Support Go execd plugins with shim (#7283)

plugins/inputs/execd/execd_test.go

@@ -0,0 +1,85 @@
+// +build !windows
+
+package execd
+
+import (
+	"testing"
+	"time"
+
+	"github.com/influxdata/telegraf/agent"
+	"github.com/influxdata/telegraf/config"
+	"github.com/influxdata/telegraf/models"
+	"github.com/stretchr/testify/require"
+
+	"github.com/influxdata/telegraf/plugins/parsers"
+
+	"github.com/influxdata/telegraf"
+)
+
+func TestExternalInputWorks(t *testing.T) {
+	jsonParser, err := parsers.NewInfluxParser()
+	require.NoError(t, err)
+
+	e := &Execd{
+		Command:      []string{shell(), fileShellScriptPath()},
+		RestartDelay: config.Duration(5 * time.Second),
+		parser:       jsonParser,
+		Signal:       "STDIN",
+	}
+
+	metrics := make(chan telegraf.Metric, 10)
+	defer close(metrics)
+	acc := agent.NewAccumulator(&TestMetricMaker{}, metrics)
+
+	require.NoError(t, e.Start(acc))
+	require.NoError(t, e.Gather(acc))
+	e.Stop()
+
+	// grab a metric and make sure it's a thing
+	m := readChanWithTimeout(t, metrics, 10*time.Second)
+
+	require.Equal(t, "counter_bash", m.Name())
+	val, ok := m.GetField("count")
+	require.True(t, ok)
+	require.Equal(t, float64(0), val)
+	// test that a later gather will not panic
+	e.Gather(acc)
+}
+
+func readChanWithTimeout(t *testing.T, metrics chan telegraf.Metric, timeout time.Duration) telegraf.Metric {
+	to := time.NewTimer(timeout)
+	defer to.Stop()
+	select {
+	case m := <-metrics:
+		return m
+	case <-to.C:
+		require.FailNow(t, "timeout waiting for metric")
+	}
+	return nil
+}
+
+func fileShellScriptPath() string {
+	return "./examples/count.sh"
+}
+
+func shell() string {
+	return "sh"
+}
+
+type TestMetricMaker struct{}
+
+func (tm *TestMetricMaker) Name() string {
+	return "TestPlugin"
+}
+
+func (tm *TestMetricMaker) LogName() string {
+	return tm.Name()
+}
+
+func (tm *TestMetricMaker) MakeMetric(metric telegraf.Metric) telegraf.Metric {
+	return metric
+}
+
+func (tm *TestMetricMaker) Log() telegraf.Logger {
+	return models.NewLogger("TestPlugin", "test", "")
+}