feat(processors.converter): Add support for base64 encoded IEEE floats (#16214)

plugins/processors/converter/README.md

@@ -67,6 +67,11 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
     boolean = []
     float = []
 
+    ## Optional field to use for converting base64 encoding of IEEE 754 Float32 values 
+    ## i.e. data_json_content_state_openconfig-platform-psu:output-power":"RKeAAA=="
+    ## into a float32 value 1340
+    # base64_ieee_float32 = []
+
     ## Optional field to use as metric timestamp
     # timestamp = []
 

plugins/processors/converter/converter.go

@@ -3,9 +3,12 @@ package converter
 
 import (
 	_ "embed"
+	"encoding/base64"
 	"errors"
+	"fmt"
 	"math"
 	"math/big"
+	"strconv"
 	"strings"
 
 	"github.com/influxdata/telegraf"
@@ -27,6 +30,7 @@ type Conversion struct {
 	Float             []string `toml:"float"`
 	Timestamp         []string `toml:"timestamp"`
 	TimestampFormat   string   `toml:"timestamp_format"`
+	Base64IEEEFloat32 []string `toml:"base64_ieee_float32"`
 }
 
 type Converter struct {
@@ -47,6 +51,7 @@ type ConversionFilter struct {
 	Boolean           filter.Filter
 	Float             filter.Filter
 	Timestamp         filter.Filter
+	Base64IEEEFloat32 filter.Filter
 }
 
 func (*Converter) SampleConfig() string {
@@ -132,6 +137,11 @@ func compileFilter(conv *Conversion) (*ConversionFilter, error) {
 		return nil, err
 	}
 
+	cf.Base64IEEEFloat32, err = filter.Compile(conv.Base64IEEEFloat32)
+	if err != nil {
+		return nil, err
+	}
+
 	return cf, nil
 }
 
@@ -249,6 +259,14 @@ func (p *Converter) convertFields(metric telegraf.Metric) {
 				metric.SetTime(time)
 				metric.RemoveField(key)
 			}
+
+		case p.fieldConversions.Base64IEEEFloat32 != nil && p.fieldConversions.Base64IEEEFloat32.Match(key):
+			if v, err := base64ToFloat32(value.(string)); err != nil {
+				p.Log.Errorf("Converting to base64_ieee_float32 [%T] failed: %v", value, err)
+				metric.RemoveField(key)
+			} else {
+				metric.AddField(key, v)
+			}
 		}
 	}
 }
@@ -345,6 +363,32 @@ func toFloat(v interface{}) (float64, error) {
 	return internal.ToFloat64(v)
 }
 
+func base64ToFloat32(encoded string) (float32, error) {
+	// Decode the Base64 string to bytes
+	decodedBytes, err := base64.StdEncoding.DecodeString(encoded)
+	if err != nil {
+		return 0, err
+	}
+
+	// Check if the byte length matches a float32 (4 bytes)
+	if len(decodedBytes) != 4 {
+		return 0, errors.New("decoded byte length is not 4 bytes")
+	}
+
+	// Convert the bytes to a string representation as per IEEE 754 of the bits
+	bitsStrRepresentation := fmt.Sprintf("%08b%08b%08b%08b", decodedBytes[0], decodedBytes[1], decodedBytes[2], decodedBytes[3])
+
+	// Convert the bits to a uint32
+	bits, err := strconv.ParseUint(bitsStrRepresentation, 2, 32)
+
+	if err != nil {
+		return 0, err
+	}
+
+	// Convert the uint32 (bits) to a float32 based on IEEE 754 binary representation
+	return math.Float32frombits(uint32(bits)), nil
+}
+
 func init() {
 	processors.Add("converter", func() telegraf.Processor {
 		return &Converter{}

plugins/processors/converter/converter_test.go

@@ -770,6 +770,34 @@ func TestMeasurement(t *testing.T) {
 				),
 			},
 		},
+		{
+			name: "float32 from ieee754 float32 encoded as base64",
+			converter: &Converter{
+				Fields: &Conversion{
+					Base64IEEEFloat32: []string{"a", "b"},
+				},
+			},
+			input: testutil.MustMetric(
+				"cpu",
+				map[string]string{},
+				map[string]interface{}{
+					"a": "QlAAAA==",
+					"b": "QlgAAA==",
+				},
+				time.Unix(0, 0),
+			),
+			expected: []telegraf.Metric{
+				testutil.MustMetric(
+					"cpu",
+					map[string]string{},
+					map[string]interface{}{
+						"a": float32(52),
+						"b": float32(54),
+					},
+					time.Unix(0, 0),
+				),
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

plugins/processors/converter/sample.conf

@@ -35,6 +35,11 @@
     boolean = []
     float = []
 
+    ## Optional field to use for converting base64 encoding of IEEE 754 Float32 values 
+    ## i.e. data_json_content_state_openconfig-platform-psu:output-power":"RKeAAA=="
+    ## into a float32 value 1340
+    # base64_ieee_float32 = []
+
     ## Optional field to use as metric timestamp
     # timestamp = []