Add cmd to allow generalised mapping of environment variables to Gitea Ini

cmd/environment_to_ini.go

@@ -0,0 +1,145 @@
+// 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.
+
+package cmd
+
+import (
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"github.com/Unknwon/com"
+	"github.com/urfave/cli"
+	ini "gopkg.in/ini.v1"
+)
+
+// EnvironmentPrefix environment variables prefixed with this represent ini values to write
+const EnvironmentPrefix = "GITEA__"
+
+// CmdEnvironmentToIni represents the command to use a provided environment to update the configuration ini
+var CmdEnvironmentToIni = cli.Command{
+	Name:   "environment-to-ini",
+	Usage:  "Use provided environment to update configuration ini",
+	Action: runEnvironmentToIni,
+	Flags: []cli.Flag{
+		cli.StringFlag{
+			Name:  "out, o",
+			Value: "",
+			Usage: "Destination file to write to",
+		},
+	},
+}
+
+func runEnvironmentToIni(c *cli.Context) error {
+	cfg := ini.Empty()
+	if com.IsFile(setting.CustomConf) {
+		if err := cfg.Append(setting.CustomConf); err != nil {
+			log.Fatal("Failed to load custom conf '%s': %v", setting.CustomConf, err)
+		}
+	} else {
+		log.Warn("Custom config '%s' not found, ignore this if you're running first time", setting.CustomConf)
+	}
+	cfg.NameMapper = ini.AllCapsUnderscore
+
+	for _, kv := range os.Environ() {
+		idx := strings.IndexByte(kv, '=')
+		if idx < 0 {
+			continue
+		}
+		eKey := kv[:idx]
+		value := kv[idx+1:]
+		if !strings.HasPrefix(eKey, EnvironmentPrefix) {
+			continue
+		}
+		sectionName, keyName := DecodeSectionKey(eKey)
+		if len(keyName) == 0 {
+			continue
+		}
+		section, err := cfg.GetSection(sectionName)
+		if err != nil {
+			section, err = cfg.NewSection(sectionName)
+			if err != nil {
+				log.Error("Error creating section: %s : %v", sectionName, err)
+				continue
+			}
+		}
+		key := section.Key(keyName)
+		if key == nil {
+			key, err = section.NewKey(keyName, value)
+			if err != nil {
+				log.Error("Error creating key: %s in section: %s with value: %s : %v", keyName, sectionName, value, err)
+				continue
+			}
+		}
+		key.SetValue(value)
+	}
+	destination := c.String("out")
+	if len(destination) == 0 {
+		destination = setting.CustomConf
+	}
+	err := cfg.SaveTo(destination)
+	return err
+}
+
+const escapeRegexpString = "_0[xX](([0-9a-fA-F][0-9a-fA-F])+)_"
+
+var escapeRegex = regexp.MustCompile(escapeRegexpString)
+
+// DecodeSectionKey will decode a portable string encoded Section__Key pair
+// Portable strings are considered to be of the form [A-Z0-9_]*
+// We will encode a disallowed value as the UTF8 byte string preceded by _0X and
+// followed by _. E.g. _0X2C_ for a '-' and _0X2E_ for '.'
+// Section and Key are separated by a plain '__'.
+// The entire section can be encoded as a UTF8 byte string
+func DecodeSectionKey(encoded string) (string, string) {
+	section := ""
+	key := ""
+
+	inKey := false
+	last := 0
+	escapeStringIndices := escapeRegex.FindAllStringIndex(encoded, -1)
+	for _, unescapeIdx := range escapeStringIndices {
+		preceding := encoded[last:unescapeIdx[0]]
+		if !inKey {
+			if splitter := strings.Index(preceding, "__"); splitter > -1 {
+				section += preceding[:splitter]
+				inKey = true
+				key += preceding[splitter+2:]
+			} else {
+				section += preceding
+			}
+		} else {
+			key += preceding
+		}
+		toDecode := encoded[unescapeIdx[0]+3 : unescapeIdx[1]-1]
+		decodedBytes := make([]byte, len(toDecode)/2)
+		for i := 0; i < len(toDecode)/2; i++ {
+			// Can ignore error here as we know these should be hexadecimal from the regexp
+			byteInt, _ := strconv.ParseInt(toDecode[2*i:2*i+2], 16, 0)
+			decodedBytes[i] = byte(byteInt)
+		}
+		if inKey {
+			key += string(decodedBytes)
+		} else {
+			section += string(decodedBytes)
+		}
+		last = unescapeIdx[1]
+	}
+	remaining := encoded[last:]
+	if !inKey {
+		if splitter := strings.Index(remaining, "__"); splitter > -1 {
+			section += remaining[:splitter]
+			inKey = true
+			key += remaining[splitter+2:]
+		} else {
+			section += remaining
+		}
+	} else {
+		key += remaining
+	}
+	return section, key
+}

