fix: preserve env var key casing and show the env vars on the UI (#65)

Author: skylenet

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/spf13/viper v1.19.0
 	github.com/stretchr/testify v1.11.1
 	golang.org/x/sync v0.19.0
+	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
@@ -66,6 +67,5 @@ require (
 	golang.org/x/text v0.31.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 	gotest.tools/v3 v3.5.2 // indirect
 )

pkg/config/config.go

@@ -15,6 +15,7 @@ import (
 	"github.com/mitchellh/mapstructure"
 	"github.com/shirou/gopsutil/v4/cpu"
 	"github.com/spf13/viper"
+	"gopkg.in/yaml.v3"
 )
 
 const (
@@ -439,14 +440,19 @@ func Load(paths ...string) (*Config, error) {
 
 	v.SetConfigType("yaml")
 
-	// Load and merge configs in order.
+	// Load and merge configs in order, collecting expanded YAML for
+	// post-processing (Viper lowercases map keys, so we re-parse to
+	// restore original casing for environment variables).
+	rawYAMLs := make([]string, 0, len(paths))
+
 	for i, path := range paths {
 		content, err := os.ReadFile(path)
 		if err != nil {
 			return nil, fmt.Errorf("reading config file %q: %w", path, err)
 		}
 
 		expanded := os.ExpandEnv(string(content))
+		rawYAMLs = append(rawYAMLs, expanded)
 
 		if i == 0 {
 			if err := v.ReadConfig(strings.NewReader(expanded)); err != nil {
@@ -474,6 +480,8 @@ func Load(paths ...string) (*Config, error) {
 		return nil, fmt.Errorf("parsing config: %w", err)
 	}
 
+	restoreEnvironmentKeyCasing(&cfg, rawYAMLs)
+
 	cfg.applyDefaults()
 
 	return &cfg, nil
@@ -1183,3 +1191,39 @@ func bootstrapFCUDecodeHook() mapstructure.DecodeHookFuncType {
 		return data, nil
 	}
 }
+
+// rawClientConfig is a minimal struct used to re-parse environment map keys
+// with their original casing, since Viper lowercases all map keys internally.
+type rawClientConfig struct {
+	Client struct {
+		Instances []struct {
+			ID          string            `yaml:"id"`
+			Environment map[string]string `yaml:"environment"`
+		} `yaml:"instances"`
+	} `yaml:"client"`
+}
+
+// restoreEnvironmentKeyCasing re-parses the raw YAML to recover the original
+// casing of environment variable keys that Viper lowercased.
+func restoreEnvironmentKeyCasing(cfg *Config, rawYAMLs []string) {
+	envByID := make(map[string]map[string]string, len(cfg.Client.Instances))
+
+	for _, raw := range rawYAMLs {
+		var parsed rawClientConfig
+		if err := yaml.Unmarshal([]byte(raw), &parsed); err != nil {
+			continue
+		}
+
+		for _, inst := range parsed.Client.Instances {
+			if inst.Environment != nil {
+				envByID[inst.ID] = inst.Environment
+			}
+		}
+	}
+
+	for i := range cfg.Client.Instances {
+		if orig, ok := envByID[cfg.Client.Instances[i].ID]; ok {
+			cfg.Client.Instances[i].Environment = orig
+		}
+	}
+}

pkg/config/config_test.go

@@ -765,6 +765,39 @@ func TestGetBootstrapFCU(t *testing.T) {
 	}
 }
 
+func TestLoad_PreservesEnvironmentKeyCasing(t *testing.T) {
+	configContent := `
+global:
+  docker_network: test-network
+client:
+  config:
+    jwt: test-jwt
+    genesis:
+      geth: http://example.com/genesis.json
+  instances:
+    - id: test-instance
+      client: geth
+      environment:
+        MAX_REORG_DEPTH: "512"
+        SOME_lower_Mixed: "value"
+`
+	tmpDir := t.TempDir()
+	configPath := filepath.Join(tmpDir, "config.yaml")
+	require.NoError(t, os.WriteFile(configPath, []byte(configContent), 0o644))
+
+	cfg, err := Load(configPath)
+	require.NoError(t, err)
+	require.Len(t, cfg.Client.Instances, 1)
+
+	env := cfg.Client.Instances[0].Environment
+	assert.Equal(t, "512", env["MAX_REORG_DEPTH"])
+	assert.Equal(t, "value", env["SOME_lower_Mixed"])
+
+	// Verify lowercased keys are NOT present.
+	_, hasLower := env["max_reorg_depth"]
+	assert.False(t, hasLower)
+}
+
 func TestLoad_BootstrapFCU(t *testing.T) {
 	t.Run("shorthand bool true", func(t *testing.T) {
 		configContent := `

ui/src/components/run-detail/RunConfiguration.tsx

@@ -143,6 +143,27 @@ export function RunConfiguration({ instance, system, startBlock }: RunConfigurat
                 </div>
               )}
 
+              {instance.environment && Object.keys(instance.environment).length > 0 && (
+                <div>
+                  <dt className="text-xs/5 font-medium text-gray-500 dark:text-gray-400">
+                    Environment
+                  </dt>
+                  <dd className="mt-1 overflow-x-auto rounded-xs bg-gray-100 p-2 dark:bg-gray-900">
+                    <div className="flex flex-col gap-1 font-mono text-xs/5 text-gray-900 dark:text-gray-100">
+                      {Object.entries(instance.environment).map(([key, value]) => (
+                        <div key={key} className="flex items-start gap-2">
+                          <span className="break-all">
+                            <span className="text-gray-500 dark:text-gray-400">{key}=</span>
+                            {value}
+                          </span>
+                          <CopyButton text={`${key}=${value}`} />
+                        </div>
+                      ))}
+                    </div>
+                  </dd>
+                </div>
+              )}
+
               {instance.datadir && (
                 <div>
                   <dt className="flex items-center gap-2 text-xs/5 font-medium text-gray-500 dark:text-gray-400">