Add comprehensive login page customization options

docs/FAQ.md

@@ -81,6 +81,23 @@ You can change the config file's location using the `--config` flag or
 
 The default location respects `$XDG_CONFIG_HOME`.
 
+### Login page customization
+
+You can customize the login page using the `--custom-strings` flag:
+
+```bash
+code-server --custom-strings '{"LOGIN_TITLE": "My Code Server", "WELCOME": "Welcome to my portal"}'
+```
+
+Or use a JSON file:
+```bash
+code-server --custom-strings /path/to/custom-strings.json
+```
+
+Legacy individual flags (`--app-name`, `--welcome-text`) are still supported but deprecated.
+
+For detailed customization options and examples, see the [customization guide](./customization.md).
+
 ## How do I make my keyboard shortcuts work?
 
 Many shortcuts will not work by default, since they'll be "caught" by the browser.

docs/README.md

@@ -61,6 +61,8 @@ code-server.
 We also have an in-depth [setup and
 configuration](https://coder.com/docs/code-server/latest/guide) guide.
 
+You can also customize the login page appearance - see our [customization guide](./customization.md).
+
 ## Questions?
 
 See answers to [frequently asked

docs/customization.md

@@ -0,0 +1,170 @@
+# Login Page Customization
+
+code-server allows you to customize the login page appearance and messages through a unified `--custom-strings` flag or legacy CLI arguments.
+
+## Recommended Approach: Custom Strings
+
+The `--custom-strings` flag provides a scalable way to customize any UI text by leveraging the built-in internationalization system.
+
+### Using JSON File
+
+Create a JSON file with your customizations:
+
+```json
+{
+  "WELCOME": "Welcome to {{app}} Development Portal",
+  "LOGIN_TITLE": "{{app}} Secure Access",
+  "LOGIN_BELOW": "Please authenticate to continue",
+  "PASSWORD_PLACEHOLDER": "Enter your access code",
+  "SUBMIT": "AUTHENTICATE",
+  "LOGIN_PASSWORD": "Check the config file at {{configFile}} for the password.",
+  "LOGIN_USING_ENV_PASSWORD": "Access code provided via environment variable",
+  "LOGIN_USING_HASHED_PASSWORD": "Access code configured securely",
+  "LOGIN_RATE_LIMIT": "Too many attempts. Please wait before trying again.",
+  "MISS_PASSWORD": "Access code is required",
+  "INCORRECT_PASSWORD": "Invalid access code"
+}
+```
+
+```bash
+code-server --custom-strings /path/to/custom-strings.json
+```
+
+### Using Inline JSON
+
+```bash
+code-server --custom-strings '{"WELCOME": "Welcome to My Dev Portal", "LOGIN_TITLE": "Development Access", "SUBMIT": "SIGN IN"}'
+```
+
+### Configuration File
+
+Add to your `~/.config/code-server/config.yaml`:
+
+```yaml
+bind-addr: 127.0.0.1:8080
+auth: password
+password: your-password
+custom-strings: |
+  {
+    "WELCOME": "Welcome to {{app}} Development Portal",
+    "LOGIN_TITLE": "{{app}} Secure Access",
+    "PASSWORD_PLACEHOLDER": "Enter your access code",
+    "SUBMIT": "AUTHENTICATE"
+  }
+```
+
+## Available Customization Keys
+
+| Key | Description | Default | Supports {{app}} placeholder |
+|-----|-------------|---------|------------------------------|
+| `WELCOME` | Welcome message on login page | "Welcome to {{app}}" | ✅ |
+| `LOGIN_TITLE` | Main title on login page | "{{app}} login" | ✅ |
+| `LOGIN_BELOW` | Text below the login title | "Please log in below." | ❌ |
+| `PASSWORD_PLACEHOLDER` | Password field placeholder text | "PASSWORD" | ❌ |
+| `SUBMIT` | Login button text | "SUBMIT" | ❌ |
+| `LOGIN_PASSWORD` | Message for config file password | "Check the config file at {{configFile}} for the password." | ❌ |
+| `LOGIN_USING_ENV_PASSWORD` | Message when using `$PASSWORD` env var | "Password was set from $PASSWORD." | ❌ |
+| `LOGIN_USING_HASHED_PASSWORD` | Message when using `$HASHED_PASSWORD` env var | "Password was set from $HASHED_PASSWORD." | ❌ |
+| `LOGIN_RATE_LIMIT` | Rate limiting error message | "Login rate limited!" | ❌ |
+| `MISS_PASSWORD` | Empty password error message | "Missing password" | ❌ |
+| `INCORRECT_PASSWORD` | Wrong password error message | "Incorrect password" | ❌ |
+
+## Docker Examples
+
+### Basic Docker Deployment
+
+```bash
+docker run -it --name code-server -p 127.0.0.1:8080:8080 \
+  -v "$PWD:/home/coder/project" \
+  -v "$PWD/custom-strings.json:/custom-strings.json" \
+  codercom/code-server:latest --custom-strings /custom-strings.json
+```
+
+### Corporate Branding with Inline JSON
+
+```bash
+docker run -it --name code-server -p 127.0.0.1:8080:8080 \
+  -v "$PWD:/home/coder/project" \
+  codercom/code-server:latest --custom-strings '{
+    "WELCOME": "Welcome to ACME Corporation Development Portal",
+    "LOGIN_TITLE": "ACME Dev Portal Access",
+    "LOGIN_BELOW": "Enter your corporate credentials",
+    "PASSWORD_PLACEHOLDER": "Corporate Password",
+    "SUBMIT": "SIGN IN",
+    "LOGIN_USING_ENV_PASSWORD": "Password managed by IT department"
+  }'
+```
+
+## Legacy Support (Deprecated)
+
+The following flags are still supported but deprecated. Use `--custom-strings` for new deployments:
+
+```bash
+# Deprecated - use --custom-strings instead
+code-server \
+  --app-name "My Development Server" \
+  --welcome-text "Welcome to the development environment"
+```
+
+These legacy flags will show deprecation warnings and may be removed in future versions.
+
+## Migration Guide
+
+### From Legacy Flags to Custom Strings
+
+**Old approach:**
+```bash
+code-server \
+  --app-name "Dev Portal" \
+  --welcome-text "Welcome to development"
+```
+
+**New approach:**
+```bash
+code-server --custom-strings '{
+  "WELCOME": "Welcome to development"
+}'
+```
+
+**Note:** The `--app-name` flag controls the `{{app}}` placeholder in templates. You can either:
+1. Keep using `--app-name` alongside `--custom-strings`
+2. Customize the full text without placeholders in your JSON
+
+## Benefits of Custom Strings
+
+- ✅ **Scalable**: Add any new UI strings without new CLI flags
+- ✅ **Flexible**: Supports both files and inline JSON
+- ✅ **Future-proof**: Automatically supports new UI strings as they're added
+- ✅ **Organized**: All customizations in one place
+- ✅ **Version-controlled**: JSON files can be tracked in your repository
+
+## Advanced Usage
+
+### Multi-language Support
+
+Create different JSON files for different languages:
+
+```bash
+# English
+code-server --custom-strings /config/strings-en.json
+
+# Spanish  
+code-server --custom-strings /config/strings-es.json --locale es
+```
+
+### Dynamic Customization
+
+Generate JSON dynamically in scripts:
+
+```bash
+#!/bin/bash
+COMPANY_NAME="ACME Corp"
+cat > /tmp/strings.json << EOF
+{
+  "WELCOME": "Welcome to ${COMPANY_NAME} Development Portal",
+  "LOGIN_TITLE": "${COMPANY_NAME} Access Portal"
+}
+EOF
+
+code-server --custom-strings /tmp/strings.json
+```

