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MEDIUM: vars: also support format strings in CLI's "set var" command

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Most often "set var" on the CLI is used to set a string, and using only
expressions is not always convenient, particularly when trying to
concatenate variables sur as host names and paths.

Now the "set var" command supports an optional keyword before the value
to indicate its type. "expr" takes an expression just like before this
patch, and "fmt" a format string, making it work like the "set-var-fmt"
actions.

The VTC was updated to include a test on the format string.
This commit is contained in:
Willy Tarreau 2021-09-03 09:47:37 +02:00
parent 753d4db5f3
commit e93bff4107
3 changed files with 57 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
doc/management.txt
View File

@ -2254,15 +2254,18 @@ set timeout cli <delay>
some indicators without being disconnected. The delay is passed in seconds.
set var <name> <expression>
set var <name> expr <expression>
set var <name> fmt <format>
Allows to set or overwrite the process-wide variable 'name' with the result
of expression <expression>. Only process-wide variables may be used, so the
name must begin with 'proc.' otherwise no variable will be set. The
<expression> may only involve "internal" sample fetch keywords and converters
even though the most likely useful ones will be str('something') or int().
Note that the command line parser doesn't know about quotes, so any space in
the expression must be preceded by a backslash. This command requires levels
"operator" or "admin". This command is only supported on a CLI connection
running in experimental mode (see "experimental-mode on").
of expression <expression> or format string <format>. Only process-wide
variables may be used, so the name must begin with 'proc.' otherwise no
variable will be set. The <expression> and <format> may only involve
"internal" sample fetch keywords and converters even though the most likely
useful ones will be str('something'), int(), simple strings or references to
other variables. Note that the command line parser doesn't know about quotes,
so any space in the expression must be preceded by a backslash. This command
requires levels "operator" or "admin". This command is only supported on a
CLI connection running in experimental mode (see "experimental-mode on").
set weight <backend>/<server> <weight>[%]
Change a server's weight to the value passed in argument. If the value ends

2
reg-tests/sample_fetches/vars.vtc
View File

@ -71,7 +71,7 @@ haproxy h1 -cli {
}
haproxy h1 -cli {
send "experimental-mode on; set var proc.str str(updated)"
send "experimental-mode on; set var proc.str str(updating); set var proc.str fmt %[var(proc.str),regsub(ing,ed)]"
expect ~ .*
}

58
src/vars.c
View File

@ -1015,7 +1015,11 @@ static int vars_parse_cli_get_var(char **args, char *payload, struct appctx *app
return cli_msg(appctx, LOG_INFO, trash.area);
}
/* parse CLI's "set var <name> <expression>" */
/* parse CLI's "set var <name>". It accepts:
* - set var <name> <expression>
* - set var <name> expr <expression>
* - set var <name> fmt <format>
*/
static int vars_parse_cli_set_var(char **args, char *payload, struct appctx *appctx, void *private)
{
struct proxy px = {
@ -1027,31 +1031,50 @@ static int vars_parse_cli_set_var(char **args, char *payload, struct appctx *app
.arg.vars.scope = SCOPE_PROC,
.from = ACT_F_CLI_PARSER,
};
enum obj_type objt = OBJ_TYPE_NONE;
struct session *sess = NULL;
enum act_parse_ret p_ret;
char *old_arg2;
char *tmp_arg2;
const char *tmp_args[3];
int tmp_arg;
char *tmp_act;
char *err = NULL;
int arg = 2; // variable name
int nberr;
int use_fmt = 0;
LIST_INIT(&px.conf.args.list);
if (!cli_has_level(appctx, ACCESS_LVL_OPER))
return 1;
if (!*args[2] || !*args[3])
return cli_err(appctx, "Missing process-wide variable identifier and expression.\n");
if (!*args[2])
return cli_err(appctx, "Missing process-wide variable identifier.\n");
tmp_arg2 = NULL;
if (!memprintf(&tmp_arg2, "set-var(%s)", args[2])) {
if (!*args[3])
return cli_err(appctx, "Missing either 'expr', 'fmt' or expression.\n");
if (*args[4]) {
/* this is the long format */
if (strcmp(args[3], "fmt") == 0)
use_fmt = 1;
else if (strcmp(args[3], "expr") != 0) {
memprintf(&err, "'%s %s': arg type must be either 'expr' or 'fmt' but got '%s'.", args[0], args[1], args[3]);
goto fail;
}
}
tmp_act = NULL;
if (!memprintf(&tmp_act, "set-var%s(%s)", use_fmt ? "-fmt" : "", args[2])) {
memprintf(&err, "memory allocation error.");
goto fail;
}
/* parse_store() will always return a message in <err> on error */
old_arg2 = args[2]; args[2] = tmp_arg2;
p_ret = parse_store((const char **)(args + 1), &arg, &px, &rule, &err);
free(args[2]); args[2] = old_arg2;
tmp_args[0] = tmp_act;
tmp_args[1] = (*args[4]) ? args[4] : args[3];
tmp_args[2] = "";
tmp_arg = 1; // must point to the first arg after the action
p_ret = parse_store(tmp_args, &tmp_arg, &px, &rule, &err);
free(tmp_act);
if (p_ret != ACT_RET_PRS_OK)
goto fail;
@ -1069,8 +1092,17 @@ static int vars_parse_cli_set_var(char **args, char *payload, struct appctx *app
goto fail;
}
action_store(&rule, &px, NULL, NULL, 0);
if (use_fmt && !(sess = session_new(&px, NULL, &objt))) {
release_sample_expr(rule.arg.vars.expr);
memprintf(&err, "memory allocation error.");
goto fail;
}
action_store(&rule, &px, sess, NULL, 0);
release_sample_expr(rule.arg.vars.expr);
if (sess)
session_free(sess);
appctx->st0 = CLI_ST_PROMPT;
return 0;
fail:
@ -1239,7 +1271,7 @@ INITCALL1(STG_REGISTER, cfg_register_keywords, &cfg_kws);
/* register cli keywords */
static struct cli_kw_list cli_kws = {{ },{
{ { "get", "var", NULL }, "get var <name> : retrieve contents of a process-wide variable", vars_parse_cli_get_var, NULL },
{ { "set", "var", NULL }, "set var <name> <expr> : set variable from an expression", vars_parse_cli_set_var, NULL, NULL, NULL, ACCESS_EXPERIMENTAL },
{ { "set", "var", NULL }, "set var <name> [fmt|expr] {<fmt>|<expr>}: set variable from an expression or a format", vars_parse_cli_set_var, NULL, NULL, NULL, ACCESS_EXPERIMENTAL },
{ { NULL }, NULL, NULL, NULL }
}};
INITCALL1(STG_REGISTER, cli_register_kw, &cli_kws);