[BRANDING] parse FORGEJO__* in the container environment

Add the FORGEJO__ prefix as equivalent to GITEA__ when interpreted by
environment-to-ini. It is used when running the Forgejo container like
so:

  docker run --name forgejo -e FORGEJO__security__INSTALL_LOCK=true \
             -d codeberg.org/forgejo/forgejo:1.18

Signed-off-by: Earl Warren <contact@earl-warren.org>

.woodpecker/testing-amd64.yml

@@ -78,6 +78,14 @@ pipeline:
     commands:
     - ./build/test-env-prepare.sh
 
+  environment-to-ini:
+    image: *golang_image
+    environment:
+      GOPROXY_OVERRIDE: *goproxy_override
+    commands:
+      - *goproxy_setup
+      - go test contrib/environment-to-ini/environment-to-ini.go contrib/environment-to-ini/environment-to-ini_test.go
+
   build:
     image: *test_image
     environment:

contrib/environment-to-ini/environment-to-ini.go

@@ -1,3 +1,4 @@
+// Copyright 2023 The Forgejo Authors. All rights reserved.
 // Copyright 2019 The Gitea Authors. All rights reserved.
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
@@ -19,17 +20,17 @@ import (
 )
 
 // EnvironmentPrefix environment variables prefixed with this represent ini values to write
-const EnvironmentPrefix = "GITEA"
+const prefixRegexpString = "^(FORGEJO|GITEA)"
 
 func main() {
 	app := cli.NewApp()
 	app.Name = "environment-to-ini"
 	app.Usage = "Use provided environment to update configuration ini"
-	app.Description = `As a helper to allow docker users to update the gitea configuration
+	app.Description = `As a helper to allow docker users to update the forgejo configuration
 	through the environment, this command allows environment variables to
 	be mapped to values in the ini.
 
-	Environment variables of the form "GITEA__SECTION_NAME__KEY_NAME"
+	Environment variables of the form "FORGEJO__SECTION_NAME__KEY_NAME"
 	will be mapped to the ini section "[section_name]" and the key
 	"KEY_NAME" with the value as provided.
 
@@ -47,9 +48,8 @@ func main() {
 		...
 		"""
 
-	You would set the environment variables: "GITEA__LOG_0x2E_CONSOLE__COLORIZE=false"
-	and "GITEA__LOG_0x2E_CONSOLE__STDERR=false". Other examples can be found
-	on the configuration cheat sheet.`
+	You would set the environment variables: "FORGEJO__LOG_0x2E_CONSOLE__COLORIZE=false"
+	and "FORGEJO__LOG_0x2E_CONSOLE__STDERR=false".`
 	app.Flags = []cli.Flag{
 		cli.StringFlag{
 			Name:  "custom-path, C",
@@ -77,7 +77,7 @@ func main() {
 		},
 		cli.StringFlag{
 			Name:  "prefix, p",
-			Value: EnvironmentPrefix,
+			Value: prefixRegexpString,
 			Usage: "Environment prefix to look for - will be suffixed by __ (2 underscores)",
 		},
 	}
@@ -90,6 +90,19 @@ func main() {
 	}
 }
 
+func splitEnvironmentVariable(prefixRegexp *regexp.Regexp, kv string) (string, string) {
+	idx := strings.IndexByte(kv, '=')
+	if idx < 0 {
+		return "", ""
+	}
+	k := kv[:idx]
+	loc := prefixRegexp.FindStringIndex(k)
+	if loc == nil {
+		return "", ""
+	}
+	return k[loc[1]:], kv[idx+1:]
+}
+
 func runEnvironmentToIni(c *cli.Context) error {
 	providedCustom := c.String("custom-path")
 	providedConf := c.String("config")
@@ -112,19 +125,13 @@ func runEnvironmentToIni(c *cli.Context) error {
 
 	changed := false
 
-	prefix := c.String("prefix") + "__"
+	prefixRegexp := regexp.MustCompile(c.String("prefix") + "__")
 
 	for _, kv := range os.Environ() {
-		idx := strings.IndexByte(kv, '=')
-		if idx < 0 {
+		eKey, value := splitEnvironmentVariable(prefixRegexp, kv)
+		if eKey == "" {
 			continue
 		}
-		eKey := kv[:idx]
-		value := kv[idx+1:]
-		if !strings.HasPrefix(eKey, prefix) {
-			continue
-		}
-		eKey = eKey[len(prefix):]
 		sectionName, keyName := DecodeSectionKey(eKey)
 		if len(keyName) == 0 {
 			continue
@@ -164,14 +171,11 @@ func runEnvironmentToIni(c *cli.Context) error {
 	}
 	if c.Bool("clear") {
 		for _, kv := range os.Environ() {
-			idx := strings.IndexByte(kv, '=')
-			if idx < 0 {
+			eKey, _ := splitEnvironmentVariable(prefixRegexp, kv)
+			if eKey == "" {
 				continue
 			}
-			eKey := kv[:idx]
-			if strings.HasPrefix(eKey, prefix) {
-				_ = os.Unsetenv(eKey)
-			}
+			_ = os.Unsetenv(eKey)
 		}
 	}
 	return nil

contrib/environment-to-ini/environment-to-ini_test.go

@@ -0,0 +1,21 @@
+// Copyright 2023 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package main
+
+import (
+	"regexp"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_splitEnvironmentVariable(t *testing.T) {
+	prefixRegexp := regexp.MustCompile(prefixRegexpString + "__")
+	k, v := splitEnvironmentVariable(prefixRegexp, "FORGEJO__KEY=VALUE")
+	assert.Equal(t, k, "KEY")
+	assert.Equal(t, v, "VALUE")
+	k, v = splitEnvironmentVariable(prefixRegexp, "nothing=interesting")
+	assert.Equal(t, k, "")
+	assert.Equal(t, v, "")
+}