Initial spike

This is mostly to solidify the overall structure with the agent,
plugins, and testing philosphy.

plugins/all/all.go

@@ -0,0 +1,5 @@
+package all
+
+import (
+	_ "github.com/influxdb/tivan/plugins/system"
+)

plugins/mock_Plugin.go

@@ -0,0 +1,18 @@
+package plugins
+
+import "github.com/stretchr/testify/mock"
+
+import "github.com/vektra/cypress"
+
+type MockPlugin struct {
+	mock.Mock
+}
+
+func (m *MockPlugin) Read() ([]*cypress.Message, error) {
+	ret := m.Called()
+
+	r0 := ret.Get(0).([]*cypress.Message)
+	r1 := ret.Error(1)
+
+	return r0, r1
+}

plugins/registry.go

@@ -0,0 +1,15 @@
+package plugins
+
+import "github.com/vektra/cypress"
+
+type Plugin interface {
+	Read() ([]*cypress.Message, error)
+}
+
+type Creator func() Plugin
+
+var Plugins = map[string]Creator{}
+
+func Add(name string, creator Creator) {
+	Plugins[name] = creator
+}

plugins/system/mock_PS.go

@@ -0,0 +1,18 @@
+package system
+
+import "github.com/stretchr/testify/mock"
+
+import "github.com/shirou/gopsutil/load"
+
+type MockPS struct {
+	mock.Mock
+}
+
+func (m *MockPS) LoadAvg() (*load.LoadAvgStat, error) {
+	ret := m.Called()
+
+	r0 := ret.Get(0).(*load.LoadAvgStat)
+	r1 := ret.Error(1)
+
+	return r0, r1
+}

plugins/system/system.go

@@ -0,0 +1,64 @@
+package system
+
+import (
+	"github.com/influxdb/tivan/plugins"
+	"github.com/shirou/gopsutil/load"
+	"github.com/vektra/cypress"
+)
+
+type PS interface {
+	LoadAvg() (*load.LoadAvgStat, error)
+}
+
+type SystemStats struct {
+	ps   PS
+	tags map[string]string
+}
+
+func (s *SystemStats) Read() ([]*cypress.Message, error) {
+	lv, err := s.ps.LoadAvg()
+	if err != nil {
+		return nil, err
+	}
+
+	m1 := cypress.Metric()
+	m1.Add("type", "gauge")
+	m1.Add("name", "load1")
+	m1.Add("value", lv.Load1)
+
+	for k, v := range s.tags {
+		m1.AddTag(k, v)
+	}
+
+	m2 := cypress.Metric()
+	m2.Add("type", "gauge")
+	m2.Add("name", "load5")
+	m2.Add("value", lv.Load5)
+
+	for k, v := range s.tags {
+		m2.AddTag(k, v)
+	}
+
+	m3 := cypress.Metric()
+	m3.Add("type", "gauge")
+	m3.Add("name", "load15")
+	m3.Add("value", lv.Load15)
+
+	for k, v := range s.tags {
+		m3.AddTag(k, v)
+	}
+
+	return []*cypress.Message{m1, m2, m3}, nil
+}
+
+type systemPS struct{}
+
+func (s *systemPS) LoadAvg() (*load.LoadAvgStat, error) {
+	return load.LoadAvg()
+}
+
+func init() {
+	plugins.Add("system", func() plugins.Plugin {
+		return &SystemStats{ps: &systemPS{}}
+	})
+}

plugins/system/system_test.go

@@ -0,0 +1,98 @@
+package system
+
+import (
+	"testing"
+
+	"github.com/shirou/gopsutil/load"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/vektra/neko"
+)
+
+func TestSystemStats(t *testing.T) {
+	n := neko.Start(t)
+
+	var mps MockPS
+
+	n.CheckMock(&mps.Mock)
+
+	n.It("generates metrics from the system information", func() {
+		ss := &SystemStats{ps: &mps}
+
+		lv := &load.LoadAvgStat{
+			Load1:  0.3,
+			Load5:  1.5,
+			Load15: 0.8,
+		}
+
+		mps.On("LoadAvg").Return(lv, nil)
+
+		msgs, err := ss.Read()
+		require.NoError(t, err)
+
+		name, ok := msgs[0].GetString("name")
+		require.True(t, ok)
+
+		assert.Equal(t, "load1", name)
+
+		val, ok := msgs[0].GetFloat("value")
+		require.True(t, ok)
+
+		assert.Equal(t, 0.3, val)
+
+		name, ok = msgs[1].GetString("name")
+		require.True(t, ok)
+
+		assert.Equal(t, "load5", name)
+
+		val, ok = msgs[1].GetFloat("value")
+		require.True(t, ok)
+
+		assert.Equal(t, 1.5, val)
+
+		name, ok = msgs[2].GetString("name")
+		require.True(t, ok)
+
+		assert.Equal(t, "load15", name)
+
+		val, ok = msgs[2].GetFloat("value")
+		require.True(t, ok)
+
+		assert.Equal(t, 0.8, val)
+	})
+
+	n.It("adds any tags registered", func() {
+		ss := &SystemStats{
+			ps: &mps,
+			tags: map[string]string{
+				"host": "my.test",
+				"dc":   "us-west-1",
+			},
+		}
+
+		lv := &load.LoadAvgStat{
+			Load1:  0.3,
+			Load5:  1.5,
+			Load15: 0.8,
+		}
+
+		mps.On("LoadAvg").Return(lv, nil)
+
+		msgs, err := ss.Read()
+		require.NoError(t, err)
+
+		for _, m := range msgs {
+			val, ok := m.GetTag("host")
+			require.True(t, ok)
+
+			assert.Equal(t, val, "my.test")
+
+			val, ok = m.GetTag("dc")
+			require.True(t, ok)
+
+			assert.Equal(t, val, "us-west-1")
+		}
+	})
+
+	n.Meow()
+}