Set the LANGUAGE environment variable in the Docker backend

docs/source/configuration/multilingual.md

@@ -9,13 +9,14 @@ myst:
 
 # Multilingual
 
-Volto provide support for Plone's Multilingual feature. You need to install Multiligual
-support in Plone (`plone.app.multilingual` add-on), that comes available by default since
-Plone 5 and can be installed in Plone's control panel.
+Volto provides support for Plone's multilingual feature through the Plone core add-on `plone.app.multilingual`.
+It is included with Plone 5 and later.
+You can enable it through the {guilabel}`Add-ons` control panel in the administrative interface.
+
 
 ## Volto configuration
 
-You need to enable multilingual in Volto's configuration object:
+You need to enable multilingual in Volto's configuration object.
 
 ```js
 import config from '@plone/volto/registry'
@@ -28,22 +29,21 @@ config.settings = {
 }
 ```
 
-Declare the language you want to support in your site in the `supportedLanguages` array,
-and which is the default language of your site.
+Declare the language you want to support in your site in the `supportedLanguages` array, and which is the default language of your site.
 
 ```{warning}
-The default language and the supported languages must match the one set in the Plone
-side, and those should be set using GenericSetup using your policy package, or
-manually via the Languages control panel, i.e. en for English, or pt-br for Portuguese (Brazil)
+The default language and the supported languages must match those set in the Plone backend.
+Those should be set either using GenericSetup using your policy package or manually via the {guilabel}`Languages` control panel.
+Examples include `en` for English, or `pt-br` for Portuguese (Brazil).
 ```
 
 ## Features
 
-Volto Multilingual features include:
+Volto multilingual includes the following features.
 
-- Language detector that detects the language preference (cookie) and redirects to the related language root folder
-- Language switcher that allows user to switch between languages
-- Add menu entries that allows to create and link a new content with the original one in one of the supported languages set in the site
-- When users use the language switcher to change language from a translated content, they are redirected to the linked content (within the same translation group)
-- Manual link two objects (Manage translations link in More menu)
-- Manual deletion of a link (unlink) between two objects (Manage translations link in More menu)
+-   language detector that detects the language preference from a cookie, and redirects to the related language root folder
+-   language switcher that allows the user to switch between languages
+-   adds menu entries that allows to create and link a new content item with the original one in one of the supported languages set in the site
+-   when users use the language switcher to change the language from a translated content, they are redirected to the linked content within the same translation group
+-   manually link two objects via the {guilabel}`Manage translations` link under the {guilabel}`More` menu
+-   manually delete a link (or unlink) between two objects ({guilabel}`Manage translations` link under the {guilabel}`More` menu)

docs/source/contributing/developing-core.md

@@ -169,7 +169,19 @@ pnpm install
 ```
 
 
-## Start the backend and Volto
+(develop-volto-start-plone-label)=
+
+## Start Plone
+
+Every time you want to run Volto for core development, you will need to create two terminal sessions, one for the {ref}`backend <develop-volto-start-the-backend-label>` and one for the {ref}`frontend <develop-volto-start-the-frontend-label>`.
+For both sessions, change your working directory to the root of your Volto clone.
+
+To stop either the backend or frontend, use {kbd}`ctrl-c`.
+
+
+(develop-volto-start-the-backend-label)=
+
+### Start the backend
 
 `````{versionadded} 18.0.0-alpha.42
 Persist backend data across Docker sessions.
@@ -184,10 +196,8 @@ It is intended only for development.
 ````
 `````
 
-Every time you want to run Volto for core development, you will need to create two terminal sessions, one for the backend and one for the frontend.
-For both sessions, change your working directory to the root of your Volto clone.
-
 In the first session, start the backend.
+You can browse to the backend running at http://localhost:8080.
 
 ```shell
 make backend-docker-start
@@ -206,19 +216,42 @@ docker volume rm volto-backend-data
 
 Then run `make backend-docker-start` again to start the backend with a clean data volume.
 ````
-
-Browse to the backend running at http://localhost:8080.
 
-In the second session, start the frontend.
+
+(develop-volto-configure-backend-language-label)=
+
+#### Configure backend language
+
+If you use the Docker image [`plone-backend`](https://github.com/plone/plone-backend), you can set its `LANGUAGE` environment variable, overriding the default of `en`, when you start it.
+
+This variable is applied only when the Plone site is created.
+If you persist data through restarts, you only need to do this once.
+Conversely, if you create a Plone site in the wrong language, you can delete the data volume, and recreate it with the correct language.
+
+You can either pass an environment variable into the make command to start the backend, or export an environment variable in your shell session and start the backend.
+
+```shell
+# pass method
+LANGUAGE=pt-br make backend-docker-start
+
+# export method
+export LANGUAGE=pt-br
+make backend-docker-start
+```
+
+
+(develop-volto-start-the-frontend-label)=
+
+## Start the frontend
+
+In the second session, start the frontend, Volto.
 
 ```shell
 pnpm start
 ```
 
 Browse to the frontend running at http://localhost:3000.
 
-To stop either the backend or frontend, use {kbd}`ctrl-c`.
-
 
 (developing-core-run-commands-for-pnpm-workspaces-label)=
 

packages/volto/Makefile

@@ -13,6 +13,9 @@ MAKEFLAGS+=--no-builtin-rules
 # Project settings (read from repo root)
 include ../../variables.mk
 
+# Allow setting the language for backend-docker-start. Default is `en`.
+LANGUAGE ?=en
+
 # Recipe snippets for reuse
 
 CHECKOUT_BASENAME="$(shell basename $(shell realpath ./))"
@@ -100,7 +103,7 @@ release-notes-copy-to-docs: ## Copy release notes into documentation
 
 .PHONY: backend-docker-start
 backend-docker-start: ## Starts a Docker-based backend for development
-	docker run -it --rm --name=backend -p 8080:8080 -v volto-backend-data:/data -e SITE=Plone -e ADDONS='$(KGS)' $(DOCKER_IMAGE)
+	docker run -it --rm --name=backend -p 8080:8080 -v volto-backend-data:/data -e SITE=Plone -e ADDONS='$(KGS)' -e LANGUAGE='$(LANGUAGE)' $(DOCKER_IMAGE)
 
 .PHONY: frontend-docker-start
 frontend-docker-start: ## Starts a Docker-based frontend for development

packages/volto/news/6231.internal

@@ -0,0 +1 @@
+Allow setting the language for `make backend-docker-start`. Default is `en`. Added usage documentation in Contributing > Develop Volto core, and reorganized it. Cleaned up Configuration > Multilingual. @stevepiercy