feat(agent): Add option to avoid filtering of global tags (#13605)

config/config.go

@@ -263,6 +263,10 @@ type AgentConfig struct {
 	// Flag to always keep tags explicitly defined in the plugin itself and
 	// ensure those tags always pass filtering.
 	AlwaysIncludeLocalTags bool `toml:"always_include_local_tags"`
+
+	// Flag to always keep tags explicitly defined in the global tags section
+	// and ensure those tags always pass filtering.
+	AlwaysIncludeGlobalTags bool `toml:"always_include_global_tags"`
 }
 
 // InputNames returns a list of strings of the configured inputs.
@@ -1461,6 +1465,7 @@ func (c *Config) buildInput(name string, tbl *ast.Table) (*models.InputConfig, e
 	cp := &models.InputConfig{
 		Name:                    name,
 		AlwaysIncludeLocalTags:  c.Agent.AlwaysIncludeLocalTags,
+		AlwaysIncludeGlobalTags: c.Agent.AlwaysIncludeGlobalTags,
 	}
 	c.getFieldDuration(tbl, "interval", &cp.Interval)
 	c.getFieldDuration(tbl, "precision", &cp.Precision)

docs/CONFIGURATION.md

@@ -326,6 +326,11 @@ The agent table configures Telegraf and the defaults used across all plugins.
   via `taginclude` or `tagexclude`. This removes the need to specify local tags
   twice.
 
+- **always_include_global_tags**:
+  Ensure tags explicitly defined in the `global_tags` section will *always* pass
+  tag-filtering   via `taginclude` or `tagexclude`. This removes the need to
+  specify those tags twice.
+
 ## Plugins
 
 Telegraf plugins are divided into 4 types: [inputs][], [outputs][],

models/running_input.go

@@ -77,6 +77,7 @@ type InputConfig struct {
 	Tags                    map[string]string
 	Filter                  Filter
 	AlwaysIncludeLocalTags  bool
+	AlwaysIncludeGlobalTags bool
 }
 
 func (r *RunningInput) metricFiltered(metric telegraf.Metric) {
@@ -113,17 +114,12 @@ func (r *RunningInput) MakeMetric(metric telegraf.Metric) telegraf.Metric {
 		return nil
 	}
 
-	tags := r.Config.Tags
+	makemetric(
-	if r.Config.AlwaysIncludeLocalTags {
-		tags = nil
-	}
-
-	m := makemetric(
 		metric,
 		r.Config.NameOverride,
 		r.Config.MeasurementPrefix,
 		r.Config.MeasurementSuffix,
-		tags,
+		r.Config.Tags,
 		r.defaultTags)
 
 	r.Config.Filter.Modify(metric)
@@ -132,18 +128,20 @@ func (r *RunningInput) MakeMetric(metric telegraf.Metric) telegraf.Metric {
 		return nil
 	}
 
+	if r.Config.AlwaysIncludeLocalTags || r.Config.AlwaysIncludeGlobalTags {
+		var local, global map[string]string
 		if r.Config.AlwaysIncludeLocalTags {
-		// Apply plugin tags after filtering
+			local = r.Config.Tags
-		for k, v := range r.Config.Tags {
-			if _, ok := metric.GetTag(k); !ok {
-				metric.AddTag(k, v)
 		}
+		if r.Config.AlwaysIncludeGlobalTags {
+			global = r.defaultTags
 		}
+		makemetric(metric, "", "", "", local, global)
 	}
 
 	r.MetricsGathered.Incr(1)
 	GlobalMetricsGathered.Incr(1)
-	return m
+	return metric
 }
 
 func (r *RunningInput) Gather(acc telegraf.Accumulator) error {

models/running_input_test.go

@@ -55,8 +55,8 @@ func TestMakeMetricNoFields(t *testing.T) {
 		map[string]interface{}{},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
-	assert.Nil(t, m)
+	require.Nil(t, actual)
 }
 
 // nil fields should get dropped
@@ -74,7 +74,7 @@ func TestMakeMetricNilFields(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
 
 	expected := metric.New("RITest",
 		map[string]string{},
@@ -84,7 +84,7 @@ func TestMakeMetricNilFields(t *testing.T) {
 		now,
 	)
 
-	require.Equal(t, expected, m)
+	require.Equal(t, expected, actual)
 }
 
 func TestMakeMetricWithPluginTags(t *testing.T) {
@@ -103,7 +103,7 @@ func TestMakeMetricWithPluginTags(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
 
 	expected := metric.New("RITest",
 		map[string]string{
@@ -114,7 +114,7 @@ func TestMakeMetricWithPluginTags(t *testing.T) {
 		},
 		now,
 	)
-	require.Equal(t, expected, m)
+	require.Equal(t, expected, actual)
 }
 
 func TestMakeMetricFilteredOut(t *testing.T) {
@@ -136,8 +136,8 @@ func TestMakeMetricFilteredOut(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
-	assert.Nil(t, m)
+	require.Nil(t, actual)
 }
 
 func TestMakeMetricWithDaemonTags(t *testing.T) {
@@ -156,7 +156,7 @@ func TestMakeMetricWithDaemonTags(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
 	expected := metric.New("RITest",
 		map[string]string{
 			"foo": "bar",
@@ -166,7 +166,7 @@ func TestMakeMetricWithDaemonTags(t *testing.T) {
 		},
 		now,
 	)
-	require.Equal(t, expected, m)
+	require.Equal(t, expected, actual)
 }
 
