Add support for defining custom colors

README.md

@@ -215,9 +215,11 @@ By default, the build result and intermediate cache will only remain internally
 
 > Color Output Controls
 >
-> `buildctl` has support for modifying the colors that are used to output information to the terminal. You can set the environment varliable `BUILDKIT_COLORS` to something like `run=blue;cancel=yellow;warn=orange;error=red` to set the colors that you would like to use. You can also set `NO_COLOR` to disable colorized output.
+> `buildctl` has support for modifying the colors that are used to output information to the terminal. You can set the environment variable `BUILDKIT_COLORS` to something like `run=blue;cancel=yellow;warn=orange;error=123,12,0` to set the colors that you would like to use. You can also set `NO_COLOR` to disable colorized output.
 >
-> - [A list of the supported colors](https://github.com/moby/buildkit/blob/master/util/progress/progressui/colors.go).
+> Parsing errors will be reported, but ignored. This will result in default color values being used where needed.
+>
+> - [The list of pre-defined colors](https://github.com/moby/buildkit/blob/master/util/progress/progressui/colors.go).
 
 #### Image/Registry
 

util/progress/progressui/colors.go

@@ -1,15 +1,14 @@
 package progressui
 
 import (
-	"fmt"
-	"regexp"
+	"encoding/csv"
+	"strconv"
 	"strings"
 
 	"github.com/morikuni/aec"
+	"github.com/sirupsen/logrus"
 )
 
-var rex = regexp.MustCompile(`(\w+)=(\w+)`)
-
 var termColorMap = map[string]aec.ANSI{
 	"default": aec.DefaultF,
 
@@ -35,25 +34,109 @@ var termColorMap = map[string]aec.ANSI{
 }
 
 func setUserDefinedTermColors(colorsEnv string) {
-	data := rex.FindAllStringSubmatch(colorsEnv, -1)
-	for _, kv := range data {
-		k := kv[1]
-		v := kv[2]
-		// debug
-		fmt.Print(k, "=", v)
+	fields := readBuildkitColorsEnv(colorsEnv)
+	if fields == nil {
+		return
+	}
+	for _, field := range fields {
+		parts := strings.SplitN(field, "=", 2)
+		if len(parts) != 2 {
+			logrus.Warnf("Could not parse BUILDKIT_COLORS component: %s", strings.Join(parts, "="))
+			continue
+		}
+		if strings.Contains(parts[1], "=") {
+			logrus.Warnf("Could not parse BUILDKIT_COLORS component: %s", strings.Join(parts, "="))
+			continue
+		}
+		k := strings.ToLower(parts[0])
+		v := parts[1]
 		c, ok := termColorMap[strings.ToLower(v)]
 		if ok {
-			key := strings.ToLower(k)
-			switch key {
-			case "run":
-				colorRun = c
-			case "cancel":
-				colorCancel = c
-			case "error":
-				colorError = c
-			case "warning":
-				colorWarning = c
+			parseKeys(k, c)
+		} else {
+			if strings.Contains(v, ",") {
+				rgbFields := readRGB(v)
+				if rgbFields == nil {
+					continue
+				}
+				ok = isValidRGB(rgbFields)
+				if ok {
+					p1, _ := strconv.Atoi(rgbFields[0])
+					p2, _ := strconv.Atoi(rgbFields[1])
+					p3, _ := strconv.Atoi(rgbFields[2])
+					c = aec.Color8BitF(aec.NewRGB8Bit(uint8(p1), uint8(p2), uint8(p3)))
+					parseKeys(k, c)
+				}
+			} else {
+				logrus.Warnf("Unknown color value found in BUILDKIT_COLORS: %s=%s", k, v)
 			}
 		}
 	}
 }
+
+func readBuildkitColorsEnv(colorsEnv string) []string {
+	csvReader := csv.NewReader(strings.NewReader(colorsEnv))
+	csvReader.Comma = ':' // Use colon instead of comma
+	fields, err := csvReader.Read()
+	if err != nil {
+		logrus.WithError(err).Warnf("Could not parse BUILDKIT_COLORS. Falling back to defaults.")
+		return nil
+	}
+	return fields
+}
+
+func readRGB(v string) []string {
+	csvReader := csv.NewReader(strings.NewReader(v))
+	csvReader.Comma = ',' // Use colon instead of comma
+	fields, err := csvReader.Read()
+	if err != nil {
+		logrus.WithError(err).Warnf("Could not parse value %s as valid RGB color. Ignoring.", v)
+		return nil
+	}
+	if len(fields) != 3 {
+		logrus.Warnf("Could not parse value %s as valid RGB color. Ignoring.", v)
+		return nil
+	}
+	return fields
+}
+
+func parseKeys(k string, c aec.ANSI) {
+	key := strings.ToLower(k)
+	switch key {
+	case "run":
+		colorRun = c
+	case "cancel":
+		colorCancel = c
+	case "error":
+		colorError = c
+	case "warning":
+		colorWarning = c
+	default:
+		logrus.Warnf("Unknown key found in BUILDKIT_COLORS (expected: run, cancel, error, or warning): %s", k)
+	}
+}
+
+func isValidRGB(s []string) bool {
+	for _, n := range s {
+		num, err := strconv.Atoi(n)
+		if err != nil {
+			logrus.Warnf("A field in BUILDKIT_COLORS appears to contain an RGB value that is not an integer: %s", strings.Join(s, ","))
+			return false
+		}
+		ok := isValidRGBValue(num)
+		if ok {
+			continue
+		} else {
+			logrus.Warnf("A field in BUILDKIT_COLORS appears to contain an RGB value that is not within the valid range of 0-255: %s", strings.Join(s, ","))
+			return false
+		}
+	}
+	return true
+}
+
+func isValidRGBValue(i int) bool {
+	if (i >= 0) && (i <= 255) {
+		return true
+	}
+	return false
+}