Expose cpu bugs and flags as info metrics. (#1788)

* Expose cpu bugs and flags as info metrics with a regexp filter.
* Automatically enable CPU info metrics when using flags or bugs feature.

Signed-off-by: domgoer <domdoumc@gmail.com>

4 files changed, 98 insertions, 2 deletions

diff --git a/collector/cpu_linux.go b/collector/cpu_linux.go
index dfa4d4a..65476d3 100644
--- a/collector/cpu_linux.go
+++ b/collector/cpu_linux.go
@@ -18,6 +18,7 @@ package collector
 import (
         "fmt"
         "path/filepath"
+        "regexp"
         "strconv"
         "sync"
 
@@ -32,16 +33,23 @@ type cpuCollector struct {
         fs                 procfs.FS
         cpu                *prometheus.Desc
         cpuInfo            *prometheus.Desc
+        cpuFlagsInfo       *prometheus.Desc
+        cpuBugsInfo        *prometheus.Desc
         cpuGuest           *prometheus.Desc
         cpuCoreThrottle    *prometheus.Desc
         cpuPackageThrottle *prometheus.Desc
         logger             log.Logger
         cpuStats           []procfs.CPUStat
         cpuStatsMutex      sync.Mutex
+
+        cpuFlagsIncludeRegexp *regexp.Regexp
+        cpuBugsIncludeRegexp  *regexp.Regexp
 }
 
 var (
         enableCPUInfo = kingpin.Flag("collector.cpu.info", "Enables metric cpu_info").Bool()
+        flagsInclude  = kingpin.Flag("collector.cpu.info.flags-include", "Filter the `flags` field in cpuInfo with a value that must be a regular expression").String()
+        bugsInclude   = kingpin.Flag("collector.cpu.info.bugs-include", "Filter the `bugs` field in cpuInfo with a value that must be a regular expression").String()
 )
 
 func init() {
@@ -54,7 +62,7 @@ func NewCPUCollector(logger log.Logger) (Collector, error) {
         if err != nil {
                 return nil, fmt.Errorf("failed to open procfs: %w", err)
         }
-        return &cpuCollector{
+        c := &cpuCollector{
                 fs:  fs,
                 cpu: nodeCPUSecondsDesc,
                 cpuInfo: prometheus.NewDesc(
@@ -62,6 +70,16 @@ func NewCPUCollector(logger log.Logger) (Collector, error) {
                         "CPU information from /proc/cpuinfo.",
                         []string{"package", "core", "cpu", "vendor", "family", "model", "model_name", "microcode", "stepping", "cachesize"}, nil,
                 ),
+                cpuFlagsInfo: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "flag_info"),
+                        "The `flags` field of CPU information from /proc/cpuinfo.",
+                        []string{"flag"}, nil,
+                ),
+                cpuBugsInfo: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "bug_info"),
+                        "The `bugs` field of CPU information from /proc/cpuinfo.",
+                        []string{"bug"}, nil,
+                ),
                 cpuGuest: prometheus.NewDesc(
                         prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "guest_seconds_total"),
                         "Seconds the cpus spent in guests (VMs) for each mode.",
@@ -78,7 +96,34 @@ func NewCPUCollector(logger log.Logger) (Collector, error) {
                         []string{"package"}, nil,
                 ),
                 logger: logger,
-        }, nil
+        }
+        err = c.compileIncludeFlags(flagsInclude, bugsInclude)
+        if err != nil {
+                return nil, fmt.Errorf("fail to compile --collector.cpu.info.flags-include and --collector.cpu.info.bugs-include, the values of them must be regular expressions: %w", err)
+        }
+        return c, nil
+}
+
+func (c *cpuCollector) compileIncludeFlags(flagsIncludeFlag, bugsIncludeFlag *string) error {
+        if (*flagsIncludeFlag != "" || *bugsIncludeFlag != "") && !*enableCPUInfo {
+                *enableCPUInfo = true
+                level.Info(c.logger).Log("msg", "--collector.cpu.info has been set to `true` because you set the following flags, like --collector.cpu.info.flags-include and --collector.cpu.info.bugs-include")
+        }
+
+        var err error
+        if *flagsIncludeFlag != "" {
+                c.cpuFlagsIncludeRegexp, err = regexp.Compile(*flagsIncludeFlag)
+                if err != nil {
+                        return err
+                }
+        }
+        if *bugsIncludeFlag != "" {
+                c.cpuBugsIncludeRegexp, err = regexp.Compile(*bugsIncludeFlag)
+                if err != nil {
+                        return err
+                }
+        }
+        return nil
 }
 
