Add process_maximum_virtual_memory_bytes metric

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

prometheus/process_collector.go

@@ -20,7 +20,8 @@ type processCollector struct {
 	pidFn           func() (int, error)
 	cpuTotal        *Desc
 	openFDs, maxFDs *Desc
-	vsize, rss      *Desc
+	vsize, maxVsize *Desc
+	rss             *Desc
 	startTime       *Desc
 }
 
@@ -72,6 +73,11 @@ func NewProcessCollectorPIDFn(
 			"Virtual memory size in bytes.",
 			nil, nil,
 		),
+		maxVsize: NewDesc(
+			ns+"process_max_virtual_memory_bytes",
+			"Maximum amount of virtual memory available in bytes.",
+			nil, nil,
+		),
 		rss: NewDesc(
 			ns+"process_resident_memory_bytes",
 			"Resident memory size in bytes.",
@@ -98,6 +104,7 @@ func (c *processCollector) Describe(ch chan<- *Desc) {
 	ch <- c.openFDs
 	ch <- c.maxFDs
 	ch <- c.vsize
+	ch <- c.maxVsize
 	ch <- c.rss
 	ch <- c.startTime
 }
@@ -135,5 +142,6 @@ func (c *processCollector) processCollect(ch chan<- Metric) {
 
 	if limits, err := p.NewLimits(); err == nil {
 		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
+		ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
 	}
 }

prometheus/process_collector_test.go

@@ -43,12 +43,14 @@ func TestProcessCollector(t *testing.T) {
 		regexp.MustCompile("\nprocess_cpu_seconds_total [0-9]"),
 		regexp.MustCompile("\nprocess_max_fds [1-9]"),
 		regexp.MustCompile("\nprocess_open_fds [1-9]"),
+		regexp.MustCompile("\nprocess_max_virtual_memory_bytes (-1|[1-9])"),
 		regexp.MustCompile("\nprocess_virtual_memory_bytes [1-9]"),
 		regexp.MustCompile("\nprocess_resident_memory_bytes [1-9]"),
 		regexp.MustCompile("\nprocess_start_time_seconds [0-9.]{10,}"),
 		regexp.MustCompile("\nfoobar_process_cpu_seconds_total [0-9]"),
 		regexp.MustCompile("\nfoobar_process_max_fds [1-9]"),
 		regexp.MustCompile("\nfoobar_process_open_fds [1-9]"),
+		regexp.MustCompile("\nfoobar_process_max_virtual_memory_bytes (-1|[1-9])"),
 		regexp.MustCompile("\nfoobar_process_virtual_memory_bytes [1-9]"),
 		regexp.MustCompile("\nfoobar_process_resident_memory_bytes [1-9]"),
 		regexp.MustCompile("\nfoobar_process_start_time_seconds [0-9.]{10,}"),