MINOR: cfgparse-global: add more checks for "chroot" argument

If directory provided as a "chroot" keyword argument does not exist or
inaccessible, this is reported only at the latest initialization stage, when
haproxy tries to perform chroot. Sometimes it's not very convenient, as the
process is already bound to listen sockets.

This was done explicitly in order not to break the case, when haproxy is
launched with "-c" option in some specific environment, where it's not possible
to create or to modify chroot directory, provided in the configuration.

So, let's add more checks for "chroot" directory during the parsing
stage and let's show diagnostic warnings, if this directory has become
non-accesible or was deleted. Like this, users, who wants to catch errors
related to misconfigured chroot before starting the process, can launch haproxy
with -dW and -dD. zero-warning mode will stop the process with error, if any
warning was emitted during initialization stage.

diff --git a/src/cfgparse-global.c b/src/cfgparse-global.c
index 45f06ab0393a4b56299e46c68c62f2271776b0aa..c604d672794ff10adffc2082c857493fcc82caa6 100644 (file)
--- a/src/cfgparse-global.c
+++ b/src/cfgparse-global.c
@@ -1607,6 +1607,8 @@ static int cfg_parse_global_chroot(char **args, int section_type, struct proxy *
                                   const struct proxy *defpx, const char *file, int line,
                                   char **err)
 {
+       struct stat dir_stat;
+
        if (too_many_args(1, args, err, NULL))
                return -1;
 
@@ -1620,6 +1622,25 @@ static int cfg_parse_global_chroot(char **args, int section_type, struct proxy *
        }
        global.chroot = strdup(args[1]);
 
+       /* some additional test for chroot dir, warn messages might be
+        * handy to catch misconfiguration errors more quickly
+        */
+       if (stat(args[1], &dir_stat) != 0) {
+               if (errno == ENOENT)
+                       ha_diag_warning("parsing [%s:%d]: '%s': '%s': %s.\n",
+                                       file, line, args[0], args[1], strerror(errno));
+               else if (errno == EACCES)
+                       ha_diag_warning("parsing [%s:%d]: '%s': '%s': %s "
+                                       "(process is need to be started with root priviledges to be able to chroot).\n",
+                                       file, line, args[0], args[1], strerror(errno));
+               else
+                       ha_diag_warning("parsing [%s:%d]: '%s': '%s': stat() is failed: %s.\n",
+                                       file, line, args[0], args[1], strerror(errno));
+       } else if ((dir_stat.st_mode & S_IFMT) != S_IFDIR) {
+               ha_diag_warning("parsing [%s:%d]: '%s': '%s' is not a directory.\n",
+                               file, line, args[0], args[1]);
+       }
+
        return 0;
 }