 func TestMakeMetricNameOverride(t *testing.T) {
@@ -183,7 +183,7 @@ func TestMakeMetricNameOverride(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
 	expected := metric.New("foobar",
 		nil,
 		map[string]interface{}{
@@ -191,7 +191,7 @@ func TestMakeMetricNameOverride(t *testing.T) {
 		},
 		now,
 	)
-	require.Equal(t, expected, m)
+	require.Equal(t, expected, actual)
 }
 
 func TestMakeMetricNamePrefix(t *testing.T) {
@@ -208,7 +208,7 @@ func TestMakeMetricNamePrefix(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
 	expected := metric.New("foobar_RITest",
 		nil,
 		map[string]interface{}{
@@ -216,7 +216,7 @@ func TestMakeMetricNamePrefix(t *testing.T) {
 		},
 		now,
 	)
-	require.Equal(t, expected, m)
+	require.Equal(t, expected, actual)
 }
 
 func TestMakeMetricNameSuffix(t *testing.T) {
@@ -233,7 +233,7 @@ func TestMakeMetricNameSuffix(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
 	expected := metric.New("RITest_foobar",
 		nil,
 		map[string]interface{}{
@@ -241,7 +241,7 @@ func TestMakeMetricNameSuffix(t *testing.T) {
 		},
 		now,
 	)
-	require.Equal(t, expected, m)
+	require.Equal(t, expected, actual)
 }
 
 func TestMetricErrorCounters(t *testing.T) {
@@ -283,8 +283,8 @@ func TestMakeMetricWithAlwaysKeepingPluginTagsDisabled(t *testing.T) {
 		Filter: Filter{
 			TagInclude: []string{"b"},
 		},
-		AlwaysIncludeLocalTags: false,
 	})
+	ri.SetDefaultTags(map[string]string{"logic": "rulez"})
 	require.NoError(t, ri.Config.Filter.Compile())
 
 	m := testutil.MustMetric("RITest",
@@ -296,7 +296,7 @@ func TestMakeMetricWithAlwaysKeepingPluginTagsDisabled(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
 
 	expected := metric.New("RITest",
 		map[string]string{
@@ -307,7 +307,85 @@ func TestMakeMetricWithAlwaysKeepingPluginTagsDisabled(t *testing.T) {
 		},
 		now,
 	)
-	require.Equal(t, expected, m)
+	require.Equal(t, expected, actual)
+}
+
+func TestMakeMetricWithAlwaysKeepingLocalPluginTagsEnabled(t *testing.T) {
+	now := time.Now()
+	ri := NewRunningInput(&testInput{}, &InputConfig{
+		Name: "TestRunningInput",
+		Tags: map[string]string{
+			"foo": "bar",
+		},
+		Filter: Filter{
+			TagInclude: []string{"b"},
+		},
+		AlwaysIncludeLocalTags: true,
+	})
+	ri.SetDefaultTags(map[string]string{"logic": "rulez"})
+	require.NoError(t, ri.Config.Filter.Compile())
+
+	m := testutil.MustMetric("RITest",
+		map[string]string{
+			"b": "test",
+		},
+		map[string]interface{}{
+			"value": int64(101),
+		},
+		now,
+		telegraf.Untyped)
+	actual := ri.MakeMetric(m)
+
+	expected := metric.New("RITest",
+		map[string]string{
+			"b":   "test",
+			"foo": "bar",
+		},
+		map[string]interface{}{
+			"value": 101,
+		},
+		now,
+	)
+	require.Equal(t, expected, actual)
+}
+
+func TestMakeMetricWithAlwaysKeepingGlobalPluginTagsEnabled(t *testing.T) {
+	now := time.Now()
+	ri := NewRunningInput(&testInput{}, &InputConfig{
+		Name: "TestRunningInput",
+		Tags: map[string]string{
+			"foo": "bar",
+		},
+		Filter: Filter{
+			TagInclude: []string{"b"},
+		},
+		AlwaysIncludeGlobalTags: true,
+	})
+	ri.SetDefaultTags(map[string]string{"logic": "rulez"})
+	require.NoError(t, ri.Config.Filter.Compile())
+
+	m := testutil.MustMetric("RITest",
+		map[string]string{
+			"b": "test",
+		},
+		map[string]interface{}{
+			"value": int64(101),
+		},
+		now,
+		telegraf.Untyped)
+	actual := ri.MakeMetric(m)
+
+	expected := metric.New("RITest",
+		map[string]string{
+			"b":     "test",
+			"logic": "rulez",
+		},
+		map[string]interface{}{
+			"value": 101,
+		},
+		now,
+	)
+	require.Equal(t, expected, actual)
 }
 
 func TestMakeMetricWithAlwaysKeepingPluginTagsEnabled(t *testing.T) {
@@ -321,7 +399,9 @@ func TestMakeMetricWithAlwaysKeepingPluginTagsEnabled(t *testing.T) {
 			TagInclude: []string{"b"},
 		},
 		AlwaysIncludeLocalTags:  true,
+		AlwaysIncludeGlobalTags: true,
 	})
+	ri.SetDefaultTags(map[string]string{"logic": "rulez"})
 	require.NoError(t, ri.Config.Filter.Compile())
 
 	m := testutil.MustMetric("RITest",
@@ -333,19 +413,20 @@ func TestMakeMetricWithAlwaysKeepingPluginTagsEnabled(t *testing.T) {
 		},
 		now,
 		telegraf.Untyped)
-	m = ri.MakeMetric(m)
+	actual := ri.MakeMetric(m)
 
 	expected := metric.New("RITest",
 		map[string]string{
 			"b":     "test",
 			"foo":   "bar",
+			"logic": "rulez",
 		},
 		map[string]interface{}{
 			"value": 101,
 		},
 		now,
 	)
-	require.Equal(t, expected, m)
+	require.Equal(t, expected, actual)
 }
 
 type testInput struct{}