kpod stats

Move kpod stats to the libpod backend.

Signed-off-by: baude <bbaude@redhat.com>

Closes: #113
Approved by: baude

5 files changed, 188 insertions, 1 deletions

diff --git a/libpod/container.go b/libpod/container.go
index d53a863c0..604b5fe10 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -11,6 +11,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/containerd/cgroups"
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/archive"
 	"github.com/docker/docker/daemon/caps"
@@ -55,6 +56,9 @@ const (
 	artifactsDir = "artifacts"
 )
 
+// CGroupParent is the prefix to a cgroup path in libpod
+var CGroupParent = "/libpod_parent"
+
 // Container is a single OCI container
 type Container struct {
 	config *ContainerConfig
@@ -577,7 +581,7 @@ func (c *Container) Init() (err error) {
 
 	// With the spec complete, do an OCI create
 	// TODO set cgroup parent in a sane fashion
-	if err := c.runtime.ociRuntime.createContainer(c, "/libpod_parent"); err != nil {
+	if err := c.runtime.ociRuntime.createContainer(c, CGroupParent); err != nil {
 		return err
 	}
 
@@ -1044,3 +1048,8 @@ func (c *Container) cleanupStorage() error {
 
 	return c.save()
 }
+
+// CGroupPath returns a cgroups "path" for a given container.
+func (c *Container) CGroupPath() cgroups.Path {
+	return cgroups.StaticPath(filepath.Join(CGroupParent, fmt.Sprintf("libpod-conmon-%s", c.ID())))
+}
diff --git a/libpod/runtime_ctr.go b/libpod/runtime_ctr.go
index f314b302f..320821b38 100644
--- a/libpod/runtime_ctr.go
+++ b/libpod/runtime_ctr.go
@@ -232,3 +232,31 @@ func (r *Runtime) GetContainers(filters ...ContainerFilter) ([]*Container, error
 
 	return ctrsFiltered, nil
 }
+
+// GetAllContainers is a helper function for GetContainers
+func (r *Runtime) GetAllContainers() ([]*Container, error) {
+	return r.state.AllContainers()
+}
+
+// GetRunningContainers is a helper function for GetContainers
+func (r *Runtime) GetRunningContainers() ([]*Container, error) {
+	running := func(c *Container) bool {
+		state, _ := c.State()
+		return state == ContainerStateRunning
+	}
+	return r.GetContainers(running)
+}
+
+// GetContainersByList is a helper function for GetContainers
+// which takes a []string of container IDs or names
+func (r *Runtime) GetContainersByList(containers []string) ([]*Container, error) {
+	var ctrs []*Container
+	for _, inputContainer := range containers {
+		ctr, err := r.LookupContainer(inputContainer)
+		if err != nil {
+			return ctrs, errors.Wrapf(err, "unable to lookup container %s", inputContainer)
+		}
+		ctrs = append(ctrs, ctr)
+	}
+	return ctrs, nil
+}
diff --git a/libpod/stats.go b/libpod/stats.go
new file mode 100644
index 000000000..86da0679e
--- /dev/null
+++ b/libpod/stats.go
@@ -0,0 +1,120 @@
+package libpod
+
+import (
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/containerd/cgroups"
+	"github.com/opencontainers/runc/libcontainer"
+	"github.com/pkg/errors"
+)
+
+// ContainerStats contains the statistics information for a running container
+type ContainerStats struct {
+	ContainerID string
+	CPU         float64
+	CPUNano     uint64
+	SystemNano  uint64
+	MemUsage    uint64
+	MemLimit    uint64
+	MemPerc     float64
+	NetInput    uint64
+	NetOutput   uint64
+	BlockInput  uint64
+	BlockOutput uint64
+	PIDs        uint64
+}
+
+// GetContainerStats gets the running stats for a given container
+func (c *Container) GetContainerStats(previousStats *ContainerStats) (*ContainerStats, error) {
+	stats := new(ContainerStats)
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	if err := c.syncContainer(); err != nil {
+		return stats, errors.Wrapf(err, "error updating container %s state", c.ID())
+	}
+	cgroup, err := cgroups.Load(cgroups.V1, c.CGroupPath())
+	if err != nil {
+		return stats, errors.Wrapf(err, "unable to load cgroup at %+v", c.CGroupPath())
+	}
+
+	cgroupStats, err := cgroup.Stat()
+	if err != nil {
+		return stats, errors.Wrapf(err, "unable to obtain cgroup stats")
+	}
+	conState := c.state.State
+	if err != nil {
+		return stats, errors.Wrapf(err, "unable to determine container state")
+	}
+
+	previousCPU := previousStats.CPUNano
+	previousSystem := previousStats.SystemNano
+	stats.ContainerID = c.ID()
+	stats.CPU = calculateCPUPercent(cgroupStats, previousCPU, previousSystem)
+	stats.MemUsage = cgroupStats.Memory.Usage.Usage
+	stats.MemLimit = getMemLimit(cgroupStats.Memory.Usage.Limit)
+	stats.MemPerc = (float64(stats.MemUsage) / float64(stats.MemLimit)) * 100
+	stats.PIDs = 0
+	if conState == ContainerStateRunning {
+		stats.PIDs = cgroupStats.Pids.Current - 1
+	}
+	stats.BlockInput, stats.BlockOutput = calculateBlockIO(cgroupStats)
+	stats.CPUNano = cgroupStats.Cpu.Usage.Total
+	stats.SystemNano = cgroupStats.Cpu.Usage.Kernel
+	// TODO Figure out where to get the Netout stuff.
+	//stats.NetInput, stats.NetOutput = getContainerNetIO(cgroupStats)
+	return stats, nil
+}
+
+// getMemory limit returns the memory limit for a given cgroup
+// If the configured memory limit is larger than the total memory on the sys, the
+// physical system memory size is returned
+func getMemLimit(cgroupLimit uint64) uint64 {
+	si := &syscall.Sysinfo_t{}
+	err := syscall.Sysinfo(si)
+	if err != nil {
+		return cgroupLimit
+	}
+
+	physicalLimit := uint64(si.Totalram)
+	if cgroupLimit > physicalLimit {
+		return physicalLimit
+	}
+	return cgroupLimit
+}
+
+// Returns the total number of bytes transmitted and received for the given container stats
+func getContainerNetIO(stats *libcontainer.Stats) (received uint64, transmitted uint64) { //nolint
+	for _, iface := range stats.Interfaces {
+		received += iface.RxBytes
+		transmitted += iface.TxBytes
+	}
+	return
+}
+
+func calculateCPUPercent(stats *cgroups.Stats, previousCPU, previousSystem uint64) float64 {
+	var (
+		cpuPercent  = 0.0
+		cpuDelta    = float64(stats.Cpu.Usage.Total - previousCPU)
+		systemDelta = float64(uint64(time.Now().UnixNano()) - previousSystem)
+	)
+	if systemDelta > 0.0 && cpuDelta > 0.0 {
+		// gets a ratio of container cpu usage total, multiplies it by the number of cores (4 cores running
+		// at 100% utilization should be 400% utilization), and multiplies that by 100 to get a percentage
+		cpuPercent = (cpuDelta / systemDelta) * float64(len(stats.Cpu.Usage.PerCpu)) * 100
+	}
+	return cpuPercent
+}
+
+func calculateBlockIO(stats *cgroups.Stats) (read uint64, write uint64) {
+	for _, blkIOEntry := range stats.Blkio.IoServiceBytesRecursive {
+		switch strings.ToLower(blkIOEntry.Op) {
+		case "read":
+			read += blkIOEntry.Value
+		case "write":
+			write += blkIOEntry.Value
+		}
+	}
+	return
+}
diff --git a/libpod/util.go b/libpod/util.go
index 61089b525..de5c3ff31 100644
--- a/libpod/util.go
+++ b/libpod/util.go
@@ -9,6 +9,8 @@ import (
 