docs/install.md

@@ -287,6 +287,34 @@ docker run -it --name code-server -p 127.0.0.1:8080:8080 \
   codercom/code-server:latest
 ```
 
+### Customizing the login page
+
+You can customize the login page using the `--custom-strings` flag:
+
+```bash
+# Example with inline JSON customization
+docker run -it --name code-server -p 127.0.0.1:8080:8080 \
+  -v "$PWD:/home/coder/project" \
+  codercom/code-server:latest --custom-strings '{
+    "LOGIN_TITLE": "My Development Environment",
+    "WELCOME": "Welcome to your coding workspace",
+    "PASSWORD_PLACEHOLDER": "Enter your secure password",
+    "SUBMIT": "ACCESS"
+  }'
+```
+
+Or mount a JSON file:
+
+```bash
+# Example with JSON file
+docker run -it --name code-server -p 127.0.0.1:8080:8080 \
+  -v "$PWD:/home/coder/project" \
+  -v "$PWD/custom-strings.json:/config/strings.json" \
+  codercom/code-server:latest --custom-strings /config/strings.json
+```
+
+For detailed customization options, see the [customization guide](./customization.md).
+
 Our official image supports `amd64` and `arm64`. For `arm32` support, you can
 use a [community-maintained code-server
 alternative](https://hub.docker.com/r/linuxserver/code-server).

src/node/cli.ts

@@ -93,6 +93,7 @@ export interface UserProvidedArgs extends UserProvidedCodeArgs {
   "app-name"?: string
   "welcome-text"?: string
   "abs-proxy-base-path"?: string
+  "custom-strings"?: string
   /* Positional arguments. */
   _?: string[]
 }
@@ -285,16 +286,22 @@ export const options: Options<Required<UserProvidedArgs>> = {
     type: "string",
     short: "an",
     description: "The name to use in branding. Will be shown in titlebar and welcome message",
+    deprecated: true,
   },
   "welcome-text": {
     type: "string",
     short: "w",
     description: "Text to show on login page",
+    deprecated: true,
   },
   "abs-proxy-base-path": {
     type: "string",
     description: "The base path to prefix to all absproxy requests",
   },
+  "custom-strings": {
+    type: "string",
+    description: "Path to JSON file or raw JSON string with custom UI strings. Merges with default strings and supports all i18n keys.",
+  },
 }
 
 export const optionDescriptions = (opts: Partial<Options<Required<UserProvidedArgs>>> = options): string[] => {
@@ -459,6 +466,21 @@ export const parse = (
     throw new Error("--cert-key is missing")
   }
 
+  // Validate custom-strings flag
+  if (args["custom-strings"]) {
+    try {
+      // First try to parse as JSON directly
+      JSON.parse(args["custom-strings"])
+    } catch (jsonError) {
+      // If JSON parsing fails, check if it's a valid file path
+      if (!args["custom-strings"].startsWith("{") && !args["custom-strings"].startsWith("[")) {
+        // Assume it's a file path - validation will happen later when the file is read
+      } else {
+        throw error(`--custom-strings contains invalid JSON: ${jsonError instanceof Error ? jsonError.message : String(jsonError)}`)
+      }
+    }
+  }
+
   logger.debug(() => [`parsed ${opts?.configFile ? "config" : "command line"}`, field("args", redactArgs(args))])
 
   return args
@@ -593,6 +615,7 @@ export async function setDefaults(cliArgs: UserProvidedArgs, configArgs?: Config
     args["disable-proxy"] = true
   }
 
+
   const usingEnvHashedPassword = !!process.env.HASHED_PASSWORD
   if (process.env.HASHED_PASSWORD) {
     args["hashed-password"] = process.env.HASHED_PASSWORD