cmd/environment_to_ini_test.go

@@ -0,0 +1,64 @@
+// 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.
+
+package cmd
+
+import "testing"
+
+func TestDecodeSectionKey(t *testing.T) {
+	tests := []struct {
+		name    string
+		encoded string
+		section string
+		key     string
+	}{
+		{
+			name:    "Simple",
+			encoded: "Section__Key",
+			section: "Section",
+			key:     "Key",
+		},
+		{
+			name:    "LessSimple",
+			encoded: "Section_SubSection__Key_SubKey",
+			section: "Section_SubSection",
+			key:     "Key_SubKey",
+		},
+		{
+			name:    "OneDotOneDash",
+			encoded: "Section_0X2E_SubSection__Key_0X2D_SubKey",
+			section: "Section.SubSection",
+			key:     "Key-SubKey",
+		},
+		{
+			name:    "OneDotOneEncodedOneDash",
+			encoded: "Section_0X2E_0X2E_Sub_0X2D_Section__Key_0X2D_SubKey",
+			section: "Section.0X2E_Sub-Section",
+			key:     "Key-SubKey",
+		},
+		{
+			name:    "EncodedUnderscore",
+			encoded: "Section__0X5F_0X2E_Sub_0X2D_Section__Key_0X2D__0X2D_SubKey",
+			section: "Section__0X2E_Sub-Section",
+			key:     "Key--SubKey",
+		},
+		{
+			name:    "EncodedUtf8",
+			encoded: "Section__0XE280A6_Sub_0X2D_Section__Key_0X2D__0X2D_SubKey",
+			section: "Section_…Sub-Section",
+			key:     "Key--SubKey",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotSection, gotKey := DecodeSectionKey(tt.encoded)
+			if gotSection != tt.section {
+				t.Errorf("DecodeSectionKey() gotSection = %v, want %v", gotSection, tt.section)
+			}
+			if gotKey != tt.key {
+				t.Errorf("DecodeSectionKey() gotKey = %v, want %v", gotKey, tt.key)
+			}
+		})
+	}
+}

docker/root/etc/s6/gitea/setup

@@ -43,6 +43,8 @@ if [ ! -f ${GITEA_CUSTOM}/conf/app.ini ]; then
     SECRET_KEY=${SECRET_KEY:-""} \
     envsubst < /etc/templates/app.ini > ${GITEA_CUSTOM}/conf/app.ini
 
+    /app/gitea/gitea environment-to-ini -c ${GITEA_CUSTOM}/conf/app.ini
+
     chown ${USER}:git ${GITEA_CUSTOM}/conf/app.ini
 fi
 

docs/content/doc/installation/with-docker.en-us.md

@@ -261,6 +261,10 @@ You can configure some of Gitea's settings via environment variables:
 * `USER_UID`: **1000**: The UID (Unix user ID) of the user that runs Gitea within the container. Match this to the UID of the owner of the `/data` volume if using host volumes (this is not necessary with named volumes).
 * `USER_GID`: **1000**: The GID (Unix group ID) of the user that runs Gitea within the container. Match this to the GID of the owner of the `/data` volume if using host volumes (this is not necessary with named volumes).
 
+Any other configuration value can be set using environment variables
+of the form: `GITEA__SECTION_NAME__KEY_NAME`. See the
+`environment-to-ini` command for more information.
+
 # Customization
 
 Customization files described [here](https://docs.gitea.io/en-us/customizing-gitea/) should

docs/content/doc/usage/command-line.en-us.md

@@ -281,3 +281,22 @@ provided key. You should also set the value
 NB: opensshd requires the gitea program to be owned by root and not
 writable by group or others. The program must be specified by an absolute
 path.
+
+#### environment-to-ini
+
+As a helper to allow docker users to update the gitea 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`
+will be mapped to the ini section `[section_name]` and the key 
+`KEY_NAME` with the value as provided.
+
+Environment variables are usually restricted to a reduced character
+set `0-9A-Z_` - in order to allow the setting of sections with
+characters outside of that set, they should be escaped as following:
+`_0X2E_` for `.`. The entire section and key names can be escaped as
+a UTF8 byte string if necessary.
+
+- Options:
+    - `--out name`, `-o name`: Name of the adjusted ini file to be created. Optional. (default: The gitea conf file will be changed in place).

main.go

@@ -68,6 +68,7 @@ arguments - which can alternatively be run by running the subcommand web.`
 		cmd.CmdMigrate,
 		cmd.CmdKeys,
 		cmd.CmdConvert,
+		cmd.CmdEnvironmentToIni,
 	}
 	// Now adjust these commands to add our global configuration options