From 94510e60938f56d31a1fbf85524eda18f8cb8513 Mon Sep 17 00:00:00 2001
From: Pete Cornish <outofcoffee@gmail.com>
Date: Fri, 12 Apr 2024 16:29:08 +0100
Subject: [PATCH] feat: supports specification of environment variables in
 config files.

---
 cmd/up.go      | 50 ++++++++++++++++++++++++++++++++++++--------------
 docs/config.md |  4 ++++
 2 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/cmd/up.go b/cmd/up.go
index 5c1de03..dbde1e0 100644
--- a/cmd/up.go
+++ b/cmd/up.go
@@ -21,7 +21,9 @@ import (
 	"gatehill.io/imposter/engine"
 	"gatehill.io/imposter/fileutil"
 	"gatehill.io/imposter/plugin"
+	"gatehill.io/imposter/stringutil"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 	"os"
 	"os/signal"
 	"path/filepath"
@@ -55,7 +57,7 @@ var upCmd = &cobra.Command{
 If CONFIG_DIR is not specified, the current working directory is used.`,
 	Args: cobra.RangeArgs(0, 1),
 	Run: func(cmd *cobra.Command, args []string) {
-		injectExplicitEnvironment()
+		injectExplicitEnvironment(upFlags.environment)
 
 		var configDir string
 		if len(args) == 0 {
@@ -103,25 +105,13 @@ If CONFIG_DIR is not specified, the current working directory is used.`,
 			Deduplicate:     upFlags.deduplicate,
 			EnablePlugins:   upFlags.enablePlugins,
 			EnableFileCache: upFlags.enableFileCache,
-			Environment:     upFlags.environment,
+			Environment:     buildStartEnvironment(upFlags.environment),
 			DirMounts:       upFlags.dirMounts,
 		}
 		start(&lib, startOptions, configDir, upFlags.restartOnChange)
 	},
 }
 
-func injectExplicitEnvironment() {
-	for _, env := range upFlags.environment {
-		envParts := strings.Split(env, "=")
-		if len(envParts) > 1 {
-			_ = os.Setenv(envParts[0], envParts[1])
-		}
-	}
-	if upFlags.recursiveConfigScan {
-		_ = os.Setenv("IMPOSTER_CONFIG_SCAN_RECURSIVE", "true")
-	}
-}
-
 func init() {
 	upCmd.Flags().StringVarP(&upFlags.engineType, "engine-type", "t", "", "Imposter engine type (valid: docker,jvm - default \"docker\")")
 	upCmd.Flags().StringVarP(&upFlags.engineVersion, "version", "v", "", "Imposter engine version (default \"latest\")")
@@ -140,6 +130,38 @@ func init() {
 	rootCmd.AddCommand(upCmd)
 }
 
+func injectExplicitEnvironment(cliEnvArgs []string) {
+	for _, env := range cliEnvArgs {
+		envParts := strings.Split(env, "=")
+		if len(envParts) > 1 {
+			_ = os.Setenv(envParts[0], envParts[1])
+		}
+	}
+	if upFlags.recursiveConfigScan {
+		_ = os.Setenv("IMPOSTER_CONFIG_SCAN_RECURSIVE", "true")
+	}
+}
+
+func buildStartEnvironment(cliEnvArgs []string) []string {
+	env := append([]string{}, cliEnvArgs...)
+
+	// include environment variables from CLI config file, under the 'env' key, such as:
+	// ```yaml
+	// env:
+	//   IMPOSTER_FOO: bar
+	//   IMPOSTER_BAZ: qux
+	// ```
+	for k, v := range viper.GetStringMapString("env") {
+		// environment variables passed as command-line arguments take precedence
+		// over those in the config file
+		if !stringutil.ContainsPrefix(env, k+"=") {
+			env = append(env, k+"="+v)
+		}
+	}
+
+	return env
+}
+
 func start(lib *engine.EngineLibrary, startOptions engine.StartOptions, configDir string, restartOnChange bool) {
 	provider := (*lib).GetProvider(startOptions.Version)
 	mockEngine := provider.Build(configDir, startOptions)
diff --git a/docs/config.md b/docs/config.md
index 1b78b66..1e8e7fc 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -98,6 +98,10 @@ default:
   plugins:
     - store-dynamodb
     - store-redis
+
+# Map of environment variables to 
+env:
+  IMPOSTER_EXAMPLE: "some-value"
 ```
 
 ## Environment variables