[logging] Adds a method for using specific messaging for known errors

logging/known_errors.go

@@ -0,0 +1,45 @@
+package logging
+
+import (
+  "fmt"
+  "strings"
+)
+
+// knownErrorPatterns Returns list of all known error patterns
+func knownErrorPatterns() []string {
+  return []string{
+    "error dialing DHCP daemon",
+  }
+}
+
+// getKnownErrorMessage returns
+func getKnownErrorMessage(patternkey string) (string, error) {
+  messages := map[string]string{
+    "error dialing DHCP daemon": "Please check that the DHCP CNI daemon is running and is properly configured.",
+  }
+
+  if val, ok := messages[patternkey]; ok {
+    return val, nil
+  }
+
+  return "", fmt.Errorf("Known error key '" + patternkey + "' does not have a message")
+
+}
+
+// detectKnownErrors detects the first known error given n number of stringers as passed to the logging methods
+func addKnownErrorMessage(a ...interface{}) string {
+  var knownerrormessage string
+  knownerrors := knownErrorPatterns()
+
+knownerrorloop:
+  for _, eachstringer := range a {
+    for _, eachknownerror := range knownerrors {
+      if strings.Contains(fmt.Sprintf("%s", eachstringer), eachknownerror) {
+        knownerrormessage, _ = getKnownErrorMessage(eachknownerror)
+        knownerrormessage = " (" + knownerrormessage + ") "
+        break knownerrorloop
+      }
+    }
+  }
+  return knownerrormessage
+}

logging/logging.go

@@ -88,6 +88,7 @@ func Verbosef(format string, a ...interface{}) {
 
 // Errorf prints logging if logging level >= error
 func Errorf(format string, a ...interface{}) error {
+	format = addKnownErrorMessage(a) + format
 	printf(ErrorLevel, format, a...)
 	return fmt.Errorf(format, a...)
 }

logging/logging_test.go

@@ -15,10 +15,10 @@
 package logging
 
 import (
-	"testing"
-
+	"fmt"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
+	"testing"
 )
 
 func TestLogging(t *testing.T) {
@@ -79,4 +79,25 @@ var _ = Describe("logging operations", func() {
 		currentLevel := loggingLevel
 		Expect(currentLevel).To(Equal(GetLoggingLevel()))
 	})
+
+	It("Detects a known error", func() {
+		newerror := Errorf("Testing 123", fmt.Errorf("error dialing DHCP daemon: dial unix /run/cni/dhcp.sock: connect: no such file or directory"))
+		Expect(newerror.Error()).To(ContainSubstring("Please check that the DHCP CNI daemon is running"))
+	})
+
+	It("Properly errors when an error message is not set for a pattern", func() {
+		_, err := getKnownErrorMessage("intentionally unset error pattern")
+		Expect(err).To(HaveOccurred())
+	})
+
+	It("Has a message set for each error pattern that is set", func() {
+		// If this fails, it probably means you added the error pattern, but, not the error message.
+		errpats := knownErrorPatterns()
+		for _, errorpattern := range errpats {
+			message, err := getKnownErrorMessage(errorpattern)
+			Expect(message).NotTo(HaveLen(0))
+			Expect(err).NotTo(HaveOccurred())
+		}
+	})
+
 })