From 21864e0ac4a790e4f9ab1a3af9e9ad01a661e751 Mon Sep 17 00:00:00 2001
From: Thomas Gruber <Thomas.Roehl@googlemail.com>
Date: Sat, 5 Mar 2022 14:42:04 +0100
Subject: [PATCH] Change default GpfsCollector command to `mmpmon` (#53)

* Set default cmd to 'mmpmon'

* Reuse looked up path

* Cast const to string
---
 collectors/gpfsMetric.go | 11 +++++++----
 collectors/gpfsMetric.md |  2 +-
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/collectors/gpfsMetric.go b/collectors/gpfsMetric.go
index adbc7fb..453704c 100644
--- a/collectors/gpfsMetric.go
+++ b/collectors/gpfsMetric.go
@@ -17,6 +17,8 @@ import (
 	lp "github.com/ClusterCockpit/cc-metric-collector/internal/ccMetric"
 )
 
+const DEFAULT_GPFS_CMD = `mmpmon`
+
 type GpfsCollector struct {
 	metricCollector
 	tags   map[string]string
@@ -38,7 +40,7 @@ func (m *GpfsCollector) Init(config json.RawMessage) error {
 	m.setup()
 
 	// Set default mmpmon binary
-	m.config.Mmpmon = "/usr/lpp/mmfs/bin/mmpmon"
+	m.config.Mmpmon = string(DEFAULT_GPFS_CMD)
 
 	// Read JSON configuration
 	if len(config) > 0 {
@@ -64,17 +66,18 @@ func (m *GpfsCollector) Init(config json.RawMessage) error {
 	// GPFS / IBM Spectrum Scale file system statistics can only be queried by user root
 	user, err := user.Current()
 	if err != nil {
-		return fmt.Errorf("Failed to get current user: %v", err)
+		return fmt.Errorf("failed to get current user: %v", err)
 	}
 	if user.Uid != "0" {
 		return fmt.Errorf("GPFS file system statistics can only be queried by user root")
 	}
 
 	// Check if mmpmon is in executable search path
-	_, err = exec.LookPath(m.config.Mmpmon)
+	p, err := exec.LookPath(m.config.Mmpmon)
 	if err != nil {
-		return fmt.Errorf("Failed to find mmpmon binary '%s': %v", m.config.Mmpmon, err)
+		return fmt.Errorf("failed to find mmpmon binary '%s': %v", m.config.Mmpmon, err)
 	}
+	m.config.Mmpmon = p
 
 	m.init = true
 	return nil
diff --git a/collectors/gpfsMetric.md b/collectors/gpfsMetric.md
index 4a6a058..4f2c897 100644
--- a/collectors/gpfsMetric.md
+++ b/collectors/gpfsMetric.md
@@ -16,7 +16,7 @@ The reported filesystems can be filtered with the `exclude_filesystem` option
 in the configuration.
 
 The path to the `mmpmon` command can be configured with the `mmpmon_path` option
-in the configuration.
+in the configuration. If nothing is set, the collector searches in `$PATH` for `mmpmon`.
 
 Metrics:
 * `bytes_read`