From a8d39ded979710873c0dd980301d227eac486fbf Mon Sep 17 00:00:00 2001
From: Joe Afflerbach <joe.afflerbach@avenga.com>
Date: Tue, 5 Jul 2022 12:12:54 +0200
Subject: [PATCH] Start over if `environment` is set via `settings`.

---
 config/configload/load.go       | 11 ++++++
 config/settings.go              |  2 ++
 server/http_integration_test.go | 64 ++++++++++++++++++++++++++++++++-
 3 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/config/configload/load.go b/config/configload/load.go
index 5dd5aadc8..634473856 100644
--- a/config/configload/load.go
+++ b/config/configload/load.go
@@ -145,6 +145,17 @@ func LoadFiles(filesList []string, env string) (*config.Couper, error) {
 		return nil, err
 	}
 
+	if env == "" {
+		settingsBlock := mergeSettings(parsedBodies)
+		settings := &config.Settings{}
+		if diags := gohcl.DecodeBody(settingsBlock.Body, nil, settings); diags.HasErrors() {
+			return nil, diags
+		}
+		if settings.Environment != "" {
+			return LoadFiles(filesList, settings.Environment)
+		}
+	}
+
 	defaultsBlock, err := mergeDefaults(parsedBodies)
 	if err != nil {
 		return nil, err
diff --git a/config/settings.go b/config/settings.go
index 105c81d33..0fedf1713 100644
--- a/config/settings.go
+++ b/config/settings.go
@@ -53,6 +53,7 @@ const otelCollectorEndpoint = "localhost:4317"
 // DefaultSettings defines the <DefaultSettings> object.
 var DefaultSettings = Settings{
 	DefaultPort:              8080,
+	Environment:              "",
 	HealthPath:               "/healthz",
 	LogFormat:                "common",
 	LogLevel:                 "info",
@@ -81,6 +82,7 @@ type Settings struct {
 	CAFile                    string   `hcl:"ca_file,optional"`
 	AcceptForwardedURL        []string `hcl:"accept_forwarded_url,optional"`
 	DefaultPort               int      `hcl:"default_port,optional"`
+	Environment               string   `hcl:"environment,optional"`
 	HealthPath                string   `hcl:"health_path,optional"`
 	LogFormat                 string   `hcl:"log_format,optional"`
 	LogLevel                  string   `hcl:"log_level,optional"`
diff --git a/server/http_integration_test.go b/server/http_integration_test.go
index 5a28bc6c4..18b6589e4 100644
--- a/server/http_integration_test.go
+++ b/server/http_integration_test.go
@@ -513,7 +513,6 @@ func TestHTTPServer_EnvVars(t *testing.T) {
 	if res.StatusCode != http.StatusUnauthorized {
 		t.Errorf("expected 401, got %d", res.StatusCode)
 	}
-
 }
 
 func TestHTTPServer_XFHHeader(t *testing.T) {
@@ -5456,3 +5455,66 @@ func TestWildcardURLAttribute(t *testing.T) {
 		})
 	}
 }
+
+func TestEnvironmentSetting(t *testing.T) {
+	helper := test.New(t)
+	tests := []struct {
+		env string
+	}{
+		{""},
+		{"foo"},
+		{"bar"},
+	}
+
+	template := `
+	  server {
+	    endpoint "/" {
+	      response {
+	        environment "foo" {
+	          headers = { X-Env: "foo" }
+	        }
+	        environment "bar" {
+	          headers = { X-Env: "bar" }
+	        }
+	      }
+	    }
+	  }
+	  settings {
+	    environment = "%s"
+	  }
+	`
+
+	file, err := os.CreateTemp("", "tmpfile-")
+	helper.Must(err)
+	defer file.Close()
+	defer os.Remove(file.Name())
+
+	client := newClient()
+	for _, tt := range tests {
+		t.Run(tt.env, func(subT *testing.T) {
+			config := []byte(fmt.Sprintf(template, tt.env))
+			err := os.Truncate(file.Name(), 0)
+			helper.Must(err)
+			_, err = file.Seek(0, 0)
+			helper.Must(err)
+			_, err = file.Write(config)
+			helper.Must(err)
+
+			couperConfig, err := configload.LoadFile(file.Name(), "")
+			helper.Must(err)
+
+			shutdown, _ := newCouperWithConfig(couperConfig, helper)
+			defer shutdown()
+
+			req, err := http.NewRequest(http.MethodGet, "http://localhost:8080/", nil)
+			helper.Must(err)
+
+			res, err := client.Do(req)
+			helper.Must(err)
+
+			if header := res.Header.Get("X-Env"); header != tt.env {
+				subT.Errorf("Unexpected header:\n\tWant: %q\n\tGot:  %q", tt.env, header)
+			}
+		})
+	}
+}