Add config.d-style directory for blahp configuration. HTCONDOR-521

The directory name is the name of the regular configuration file with
'.d' appended (default is /etc/blah.config.d/). Files in the directory
are processed in sorted order after the main configuration file. So
parameters set in config.d files will override those in the main file.

src/config.c

@@ -37,6 +37,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <regex.h>
+#include <dirent.h>
 
 #include "blahpd.h"
 #include "config.h"
@@ -89,8 +90,8 @@ config_setenv(const char *ipath)
   config_entry *cur;
   int n_added = 0;
 
-  envs_before = config_read_cmd(ipath, printenv_command_before, envs_before);
-  envs_after  = config_read_cmd(ipath, printenv_command_after, envs_after);
+  config_read_cmd(ipath, printenv_command_before, envs_before);
+  config_read_cmd(ipath, printenv_command_after, envs_after);
 
 
   /* Set in the local environment all env variables that were exported in */
@@ -117,9 +118,14 @@ config_read(const char *ipath)
   const char *set_command_format = ". %s; set";
   char *path;
   char *install_location=NULL;
+  char *config_dir=NULL;
   config_handle *rha;
   config_entry *bp;
   FILE *test;
+  int file_cnt;
+  struct dirent **file_list = NULL;
+  char full_file[PATH_MAX];
+  int i;
 
   if ((install_location = getenv("BLAHPD_LOCATION")) == NULL)
    {
@@ -163,6 +169,20 @@ config_read(const char *ipath)
     return NULL;
    }
 
+  config_dir = (char *)malloc(strlen(rha->config_path)+3);
+  sprintf(config_dir, "%s.d", rha->config_path);
+  file_cnt = scandir(config_dir, &file_list, NULL, alphasort);
+  for (i = 0; i < file_cnt; i++)
+   {
+    if (file_list[i]->d_name[0] != '.')
+	 {
+      snprintf(full_file, PATH_MAX, "%s/%s", config_dir, file_list[i]->d_name);
+      config_read_cmd(full_file, set_command_format, rha);
+     }
+    free(file_list[i]);
+   }
+  free(file_list);
+
   if ((bp = config_get("blah_bin_directory", rha)) != NULL)
    {
     rha->bin_path = strdup(bp->value);

src/scripts/blah.py

@@ -18,9 +18,14 @@ def __init__(self, path=None, defaults=None):
                 path = "/etc/blah.config"
         # RawConfigParser requires ini-style [section headers] but since
         # blah.config is also used as a shell script we need to fake one
+        config_dir = path + ".d/"
+        config_list = sorted(filter(os.path.isfile, glob.glob(config_dir + "*")))
+        config_list.insert(0, path)
         self.header = 'blahp'
-        with open(path) as f:
-            config = f.read()
+        config = "[%s]\n" % (self.header)
+        for file in config_list:
+            with open(file) as f:
+                config += f.read()
         vfile = StringIO('[%s]\n%s' % (self.header, config))
 
         super(BlahConfigParser, self).__init__(defaults=defaults)

src/scripts/blah_load_config.sh

@@ -48,12 +48,20 @@ fi
 
 # Let blah_bin_directory be overridden in the config file.
 
+config_file=/etc/blah.config
 if [ -r "$BLAHPD_CONFIG_LOCATION" ]; then
-  . $BLAHPD_CONFIG_LOCATION
+  config_file=$BLAHPD_CONFIG_LOCATION
+elif [ "x$BLAHPD_LOCATION" != "x" -a -r "${BLAHPD_LOCATION}/etc/blah.config" ]; then
+  config_file=${BLAHPD_LOCATION}/etc/blah.config
 elif [ -r "${GLITE_LOCATION:-/opt/glite}/etc/blah.config" ]; then
-  . ${GLITE_LOCATION:-/opt/glite}/etc/blah.config
-elif [ -r "${BLAHPD_LOCATION}/etc/blah.config" ]; then
-#   This will default to /etc/blah.config if BLAHPD_LOCATION is unset.
-  . ${BLAHPD_LOCATION}/etc/blah.config
+  config_file=${GLITE_LOCATION:-/opt/glite}/etc/blah.config
 fi
+config_dir=${config_file}.d
 
+. $config_file
+
+if [ -d "$config_dir" ] ; then
+  for file in `ls $config_dir` ; do
+    . ${config_dir}/${file}
+  done
+fi