Updating system plugins for 0.3.0

plugins/system/ps.go

@@ -1,12 +1,16 @@
 package system
 
 import (
+	"fmt"
 	gonet "net"
 	"os"
+	"reflect"
 	"strings"
+	"testing"
 
 	"github.com/influxdb/telegraf/internal"
 	"github.com/influxdb/telegraf/plugins"
+	"github.com/influxdb/telegraf/testutil"
 
 	dc "github.com/fsouza/go-dockerclient"
 	"github.com/shirou/gopsutil/cpu"
@@ -14,6 +18,8 @@ import (
 	"github.com/shirou/gopsutil/docker"
 	"github.com/shirou/gopsutil/mem"
 	"github.com/shirou/gopsutil/net"
+
+	"github.com/stretchr/testify/assert"
 )
 
 type DockerContainerStat struct {
@@ -166,3 +172,49 @@ func (s *systemPS) DockerStat() ([]*DockerContainerStat, error) {
 
 	return stats, nil
 }
+
+// Asserts that a given accumulator contains a measurment of type float64 with
+// specific tags within a certain distance of a given expected value. Asserts a failure
+// if the measurement is of the wrong type, or if no matching measurements are found
+//
+// Paramaters:
+//     t *testing.T            : Testing object to use
+//     acc testutil.Accumulator: Accumulator to examine
+//     measurement string      : Name of the measurement to examine
+//     expectedValue float64   : Value to search for within the measurement
+//     delta float64           : Maximum acceptable distance of an accumulated value
+//                               from the expectedValue parameter. Useful when
+//                               floating-point arithmatic imprecision makes looking
+//                               for an exact match impractical
+//     tags map[string]string  : Tag set the found measurement must have. Set to nil to
+//                               ignore the tag set.
+func assertContainsTaggedFloat(
+	t *testing.T,
+	acc *testutil.Accumulator,
+	measurement string,
+	expectedValue float64,
+	delta float64,
+	tags map[string]string,
+) {
+	var actualValue float64
+	for _, pt := range acc.Points {
+		if pt.Measurement == measurement {
+			if (tags == nil) || reflect.DeepEqual(pt.Tags, tags) {
+				if value, ok := pt.Fields["value"].(float64); ok {
+					actualValue = value
+					if (value >= expectedValue-delta) && (value <= expectedValue+delta) {
+						// Found the point, return without failing
+						return
+					}
+				} else {
+					assert.Fail(t, fmt.Sprintf("Measurement \"%s\" does not have type float64",
+						measurement))
+				}
+
+			}
+		}
+	}
+	msg := fmt.Sprintf("Could not find measurement \"%s\" with requested tags within %f of %f, Actual: %f",
+		measurement, delta, expectedValue, actualValue)
+	assert.Fail(t, msg)
+}