Add DNSDBQ_CONFIG_FILE environment variable which can specify a diffe…

…rent configuration file to use (#6)

* Add DNSDBQ_CONFIG_FILE environment variable which can specify a different configuration file to use.

dnsdbflex.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2020 by Farsight Security, Inc.
+ * Copyright (c) 2014-2021 by Farsight Security, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -446,23 +446,23 @@ help(void) {
 	printf("usage: %s [-cdFhjqsTUv46] \n",
 	       program_name);
 #if 0 /* disable output limit feature */
-	puts("\t[-l QUERY-LIMIT] [-L OUTPUT-LIMIT] [-A after] [-B before]\n"
+	puts("\t[-l QUERY-LIMIT] [-L OUTPUT-LIMIT] [-A AFTER] [-B BEFORE]\n"
 #else
-	puts("\t[-l QUERY-LIMIT] [-A after] [-B before]\n"
+	puts("\t[-l QUERY-LIMIT] [-A AFTER] [-B BEFORE]\n"
 #endif
-	     "\t[-u system] [-O offset]\n"
+	     "\t[-u SYSTEM] [-O OFFSET]\n"
 	     "\t{\n"
-	     "\t\t[--regex regex] |\n"
-	     "\t\t[--glob glob]\n"
+	     "\t\t[--regex REGEX] |\n"
+	     "\t\t[--glob GLOB]\n"
 	     "\t}\n"
-	     "\t[--exclude glob|regex]\n"
+	     "\t[--exclude GLOB|REGEX]\n"
 #ifdef DETAILS_SUPPORTED
 	     "\t[--mode terse|t|details|d]\n"
 #else
 	     "\t[--mode terse|t]\n"
 #endif
 	     "\t[-s rrnames|n|rdata|d]\n"
-	     "\t[-t rrtype]\n"
+	     "\t[-t RRTYPE]\n"
 	     "for -A and -B, use absolute format YYYY-MM-DD[ HH:MM:SS],\n"
 	     "\tor relative format %dw%dd%dh%dm%ds.\n"
 	     "use -c to get complete (strict) time matching for -A and -B.\n"
@@ -589,21 +589,34 @@ parse_long(const char *in, long *out) {
  */
 static void
 read_configs(void) {
+	char *value;
 	const char * const *conf;
 	char *cf = NULL;
 
-	for (conf = conf_files; *conf != NULL; conf++) {
-		wordexp_t we;
-
-		wordexp(*conf, &we, WRDE_NOCMD);
-		cf = strdup(we.we_wordv[0]);
-		assert(cf != NULL);
-		wordfree(&we);
-		if (access(cf, R_OK) == 0) {
-			DEBUG(1, true, "conf found: '%s'\n", cf);
-			break;
+	value = getenv(env_config_file);
+	if (value != NULL) {
+		if (access(value, R_OK) == 0) {
+			DEBUG(1, true, "conf found via env variable: '%s'\n", value);
+			cf = strdup(value);
+		} else {
+			fprintf(stderr, "%s: Cannot read configuration file '%s' named in env variable: %s\n",
+				program_name, value, strerror(errno));
+			my_exit(1);
+		}
+	} else {
+		for (conf = conf_files; *conf != NULL; conf++) {
+			wordexp_t we;
+
+			wordexp(*conf, &we, WRDE_NOCMD);
+			cf = strdup(we.we_wordv[0]);
+			assert(cf != NULL);
+			wordfree(&we);
+			if (access(cf, R_OK) == 0) {
+				DEBUG(1, true, "conf found: '%s'\n", cf);
+				break;
+			}
+			DESTROY(cf);
 		}
-		DESTROY(cf);
 	}
 	if (cf != NULL) {
 		char *cmd, *line;

dnsdbflex.man

@@ -316,10 +316,24 @@ $ dnsdbflex... -B 2013-01-22
 .Ic ~/.dnsdb-query.conf
 or
 .Ic /etc/dnsdb-query.conf :
-configuration file which should contain:
+configuration file which can specify the API key, etc. variables. The
+first of these which is readable will be used, alone, in its
+entirety.  See the
+.Ic DNSDBQ_CONFIG_FILE
+environment variable which can specify a different configuration
+file to use.
+.Pp
+For backwards compability,
+.Ic ~/.isc-dnsdb-query.conf
+and
+.Ic /etc/isc-dnsdb-query.conf
+are also valid, but deprecated.
+.Pp
+The variables which can be set in the configuration file are as
+follows:
 .Bl -tag -width ".Ev DNSDB_API_KEY , APIKEY"
-.It Ev APIKEY
-contains the user's API key (no default).
+.It Ev DNSDB_API_KEY , APIKEY
+contains the user's DNSDB apikey (no default).
 .It Ev DNSDB_SERVER
 contains the URL of the DNSDB API server (default is <\fI\%https://api.dnsdb.info\fP>),
 and optionally the URI prefix for the database.
@@ -330,19 +344,15 @@ option described above. Can only be "dnsdb2". If unset,
 .Nm dnsdbflex
 will probe for any configured system.
 .El
-.Pp
-For backwards compability,
-.Ic ~/.isc-dnsdb-query.conf
-and
-.Ic /etc/isc-dnsdb-query.conf
-are also valid, but deprecated.
 .Sh ENVIRONMENT
 The following environment variables affect the execution of
 .Nm :
-.Bl -tag -width ".Ev DNSDB_API_KEY , APIKEY"
-.It Ev DNSDB_API_KEY , APIKEY
-contains the user's API key. If DNSDB_API_KEY is not present, then APIKEY will
-be used. If neither variable is present, the configuration file is consulted.
+.Bl -tag -width ".Ev DNSDBQ_CONFIG_FILE"
+.It Ev DNSDBQ_CONFIG_FILE
+specifies the configuration file to use, overriding the internal search list.
+.It Ev DNSDB_API_KEY
+contains the user's apikey. The older APIKEY environment variable has
+been retired, though it can still be used in the configuration file.
 .It Ev DNSDB_SERVER
 contains the URL of the DNSDB API server, and optionally a URI prefix to be
 used. If not set, the configuration file is consulted.

globals.h

@@ -26,9 +26,10 @@
 #endif
 
 EXTERN	const char id_swclient[]	INIT("dnsdbflex");
-EXTERN	const char id_version[]		INIT("1.0.5");
+EXTERN	const char id_version[]		INIT("1.0.6");
 EXTERN	const char *program_name	INIT(NULL);
 EXTERN	const char jsonl_header[]	INIT("Accept: application/x-ndjson");
+EXTERN	const char env_config_file[]	INIT("DNSDBQ_CONFIG_FILE");
 EXTERN	const char status_noerror[]	INIT("NOERROR");
 EXTERN	const char status_error[]	INIT("ERROR");
 EXTERN	pdns_system_ct psys		INIT(NULL);