 // Update implements Collector and exposes cpu related metrics from /proc/stat and /sys/.../cpu/.
@@ -117,6 +162,31 @@ func (c *cpuCollector) updateInfo(ch chan<- prometheus.Metric) error {
                         cpu.Microcode,
                         cpu.Stepping,
                         cpu.CacheSize)
+
+                if err := updateFieldInfo(cpu.Flags, c.cpuFlagsIncludeRegexp, c.cpuFlagsInfo, ch); err != nil {
+                        return err
+                }
+                if err := updateFieldInfo(cpu.Bugs, c.cpuBugsIncludeRegexp, c.cpuBugsInfo, ch); err != nil {
+                        return err
+                }
+        }
+        return nil
+}
+
+func updateFieldInfo(valueList []string, filter *regexp.Regexp, desc *prometheus.Desc, ch chan<- prometheus.Metric) error {
+        if filter == nil {
+                return nil
+        }
+
+        for _, val := range valueList {
+                if !filter.MatchString(val) {
+                        continue
+                }
+                ch <- prometheus.MustNewConstMetric(desc,
+                        prometheus.GaugeValue,
+                        1,
+                        val,
+                )
         }
         return nil
 }
diff --git a/collector/fixtures/e2e-64k-page-output.txt b/collector/fixtures/e2e-64k-page-output.txt
index 7b857ff..cbed127 100644
--- a/collector/fixtures/e2e-64k-page-output.txt
+++ b/collector/fixtures/e2e-64k-page-output.txt
@@ -184,12 +184,24 @@ node_cooling_device_cur_state{name="0",type="Processor"} 0
 # HELP node_cooling_device_max_state Maximum throttle state of the cooling device
 # TYPE node_cooling_device_max_state gauge
 node_cooling_device_max_state{name="0",type="Processor"} 3
+# HELP node_cpu_bug_info The `bugs` field of CPU information from /proc/cpuinfo.
+# TYPE node_cpu_bug_info gauge
+node_cpu_bug_info{bug="cpu_meltdown"} 1
+node_cpu_bug_info{bug="mds"} 1
+node_cpu_bug_info{bug="spectre_v1"} 1
+node_cpu_bug_info{bug="spectre_v2"} 1
 # HELP node_cpu_core_throttles_total Number of times this cpu core has been throttled.
 # TYPE node_cpu_core_throttles_total counter
 node_cpu_core_throttles_total{core="0",package="0"} 5
 node_cpu_core_throttles_total{core="0",package="1"} 0
 node_cpu_core_throttles_total{core="1",package="0"} 0
 node_cpu_core_throttles_total{core="1",package="1"} 9
+# HELP node_cpu_flag_info The `flags` field of CPU information from /proc/cpuinfo.
+# TYPE node_cpu_flag_info gauge
+node_cpu_flag_info{flag="aes"} 1
+node_cpu_flag_info{flag="avx"} 1
+node_cpu_flag_info{flag="avx2"} 1
+node_cpu_flag_info{flag="constant_tsc"} 1
 # HELP node_cpu_guest_seconds_total Seconds the cpus spent in guests (VMs) for each mode.
 # TYPE node_cpu_guest_seconds_total counter
 node_cpu_guest_seconds_total{cpu="0",mode="nice"} 0.01
diff --git a/collector/fixtures/e2e-output.txt b/collector/fixtures/e2e-output.txt
index e8a5779..02ae152 100644
--- a/collector/fixtures/e2e-output.txt
+++ b/collector/fixtures/e2e-output.txt
@@ -232,12 +232,24 @@ node_cooling_device_cur_state{name="0",type="Processor"} 0
 # HELP node_cooling_device_max_state Maximum throttle state of the cooling device
 # TYPE node_cooling_device_max_state gauge
 node_cooling_device_max_state{name="0",type="Processor"} 3
+# HELP node_cpu_bug_info The `bugs` field of CPU information from /proc/cpuinfo.
+# TYPE node_cpu_bug_info gauge
+node_cpu_bug_info{bug="cpu_meltdown"} 1
+node_cpu_bug_info{bug="mds"} 1
+node_cpu_bug_info{bug="spectre_v1"} 1
+node_cpu_bug_info{bug="spectre_v2"} 1
 # HELP node_cpu_core_throttles_total Number of times this cpu core has been throttled.
 # TYPE node_cpu_core_throttles_total counter
 node_cpu_core_throttles_total{core="0",package="0"} 5
 node_cpu_core_throttles_total{core="0",package="1"} 0
 node_cpu_core_throttles_total{core="1",package="0"} 0
 node_cpu_core_throttles_total{core="1",package="1"} 9
+# HELP node_cpu_flag_info The `flags` field of CPU information from /proc/cpuinfo.
+# TYPE node_cpu_flag_info gauge
+node_cpu_flag_info{flag="aes"} 1
+node_cpu_flag_info{flag="avx"} 1
+node_cpu_flag_info{flag="avx2"} 1
+node_cpu_flag_info{flag="constant_tsc"} 1
 # HELP node_cpu_guest_seconds_total Seconds the cpus spent in guests (VMs) for each mode.
 # TYPE node_cpu_guest_seconds_total counter
 node_cpu_guest_seconds_total{cpu="0",mode="nice"} 0.01
diff --git a/end-to-end-test.sh b/end-to-end-test.sh
index 961dd27..955ab1d 100755
--- a/end-to-end-test.sh
+++ b/end-to-end-test.sh
@@ -107,6 +107,8 @@ fi
   --collector.qdisc.fixtures="collector/fixtures/qdisc/" \
   --collector.netclass.ignored-devices="(bond0|dmz|int)" \
   --collector.cpu.info \
+  --collector.cpu.info.flags-include="^(aes|avx.?|constant_tsc)$" \
+  --collector.cpu.info.bugs-include="^(cpu_meltdown|spectre_.*|mds)$" \
   --web.listen-address "127.0.0.1:${port}" \
   --log.level="debug" > "${tmpdir}/node_exporter.log" 2>&1 &