feat: default node version to .nvmrc when available

docs/content/users/extend/customization-extendibility.md

@@ -32,6 +32,7 @@ If you need to create a service configuration for your project, see [Defining Ad
 There are many ways to deploy Node.js in any project, so DDEV tries to let you set up any possibility you can come up with.
 
 * You can choose any Node.js version you want (including minor and older versions) in `.ddev/config.yaml` with [`nodejs_version`](../configuration/config.md#nodejs_version).
+* If you have a `.nvmrc` file in the root of your project, DDEV will use this as the default node version if you don't include `nodejs_version` in your `config.yaml` file.
 * [`ddev nvm`](../usage/commands.md#nvm) gives you the full capabilities of [Node Version Manager](https://github.com/nvm-sh/nvm).
 * [`ddev npm`](../usage/commands.md#npm) and [`ddev yarn`](../usage/commands.md#yarn) provide shortcuts to the `npm` and `yarn` commands inside the container, and their caches are persistent.
 * You can run Node.js daemons using [`web_extra_daemons`](#running-extra-daemons-in-the-web-container).

docs/content/users/usage/cli.md

@@ -36,6 +36,8 @@ Type `ddev` or `ddev -h` in a terminal window to see the available DDEV [command
 
 `node`, `nodejs`, `npm`, `nvm` and `yarn` are preinstalled in the web container. You can configure the default value of the installed Node.js version with the [`nodejs_version`](../configuration/config.md#nodejs_version) option in `.ddev/config.yaml` or with `ddev config --nodejs_version`. You can also override that with any value using the built-in `nvm` in the web container or with [`ddev nvm`](../usage/commands.md#nvm), for example `ddev nvm install 6`. There is also a [`ddev yarn`](../usage/commands.md#yarn) command. (Note that since `nodejs_version` configuration can now specify any `node` version, including patch versions, it's preferred to using the less robust `ddev nvm` way of specifying the `node` version.)
 
+If you have a `.nvmrc` file in the root of your project, DDEV will use this as the default node version if you don't include `nodejs_version` in your `config.yaml` file.
+
 ## More Bundled Tools
 
 In addition to the [*commands*](../usage/commands.md) listed above, there are lots of tools included inside the containers:

pkg/ddevapp/config.go

@@ -31,6 +31,9 @@ import (
 // Regexp pattern to determine if a hostname is valid per RFC 1123.
 var hostRegex = regexp.MustCompile(`^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])$`)
 
+// Default NodeJS version, either from .nvmrc of the constant value defined by DDEV itself.
+var nodeJsDefault string
+
 // init() is for testing situations only, allowing us to override the default webserver type
 // or caching behavior
 func init() {
@@ -84,7 +87,7 @@ func NewApp(appRoot string, includeOverrides bool) (*DdevApp, error) {
 	app.Type = nodeps.AppTypeNone
 	app.PHPVersion = nodeps.PHPDefault
 	app.ComposerVersion = nodeps.ComposerDefault
-	app.NodeJSVersion = nodeps.NodeJSDefault
+	app.NodeJSVersion = app.getNodeJSDefault()
 	app.WebserverType = nodeps.WebserverDefault
 	app.SetPerformanceMode(nodeps.PerformanceModeDefault)
 
@@ -209,7 +212,7 @@ func (app *DdevApp) WriteConfig() error {
 		appcopy.DefaultContainerTimeout = ""
 	}
 
-	if appcopy.NodeJSVersion == nodeps.NodeJSDefault {
+	if appcopy.NodeJSVersion == app.getNodeJSDefault() {
 		appcopy.NodeJSVersion = ""
 	}
 
@@ -949,7 +952,7 @@ func (app *DdevApp) RenderComposeYAML() (string, error) {
 
 	extraWebContent := "\nRUN mkdir -p /home/$username && chown $username /home/$username && chmod 600 /home/$username/.pgpass"
 	extraWebContent = extraWebContent + "\nENV NVM_DIR=/home/$username/.nvm"
-	if app.NodeJSVersion != nodeps.NodeJSDefault {
+	if app.NodeJSVersion != app.getNodeJSDefault() {
 		extraWebContent = extraWebContent + "\nRUN npm install -g n"
 		extraWebContent = extraWebContent + fmt.Sprintf("\nRUN n install %s && ln -sf /usr/local/bin/node /usr/local/bin/nodejs", app.NodeJSVersion)
 	}
@@ -1443,3 +1446,28 @@ func validateHookYAML(source []byte) error {
 
 	return nil
 }
+
+func (app *DdevApp) getNodeJSDefault() string {
+	if nodeJsDefault != "" {
+		return nodeJsDefault
+	}
+	nvmrcPath := filepath.Join(app.GetAppRoot(), ".nvmrc")
+	if fileutil.FileExists(nvmrcPath) && fileutil.FileIsReadable(nvmrcPath) {
+		versionRaw, err := fileutil.ReadFileIntoString(nvmrcPath)
+		if err == nil {
+			version := strings.TrimSpace(versionRaw)
+			if ok, err := regexp.MatchString(`^[0-9]+(\.[0-9]+(\.[0-9]+)?)?$`, version); ok && err == nil {
+				nodeJsDefault = version
+				return version
+			} else {
+				// emit a warning and fall back to the const default.
+				util.Warning("Problem getting node version from .nvmrc file, falling back to default.")
+			}
+		} else {
+			// emit a warning and fall back to the const default.
+			util.Warning("Error reading .nvmrc file, falling back to default. Error: %v", err)
+		}
+	}
+	nodeJsDefault = nodeps.NodeJSDefault
+	return nodeps.NodeJSDefault
+}

pkg/nodeps/values.go

@@ -1,9 +1,10 @@
 package nodeps
 
 import (
-	"github.com/maruel/natural"
 	"sort"
 
+	"github.com/maruel/natural"
+
 	"github.com/ddev/ddev/pkg/config/types"
 )