Implement support for `$NIRI_CONFIG` environment variable

2 files changed, 16 insertions, 1 deletions

diff --git a/src/cli.rs b/src/cli.rs
index 52489ad0..4004a331 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -13,6 +13,9 @@ use crate::utils::version;
 #[command(subcommand_help_heading = "Subcommands")]
 pub struct Cli {
     /// Path to config file (default: `$XDG_CONFIG_HOME/niri/config.kdl`).
+    ///
+    /// This can also be set with the `NIRI_CONFIG` environment variable. If both are set, the
+    /// command line argument takes precedence.
     #[arg(short, long)]
     pub config: Option<PathBuf>,
     /// Import environment globally to systemd and D-Bus, run D-Bus services.
@@ -43,6 +46,9 @@ pub enum Sub {
     /// Validate the config file.
     Validate {
         /// Path to config file (default: `$XDG_CONFIG_HOME/niri/config.kdl`).
+        ///
+        /// This can also be set with the `NIRI_CONFIG` environment variable. If both are set, the
+        /// command line argument takes precedence.
         #[arg(short, long)]
         config: Option<PathBuf>,
     },
diff --git a/src/main.rs b/src/main.rs
index fb399f3a..ad201b2d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -91,6 +91,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                 tracy_client::Client::start();
 
                 let path = config
+                    .or_else(env_config_path)
                     .or_else(default_config_path)
                     .expect("error getting config path");
                 Config::load(&path)?;
@@ -113,7 +114,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     // Load the config.
     let mut config_created = false;
-    let path = cli.config.or_else(|| {
+    let path = cli.config.or_else(env_config_path);
+    env::remove_var("NIRI_CONFIG");
+    let path = path.or_else(|| {
         let default_path = default_config_path()?;
         let default_parent = default_path.parent().unwrap();
 
@@ -315,6 +318,12 @@ fn import_environment() {
     }
 }
 
+fn env_config_path() -> Option<PathBuf> {
+    env::var_os("NIRI_CONFIG")
+        .filter(|x| !x.is_empty())
+        .map(PathBuf::from)
+}
+
 fn default_config_path() -> Option<PathBuf> {
     let Some(dirs) = ProjectDirs::from("", "", "niri") else {
         warn!("error retrieving home directory");