24b95761a5984f6..663f356b0532af3e75e9e021e858e3196609543c 100644 (file)
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -9821,10 +9821,10 @@ tcp-check connect [params*]
     default      Use default options of the server line to do the health
                  checks. This parameter is exclusive with all other options.
 
-    port         if not set, check port or server port is used.
+    port <expr>  if not set, check port or server port is used.
                  It tells HAProxy where to open the connection to.
                  <port> must be a valid TCP port source integer, from 1 to
-                 65535.
+                 65535 or an sample-fetch expression.
 
     addr <ip>    defines the IP address to do the health check.
 

diff --git a/include/types/checks.h b/include/types/checks.h
index 29d0ebd116e2ce4b685d751378d2147e80cdac52..49e4ed6c5c2de222d7e8180698575e3dd65476f8 100644 (file)
--- a/include/types/checks.h
+++ b/include/types/checks.h
@@ -225,6 +225,7 @@ struct tcpcheck_connect {
        int alpn_len;                  /* ALPN string length */
        uint16_t options;              /* options when setting up a new connection */
        uint16_t port;                 /* port to connect to */
+       struct sample_expr *port_expr; /* sample expr to determine the port, may be NULL */
        struct sockaddr_storage addr;  /* the address to the connect */
 };
 

diff --git a/src/checks.c b/src/checks.c
index cf6d0d3e36c0f26e46bc55cdc3235939b0c1d0f7..9e0edaf52e445448756df1afd6e418e73fc57fd8 100644 (file)
--- a/src/checks.c
+++ b/src/checks.c
@@ -64,6 +64,7 @@
 #include <proto/dns.h>
 #include <proto/proto_udp.h>
 #include <proto/ssl_sock.h>
+#include <proto/sample.h>
 
 static int httpchk_expect(struct server *s, int done);
 static int tcpcheck_get_step_id(struct check *, struct tcpcheck_rule *);
@@ -2870,6 +2871,15 @@ static enum tcpcheck_eval_ret tcpcheck_eval_connect(struct check *check, struct
        port = 0;
        if (!port && connect->port)
                port = connect->port;
+       if (!port && connect->port_expr) {
+               struct sample *smp;
+
+               smp = sample_fetch_as_type(check->proxy, check->sess, NULL,
+                                          SMP_OPT_DIR_REQ | SMP_OPT_FINAL,
+                                          connect->port_expr, SMP_T_SINT);
+               if (smp)
+                       port = smp->data.u.sint;
+       }
        if (!port && is_inet_addr(&connect->addr))
                port = get_host_port(&connect->addr);
        if (!port && check->port)
@@ -3465,6 +3475,7 @@ static void free_tcpcheck(struct tcpcheck_rule *rule, int in_pool)
        case TCPCHK_ACT_CONNECT:
                free(rule->connect.sni);
                free(rule->connect.alpn);
+               release_sample_expr(rule->connect.port_expr);
                break;
        case TCPCHK_ACT_COMMENT:
                break;
@@ -4084,11 +4095,12 @@ static struct tcpcheck_rule *parse_tcpcheck_action(char **args, int cur_arg, str
 }
 
 static struct tcpcheck_rule *parse_tcpcheck_connect(char **args, int cur_arg, struct proxy *px, struct list *rules,
-                                                   char **errmsg)
+                                                   const char *file, int line, char **errmsg)
 {
        struct tcpcheck_rule *chk = NULL;
        struct sockaddr_storage *sk = NULL;
        char *comment = NULL, *sni = NULL, *alpn = NULL;
+       struct sample_expr *port_expr = NULL;
        unsigned short conn_opts = 0;
        long port = 0;
        int alpn_len = 0;
@@ -4144,14 +4156,41 @@ static struct tcpcheck_rule *parse_tcpcheck_connect(char **args, int cur_arg, st
                        cur_arg++;
                }
                else if (strcmp(args[cur_arg], "port") == 0) {
+                       const char *p, *end;
+
                        if (!*(args[cur_arg+1])) {
-                               memprintf(errmsg, "'%s' expects a port number as argument.", args[cur_arg]);
+                               memprintf(errmsg, "'%s' expects a port number or a sample expression as argument.", args[cur_arg]);
                                goto error;
                        }
                        cur_arg++;
-                       port = atol(args[cur_arg]);
-                       if (port > 65535 || port < 1) {
-                               memprintf(errmsg, "expects a valid TCP port (from range 1 to 65535), got %s.", args[cur_arg]);
+
+                       port = 0;
+                       release_sample_expr(port_expr);
+                       p = args[cur_arg]; end = p + strlen(p);
+                       port = read_uint(&p, end);
+                       if (p != end) {
+                               int idx = 0;
+
+                               px->conf.args.ctx = ARGC_SRV;
+                               port_expr = sample_parse_expr((char *[]){args[cur_arg], NULL}, &idx,
+                                                             file, line, errmsg, &px->conf.args, NULL);
+
+                               if (!port_expr) {
+                                       memprintf(errmsg, "error detected while parsing port expression : %s", *errmsg);
+                                       goto error;
+                               }
+                               if (!(port_expr->fetch->val & SMP_VAL_BE_CHK_RUL)) {
+                                       memprintf(errmsg, "error detected while parsing port expression : "
+                                                 " fetch method '%s' extracts information from '%s', "
+                                                 "none of which is available here.\n",
+                                                 args[cur_arg], sample_src_names(port_expr->fetch->use));
+                                       goto error;
+                               }
+                               px->http_needed |= !!(port_expr->fetch->use & SMP_USE_HTTP_ANY);
+                       }
+                       else if (port > 65535 || port < 1) {
+                               memprintf(errmsg, "expects a valid TCP port (from range 1 to 65535) or a sample expression, got %s.",
+                                         args[cur_arg]);
                                goto error;
                        }
                }
@@ -4231,6 +4270,7 @@ static struct tcpcheck_rule *parse_tcpcheck_connect(char **args, int cur_arg, st
        chk->connect.sni     = sni;
        chk->connect.alpn    = alpn;
        chk->connect.alpn_len= alpn_len;
+       chk->connect.port_expr= port_expr;
        if (sk)
                chk->connect.addr = *sk;
        return chk;
@@ -4239,6 +4279,7 @@ static struct tcpcheck_rule *parse_tcpcheck_connect(char **args, int cur_arg, st
        free(alpn);
        free(sni);
        free(comment);
+       release_sample_expr(port_expr);
        return NULL;
 }
 
@@ -4535,7 +4576,7 @@ static int proxy_parse_tcpcheck(char **args, int section, struct proxy *curpx,
 
        cur_arg = 1;
        if (strcmp(args[cur_arg], "connect") == 0)
-               chk = parse_tcpcheck_connect(args, cur_arg, curpx, rules, errmsg);
+               chk = parse_tcpcheck_connect(args, cur_arg, curpx, rules, file, line, errmsg);
        else if (strcmp(args[cur_arg], "send") == 0 || strcmp(args[cur_arg], "send-binary") == 0)
                chk = parse_tcpcheck_send(args, cur_arg, rules, errmsg);
        else if (strcmp(args[cur_arg], "expect") == 0)