Add cgroup summary collector

collector/cgroups_linux.go

@@ -0,0 +1,65 @@
+// Copyright 2022 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !nostat
+// +build !nostat
+
+package collector
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/go-kit/log"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/procfs"
+)
+
+type cgroupSummaryCollector struct {
+	fs      procfs.FS
+	cgroups *prometheus.Desc
+	logger  log.Logger
+}
+
+func init() {
+	registerCollector("cgroupSummary", defaultEnabled, NewCgroupSummaryCollector)
+}
+
+// NewCgroupSummaryCollector returns a new Collector exposing a summary of cgroups.
+func NewCgroupSummaryCollector(logger log.Logger) (Collector, error) {
+	fs, err := procfs.NewFS(*procPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open procfs: %w", err)
+	}
+	return &cgroupSummaryCollector{
+		fs: fs,
+		cgroups: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, "", "cgroups_total"),
+			"Current cgroup number of the subsystem.",
+			[]string{"subsys_name", "enabled"}, nil,
+		),
+		logger: logger,
+	}, nil
+}
+
+// Update implements Collector and exposes cgroup statistics.
+func (c *cgroupSummaryCollector) Update(ch chan<- prometheus.Metric) error {
+	cgroupSummarys, err := c.fs.CgroupSummarys()
+	if err != nil {
+		return err
+	}
+	for _, cs := range cgroupSummarys {
+		ch <- prometheus.MustNewConstMetric(c.cgroups, prometheus.CounterValue, float64(cs.Cgroups), cs.SubsysName, strconv.Itoa(cs.Enabled))
+	}
+	return nil
+}

collector/fixtures/e2e-output.txt

@@ -296,6 +296,20 @@ node_buddyinfo_blocks{node="0",size="8",zone="Normal"} 0
 node_buddyinfo_blocks{node="0",size="9",zone="DMA"} 1
 node_buddyinfo_blocks{node="0",size="9",zone="DMA32"} 0
 node_buddyinfo_blocks{node="0",size="9",zone="Normal"} 0
+# HELP node_cgroups_total Current cgroup number of the subsystem.
+# TYPE node_cgroups_total counter
+node_cgroups_total{enabled="1",subsys_name="blkio"} 170
+node_cgroups_total{enabled="1",subsys_name="cpu"} 172
+node_cgroups_total{enabled="1",subsys_name="cpuacct"} 172
+node_cgroups_total{enabled="1",subsys_name="cpuset"} 47
+node_cgroups_total{enabled="1",subsys_name="devices"} 170
+node_cgroups_total{enabled="1",subsys_name="freezer"} 47
+node_cgroups_total{enabled="1",subsys_name="hugetlb"} 47
+node_cgroups_total{enabled="1",subsys_name="memory"} 234
+node_cgroups_total{enabled="1",subsys_name="net_cls"} 47
+node_cgroups_total{enabled="1",subsys_name="perf_event"} 47
+node_cgroups_total{enabled="1",subsys_name="pids"} 170
+node_cgroups_total{enabled="1",subsys_name="rdma"} 1
 # HELP node_context_switches_total Total number of context switches.
 # TYPE node_context_switches_total counter
 node_context_switches_total 3.8014093e+07
@@ -3031,6 +3045,7 @@ node_scrape_collector_success{collector="bcache"} 1
 node_scrape_collector_success{collector="bonding"} 1
 node_scrape_collector_success{collector="btrfs"} 1
 node_scrape_collector_success{collector="buddyinfo"} 1
+node_scrape_collector_success{collector="cgroupSummary"} 1
 node_scrape_collector_success{collector="conntrack"} 1
 node_scrape_collector_success{collector="cpu"} 1
 node_scrape_collector_success{collector="cpufreq"} 1

collector/fixtures/proc/cgroups

@@ -0,0 +1,13 @@
+#subsys_name	hierarchy	num_cgroups	enabled
+cpuset	5	47	1
+cpu	3	172	1
+cpuacct	3	172	1
+blkio	6	170	1
+memory	7	234	1
+devices	11	170	1
+freezer	9	47	1
+net_cls	2	47	1
+perf_event	8	47	1
+hugetlb	12	47	1
+pids	10	170	1
+rdma	4	1	1

go.mod

@@ -18,7 +18,7 @@ require (
 	github.com/prometheus/client_model v0.2.0
 	github.com/prometheus/common v0.33.0
 	github.com/prometheus/exporter-toolkit v0.7.1
-	github.com/prometheus/procfs v0.7.4-0.20211011103944-1a7a2bd3279f
+	github.com/prometheus/procfs v0.7.4-0.20211209105546-0f8a320e1e1f
 	github.com/safchain/ethtool v0.2.0
 	github.com/siebenmann/go-kstat v0.0.0-20210513183136-173c9b0a9973 // indirect
 	github.com/soundcloud/go-runit v0.0.0-20150630195641-06ad41a06c4a

go.sum

@@ -236,8 +236,8 @@ github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsT
 github.com/prometheus/procfs v0.1.3/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
 github.com/prometheus/procfs v0.6.0/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
 github.com/prometheus/procfs v0.7.3/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
-github.com/prometheus/procfs v0.7.4-0.20211011103944-1a7a2bd3279f h1:ncXqc93eJV1Ncr3f6GA3MrIDNkNHvcPonRC2QgZaVkQ=
-github.com/prometheus/procfs v0.7.4-0.20211011103944-1a7a2bd3279f/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
+github.com/prometheus/procfs v0.7.4-0.20211209105546-0f8a320e1e1f h1:tg+5gOV1AkhTfWNi94UA5rvn+Mat/thyB2WASYAzPZo=
+github.com/prometheus/procfs v0.7.4-0.20211209105546-0f8a320e1e1f/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.6.1 h1:/FiVV8dS/e+YqF2JvO3yXRFbBLTIuSDkuC7aBOAvL+k=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=