Log detected chia environment variables before applying them to config (#132)

When FillValuesFromEnvironment fails, the error message gives no
indication that environment variables are being read or which one caused
the issue. This is especially confusing when the user is using --set
flags and has a stale or malformed chia-prefixed env var set.

Add logging that lists each detected chia./chia__ env var before
applying them, and update the error message to direct the user to
check the listed variables.

Author: TheLastCicada

cmd/config/config.go

@@ -1,6 +1,10 @@
 package config
 
 import (
+	"os"
+	"strings"
+
+	"github.com/chia-network/go-modules/pkg/slogs"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
@@ -12,6 +16,21 @@ var (
 	retries     uint
 )
 
+// logDetectedChiaEnvVars scans the process environment for variables prefixed
+// with "chia." or "chia__" and logs each one so the user knows which env vars
+// will be applied to the config before --set flags are processed.
+func logDetectedChiaEnvVars() {
+	for _, env := range os.Environ() {
+		for _, prefix := range []string{"chia.", "chia__"} {
+			if strings.HasPrefix(env, prefix) {
+				name, _, _ := strings.Cut(env, "=")
+				slogs.Logr.Info("Detected chia environment variable that will be applied to config", "env_var", name)
+				break
+			}
+		}
+	}
+}
+
 // configCmd represents the config command
 var configCmd = &cobra.Command{
 	Use:   "config",

cmd/config/edit.go

@@ -46,9 +46,10 @@ chia-tools config edit --set full_node.port=58444 --dry-run`,
 			cfg.SetIndependentLogging()
 		}
 
+		logDetectedChiaEnvVars()
 		err = cfg.FillValuesFromEnvironment()
 		if err != nil {
-			slogs.Logr.Fatal("error filling values from environment", "error", err)
+			slogs.Logr.Fatal("error applying chia environment variables to config. Check the environment variables listed above for incorrect values", "error", err)
 		}
 
 		dryRun := viper.GetBool("dry-run")

cmd/config/generate.go

@@ -21,9 +21,10 @@ var generateCmd = &cobra.Command{
 			slogs.Logr.Fatal("error loading default config", "error", err)
 		}
 
+		logDetectedChiaEnvVars()
 		err = cfg.FillValuesFromEnvironment()
 		if err != nil {
-			slogs.Logr.Fatal("error filling values from environment", "error", err)
+			slogs.Logr.Fatal("error applying chia environment variables to config. Check the environment variables listed above for incorrect values", "error", err)
 		}
 
 		valuesToSet := viper.GetStringMapString("set")