MINOR: vars/cli: add a "get var" CLI command to retrieve global variables

Process-wide variables can now be displayed from the CLI using "get var"
followed by the variable name. They must all start with "proc." otherwise
they will not be found. The output is very similar to the one of the
debug converter, with a type and value being reported for the embedded
sample.

This command is limited to clients with the level "operator" or higher,
since it can possibly expose traffic-related data.

diff --git a/doc/management.txt b/doc/management.txt
index 80755be03eda390f65acc31f674ee2405c5f9df0..bd3622aa0600069f3495dae56bb15feccd2f994c 100644 (file)
--- a/doc/management.txt
+++ b/doc/management.txt
@@ -1770,6 +1770,12 @@ get acl <acl> <value>
 
      type="<type>":         The type of the returned sample.
 
+get var <name>
+  Show the existence, type and contents of the process-wide variable 'name'.
+  Only process-wide variables are readable, so the name must begin with
+  'proc.' otherwise no variable will be found. This command requires levels
+  "operator" or "admin".
+
 get weight <backend>/<server>
   Report the current weight and the initial weight of server <server> in
   backend <backend> or an error if either doesn't exist. The initial weight is

diff --git a/reg-tests/sample_fetches/vars.vtc b/reg-tests/sample_fetches/vars.vtc
index 14610688805ad8c507d59a3ca02c72eb53947724..b57156ce9d3532bf5d26679b1b59b2ee569560d4 100644 (file)
--- a/reg-tests/sample_fetches/vars.vtc
+++ b/reg-tests/sample_fetches/vars.vtc
@@ -26,6 +26,11 @@ haproxy h1 -conf {
        http-request return status 200 hdr x-var "proc=%[var(proc.int5)] sess=%[var(sess.int5)] req=%[var(req.int5)] str=%[var(proc.str)] uuid=%[var(proc.uuid)]"
 } -start
 
+haproxy h1 -cli {
+    send "get var proc.int5"
+    expect ~ "^proc.int5: type=sint value=<5>$"
+}
+
 client c1 -connect ${h1_fe1_sock} {
     txreq -req GET -url /req1_1
     rxresp
@@ -38,6 +43,11 @@ client c1 -connect ${h1_fe1_sock} {
     expect resp.http.x-var ~ "proc=10 sess=20 req=10 str=this is a string uuid=[0-9a-f]*-[0-9a-f]*-[0-9a-f]*-[0-9a-f]*-[0-9a-f]*"
 } -run
 
+haproxy h1 -cli {
+    send "get var proc.int5"
+    expect ~ "^proc.int5: type=sint value=<10>$"
+}
+
 client c2 -connect ${h1_fe1_sock} {
     txreq -req GET -url /req2_1
     rxresp
@@ -49,3 +59,8 @@ client c2 -connect ${h1_fe1_sock} {
     expect resp.status == 200
     expect resp.http.x-var ~ "proc=20 sess=40 req=20 str=this is a string uuid=[0-9a-f]*-[0-9a-f]*-[0-9a-f]*-[0-9a-f]*-[0-9a-f]*"
 } -run
+
+haproxy h1 -cli {
+    send "get var proc.int5"
+    expect ~ "^proc.int5: type=sint value=<20>$"
+}

diff --git a/src/vars.c b/src/vars.c
index 9be070b71f0b7a861c467949d64f90371e8c3361..11efd55a4a9bd3e4879e359f7363fb34d40d5dc4 100644 (file)
--- a/src/vars.c
+++ b/src/vars.c
@@ -2,8 +2,10 @@
 
 #include <haproxy/api.h>
 #include <haproxy/arg.h>
+#include <haproxy/buf.h>
 #include <haproxy/cfgparse.h>
 #include <haproxy/check.h>
+#include <haproxy/cli.h>
 #include <haproxy/global.h>
 #include <haproxy/http.h>
 #include <haproxy/http_rules.h>
@@ -867,6 +869,49 @@ static int vars_parse_global_set_var(char **args, int section_type, struct proxy
        return ret;
 }
 
+/* parse CLI's "get var <name>" */
+static int vars_parse_cli_get_var(char **args, char *payload, struct appctx *appctx, void *private)
+{
+       struct vars *vars;
+       struct sample smp;
+       int i;
+
+       if (!cli_has_level(appctx, ACCESS_LVL_OPER))
+               return 1;
+
+       if (!*args[2])
+               return cli_err(appctx, "Missing process-wide variable identifier.\n");
+
+       vars = get_vars(NULL, NULL, SCOPE_PROC);
+       if (!vars || vars->scope != SCOPE_PROC)
+               return 0;
+
+       if (!vars_get_by_name(args[2], strlen(args[2]), &smp))
+               return cli_err(appctx, "Variable not found.\n");
+
+       /* the sample returned by vars_get_by_name() is allocated into a trash
+        * chunk so we have no constraint to manipulate it.
+        */
+       chunk_printf(&trash, "%s: type=%s value=", args[2], smp_to_type[smp.data.type]);
+
+       if (!sample_casts[smp.data.type][SMP_T_STR] ||
+           !sample_casts[smp.data.type][SMP_T_STR](&smp)) {
+               chunk_appendf(&trash, "(undisplayable)");
+       } else {
+               /* Display the displayable chars*. */
+               b_putchr(&trash, '<');
+               for (i = 0; i < smp.data.u.str.data; i++) {
+                       if (isprint((unsigned char)smp.data.u.str.area[i]))
+                               b_putchr(&trash, smp.data.u.str.area[i]);
+                       else
+                               b_putchr(&trash, '.');
+               }
+               b_putchr(&trash, '>');
+               b_putchr(&trash, 0);
+       }
+       return cli_msg(appctx, LOG_INFO, trash.area);
+}
+
 static int vars_max_size(char **args, int section_type, struct proxy *curpx,
                          const struct proxy *defpx, const char *file, int line,
                          char **err, unsigned int *limit)
@@ -1016,3 +1061,11 @@ static struct cfg_kw_list cfg_kws = {{ },{
 }};
 
 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 },
+       { { NULL }, NULL, NULL, NULL }
+}};
+INITCALL1(STG_REGISTER, cli_register_kw, &cli_kws);