Expand environmental variables in sshOpts

Cargo.toml

@@ -27,6 +27,7 @@ tokio = { version = "1.9.0", features = [ "full" ] }
 toml = "0.5"
 whoami = "0.9.0"
 yn = "0.1"
+envmnt = "0.9.0"
 
 # smol_str is required by rnix, but 0.1.17 doesn't build on rustc
 # 1.45.2 (shipped in nixos-20.09); it requires rustc 1.46.0. See

src/data.rs

@@ -2,8 +2,9 @@
 //
 // SPDX-License-Identifier: MPL-2.0
 
+use envmnt::{self, ExpandOptions, ExpansionType};
 use merge::Merge;
-use serde::Deserialize;
+use serde::{Deserialize, Deserializer};
 use std::collections::HashMap;
 
 #[derive(Deserialize, Debug, Clone, Merge)]
@@ -14,7 +15,8 @@ pub struct GenericSettings {
     #[serde(
         skip_serializing_if = "Vec::is_empty",
         default,
-        rename(deserialize = "sshOpts")
+        rename(deserialize = "sshOpts"),
+        deserialize_with = "GenericSettings::de_ssh_opts"
     )]
     #[merge(strategy = merge::vec::append)]
     pub ssh_opts: Vec<String>,
@@ -30,6 +32,23 @@ pub struct GenericSettings {
     pub magic_rollback: Option<bool>,
 }
 
+impl GenericSettings {
+    fn de_ssh_opts<'de, D>(deserializer: D) -> Result<Vec<String>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let buf: Vec<String> = Vec::deserialize(deserializer)?;
+
+        let mut options = ExpandOptions::new();
+        options.expansion_type = Some(ExpansionType::UnixBrackets);
+
+        Ok(buf
+            .into_iter()
+            .map(|opt| envmnt::expand(&opt, Some(options)))
+            .collect())
+    }
+}
+
 #[derive(Deserialize, Debug, Clone)]
 pub struct NodeSettings {
     pub hostname: String,