Comment more packages to pass go lint

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

metrics/cgroups/cgroups.go

@@ -15,6 +15,7 @@ import (
 	"golang.org/x/net/context"
 )
 
+// Config for the cgroups monitor
 type Config struct {
 	NoPrometheus bool `toml:"no_prometheus"`
 }
@@ -28,14 +29,15 @@ func init() {
 	})
 }
 
+// New returns a new cgroups monitor
 func New(ic *plugin.InitContext) (interface{}, error) {
 	var ns *metrics.Namespace
 	config := ic.Config.(*Config)
 	if !config.NoPrometheus {
 		ns = metrics.NewNamespace("container", "", nil)
 	}
-	collector := NewCollector(ns)
-	oom, err := NewOOMCollector(ns)
+	collector := newCollector(ns)
+	oom, err := newOOMCollector(ns)
 	if err != nil {
 		return nil, err
 	}
@@ -51,8 +53,8 @@ func New(ic *plugin.InitContext) (interface{}, error) {
 }
 
 type cgroupsMonitor struct {
-	collector *Collector
-	oom       *OOMCollector
+	collector *collector
+	oom       *oomCollector
 	context   context.Context
 	publisher events.Publisher
 }

metrics/cgroups/metrics.go

@@ -14,22 +14,24 @@ import (
 )
 
 var (
+	// ErrAlreadyCollected is returned when a cgroups is already being monitored
 	ErrAlreadyCollected = errors.New("cgroup is already being collected")
-	ErrCgroupNotExists  = errors.New("cgroup does not exist in the collector")
+	// ErrCgroupNotExists is returns when a cgroup no longer exists
+	ErrCgroupNotExists = errors.New("cgroup does not exist in the collector")
 )
 
 // Trigger will be called when an event happens and provides the cgroup
 // where the event originated from
 type Trigger func(string, string, cgroups.Cgroup)
 
-// New registers the Collector with the provided namespace and returns it so
+// newCollector registers the collector with the provided namespace and returns it so
 // that cgroups can be added for collection
-func NewCollector(ns *metrics.Namespace) *Collector {
+func newCollector(ns *metrics.Namespace) *collector {
 	if ns == nil {
-		return &Collector{}
+		return &collector{}
 	}
 	// add machine cpus and memory info
-	c := &Collector{
+	c := &collector{
 		ns:      ns,
 		cgroups: make(map[string]*task),
 	}
@@ -52,9 +54,9 @@ func taskID(id, namespace string) string {
 	return fmt.Sprintf("%s-%s", id, namespace)
 }
 
-// Collector provides the ability to collect container stats and export
+// collector provides the ability to collect container stats and export
 // them in the prometheus format
-type Collector struct {
+type collector struct {
 	mu sync.RWMutex
 
 	cgroups map[string]*task
@@ -62,13 +64,13 @@ type Collector struct {
 	metrics []*metric
 }
 
-func (c *Collector) Describe(ch chan<- *prometheus.Desc) {
+func (c *collector) Describe(ch chan<- *prometheus.Desc) {
 	for _, m := range c.metrics {
 		ch <- m.desc(c.ns)
 	}
 }
 
-func (c *Collector) Collect(ch chan<- prometheus.Metric) {
+func (c *collector) Collect(ch chan<- prometheus.Metric) {
 	c.mu.RLock()
 	wg := &sync.WaitGroup{}
 	for _, t := range c.cgroups {
@@ -79,7 +81,7 @@ func (c *Collector) Collect(ch chan<- prometheus.Metric) {
 	wg.Wait()
 }
 
-func (c *Collector) collect(id, namespace string, cg cgroups.Cgroup, ch chan<- prometheus.Metric, wg *sync.WaitGroup) {
+func (c *collector) collect(id, namespace string, cg cgroups.Cgroup, ch chan<- prometheus.Metric, wg *sync.WaitGroup) {
 	defer wg.Done()
 	stats, err := cg.Stat(cgroups.IgnoreNotExist)
 	if err != nil {
@@ -92,7 +94,7 @@ func (c *Collector) collect(id, namespace string, cg cgroups.Cgroup, ch chan<- p
 }
 
 // Add adds the provided cgroup and id so that metrics are collected and exported
-func (c *Collector) Add(id, namespace string, cg cgroups.Cgroup) error {
+func (c *collector) Add(id, namespace string, cg cgroups.Cgroup) error {
 	if c.ns == nil {
 		return nil
 	}
@@ -110,7 +112,7 @@ func (c *Collector) Add(id, namespace string, cg cgroups.Cgroup) error {
 }
 
 // Remove removes the provided cgroup by id from the collector
-func (c *Collector) Remove(id, namespace string) {
+func (c *collector) Remove(id, namespace string) {
 	if c.ns == nil {
 		return
 	}

metrics/cgroups/oom.go

@@ -14,7 +14,7 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-func NewOOMCollector(ns *metrics.Namespace) (*OOMCollector, error) {
+func newOOMCollector(ns *metrics.Namespace) (*oomCollector, error) {
 	fd, err := unix.EpollCreate1(unix.EPOLL_CLOEXEC)
 	if err != nil {
 		return nil, err
@@ -23,7 +23,7 @@ func NewOOMCollector(ns *metrics.Namespace) (*OOMCollector, error) {
 	if ns != nil {
 		desc = ns.NewDesc("memory_oom", "The number of times a container has received an oom event", metrics.Total, "container_id", "namespace")
 	}
-	c := &OOMCollector{
+	c := &oomCollector{
 		fd:   fd,
 		desc: desc,
 		set:  make(map[uintptr]*oom),
@@ -35,7 +35,7 @@ func NewOOMCollector(ns *metrics.Namespace) (*OOMCollector, error) {
 	return c, nil
 }
 
-type OOMCollector struct {
+type oomCollector struct {
 	mu sync.Mutex
 
 	desc *prometheus.Desc
@@ -51,7 +51,7 @@ type oom struct {
 	count     int64
 }
 
-func (o *OOMCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...Trigger) error {
+func (o *oomCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...Trigger) error {
 	o.mu.Lock()
 	defer o.mu.Unlock()
 	fd, err := cg.OOMEventFD()
@@ -71,11 +71,11 @@ func (o *OOMCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...
 	return unix.EpollCtl(o.fd, unix.EPOLL_CTL_ADD, int(fd), &event)
 }
 
-func (o *OOMCollector) Describe(ch chan<- *prometheus.Desc) {
+func (o *oomCollector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- o.desc
 }
 
-func (o *OOMCollector) Collect(ch chan<- prometheus.Metric) {
+func (o *oomCollector) Collect(ch chan<- prometheus.Metric) {
 	o.mu.Lock()
 	defer o.mu.Unlock()
 	for _, t := range o.set {
@@ -85,11 +85,11 @@ func (o *OOMCollector) Collect(ch chan<- prometheus.Metric) {
 }
 
 // Close closes the epoll fd
-func (o *OOMCollector) Close() error {
+func (o *oomCollector) Close() error {
 	return unix.Close(int(o.fd))
 }
 
-func (o *OOMCollector) start() {
+func (o *oomCollector) start() {
 	var events [128]unix.EpollEvent
 	for {
 		n, err := unix.EpollWait(o.fd, events[:], -1)
@@ -105,7 +105,7 @@ func (o *OOMCollector) start() {
 	}
 }
 
-func (o *OOMCollector) process(fd uintptr, event uint32) {
+func (o *oomCollector) process(fd uintptr, event uint32) {
 	// make sure to always flush the fd
 	flush(fd)