Use kingpin Strings in the generator cli for the mibs-dir

Signed-off-by: dnck <cookdj0128@gmail.com>

generator/README.md

@@ -35,14 +35,15 @@ by the snmp_exporter executable to collect data from the snmp enabled devices.
 
 Additional command are available for debugging, use the `help` command to see them.
 
-After building, you can pass a directory of mibs, a path to the `generator.yml`
+After building, you can pass a directories of mibs, a path to the `generator.yml`
 file and the intended path of your output file e.g. `snmp.yml` to the `generate`
 command like so,
 ```bash
 ./generator generate \
-  -m /tmp
+  -m /tmp/deviceFamilyMibs \
+  -m /tmp/sharedMibs \
   -g /tmp/generator.yml \
-  -o /tmp/snmp.yml \
+  -o /tmp/snmp.yml
 ```
 
 ### MIB Parsing options

generator/main.go

@@ -107,9 +107,9 @@ var (
 	failOnParseErrors  = kingpin.Flag("fail-on-parse-errors", "Exit with a non-zero status if there are MIB parsing errors").Default("false").Bool()
 	snmpMIBOpts        = kingpin.Flag("snmp.mibopts", "Toggle various defaults controlling MIB parsing, see snmpwalk --help").String()
 	generateCommand    = kingpin.Command("generate", "Generate snmp.yml from generator.yml")
-	userMibsDir        = generateCommand.Flag("mibs-dir", "Path to mibs directory").Default("").Short('m').String()
-	generatorYmlPath   = generateCommand.Flag("generator-path", "Path to the generator.yml file").Default("generator.yml").Short('g').String()
-	outputPath         = generateCommand.Flag("output-path", "Path to to write resulting config file").Default("snmp.yml").Short('o').String()
+	userMibsDir        = generateCommand.Flag("mibs-dir", "Paths to mibs directory").Default("").Short('m').Strings()
+	generatorYmlPath   = generateCommand.Flag("generator-path", "Path to the input generator.yml file").Default("generator.yml").Short('g').String()
+	outputPath         = generateCommand.Flag("output-path", "Path to write the snmp_exporter's config file").Default("snmp.yml").Short('o').String()
 	parseErrorsCommand = kingpin.Command("parse_errors", "Debug: Print the parse errors output by NetSNMP")
 	dumpCommand        = kingpin.Command("dump", "Debug: Dump the parsed and prepared MIBs")
 )

generator/net_snmp.go

@@ -71,6 +71,7 @@ import (
 	"io"
 	"os"
 	"sort"
+	"strings"
 
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
@@ -152,6 +153,15 @@ var (
 	}
 )
 
+// getMibsDir joins the user-specified MIB directories into a single string; if the user didn't pass any,
+// the default netsnmp mibs directory is returned.
+func getMibsDir(paths []string) string {
+	if len(paths) == 1 && paths[0] == "" {
+		return C.GoString(C.netsnmp_get_mib_directory())
+	}
+	return strings.Join(paths, ":")
+}
+
 // Initialize NetSNMP. Returns MIB parse errors.
 //
 // Warning: This function plays with the stderr file descriptor.
@@ -161,20 +171,9 @@ func initSNMP(logger log.Logger) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	if *userMibsDir != "" {
-		// The user told us where to load the mibs
-		err = level.Info(logger).Log("msg", "Loading MIBs", "from", *userMibsDir)
-		if err != nil {
-			return "", err
-		}
-		C.netsnmp_set_mib_directory(C.CString(*userMibsDir))
-	} else {
-		// Help the user find their MIB directories.
-		err = level.Info(logger).Log("msg", "Loading MIBs", "from", C.GoString(C.netsnmp_get_mib_directory()))
-		if err != nil {
-			return "", err
-		}
-	}
+	mibsDir := getMibsDir(*userMibsDir)
+	level.Info(logger).Log("msg", "Loading MIBs", "from", mibsDir)
+	C.netsnmp_set_mib_directory(C.CString(mibsDir))
 	if *snmpMIBOpts != "" {
 		C.snmp_mib_toggle_options(C.CString(*snmpMIBOpts))
 	}