 	"github.com/containers/image/signature"
 	"github.com/containers/image/types"
+	"github.com/pkg/errors"
+	"strconv"
 )
 
 // Runtime API constants
@@ -76,3 +78,21 @@ func GetPolicyContext(path string) (*signature.PolicyContext, error) {
 	}
 	return signature.NewPolicyContext(policy)
 }
+
+// RemoveScientificNotationFromFloat returns a float without any
+// scientific notation if the number has any.
+// golang does not handle conversion of float64s that have scientific
+// notation in them and otherwise stinks.  please replace this if you have
+// a better implementation.
+func RemoveScientificNotationFromFloat(x float64) (float64, error) {
+	bigNum := strconv.FormatFloat(x, 'g', -1, 64)
+	breakPoint := strings.IndexAny(bigNum, "Ee")
+	if breakPoint > 0 {
+		bigNum = bigNum[:breakPoint]
+	}
+	result, err := strconv.ParseFloat(bigNum, 64)
+	if err != nil {
+		return x, errors.Wrapf(err, "unable to remove scientific number from calculations")
+	}
+	return result, nil
+}
diff --git a/libpod/util_test.go b/libpod/util_test.go
index 24e5fdfac..7b9d19a43 100644
--- a/libpod/util_test.go
+++ b/libpod/util_test.go
@@ -17,3 +17,13 @@ func TestStringInSlice(t *testing.T) {
 	// string is not in empty slice
 	assert.False(t, StringInSlice("one", []string{}))
 }
+
+func TestRemoveScientificNotationFromFloat(t *testing.T) {
+	numbers := []float64{0.0, .5, 1.99999932, 1.04e+10}
+	results := []float64{0.0, .5, 1.99999932, 1.04}
+	for i, x := range numbers {
+		result, err := RemoveScientificNotationFromFloat(x)
+		assert.NoError(t, err)
+		assert.Equal(t, result, results[i])
+	}
+}