flake.nix

@@ -81,7 +81,7 @@
     };
 
     devShell = pkgs.mkShell {
-      RUST_SRC_PATH = "${pkgs.rustPlatform.rustcSrc}/library";
+      RUST_SRC_PATH = "${pkgs.rustPlatform.rustLibSrc}";
       NIX_PATH = "nixpkgs=${pkgs.path}";
 
       inputsFrom = [ defaultPackage packages.manualFast ];

src/error.rs

@@ -6,7 +6,7 @@ use std::process::ExitStatus;
 use snafu::{Backtrace, Snafu};
 use validator::ValidationErrors;
 
-use crate::nix::{key, Profile, StorePath};
+use crate::nix::{key, NodeName, Profile, StorePath};
 
 pub type ColmenaResult<T> = Result<T, ColmenaError>;
 
@@ -76,6 +76,18 @@ pub enum ColmenaError {
     #[snafu(display("Filter rule cannot be empty"))]
     EmptyFilterRule,
 
+    #[snafu(display(
+        "Alias \"{}\" is already taken by {} \"{}\"",
+        what.as_str(),
+        if *is_node_name { "node name" } else { "alias" },
+        with.as_str(),
+    ))]
+    DuplicateAlias {
+        what: NodeName,
+        is_node_name: bool,
+        with: NodeName,
+    },
+
     #[snafu(display("Deployment already executed"))]
     DeploymentAlreadyExecuted,
 

src/nix/hive/mod.rs

@@ -3,7 +3,7 @@ mod assets;
 #[cfg(test)]
 mod tests;
 
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::convert::AsRef;
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
@@ -14,6 +14,7 @@ use tokio::sync::OnceCell;
 use validator::Validate;
 
 use super::deployment::TargetNode;
+use super::node_filter::{NeedsEval, PartialNodeConfig};
 use super::{
     Flake, MetaConfig, NixExpression, NixFlags, NodeConfig, NodeFilter, NodeName,
     ProfileDerivation, RegistryConfig, SerializedNixExpression, StorePath,
@@ -260,39 +261,66 @@ impl Hive {
         ssh_config: Option<PathBuf>,
         ssh_only: bool,
     ) -> ColmenaResult<HashMap<NodeName, TargetNode>> {
-        let mut node_configs = None;
-
         log::info!("Enumerating systems...");
         let registry = self.get_registry_config().await?;
 
         log::info!("Enumerating nodes...");
-
         let all_nodes = self.node_names().await?;
+
+        // try to quickly evaluate the filter without any data to see if it's trivial to evaluate
+        let filter_trivial = filter.as_ref().and_then(|filter| filter.try_eval_trivial());
+
         let selected_nodes = match filter {
-            Some(filter) => {
-                if filter.has_node_config_rules() {
-                    log::debug!("Retrieving deployment info for all nodes...");
+            Some(filter) if filter_trivial.is_none() => {
+                log::debug!("Retrieving deployment info for all nodes...");
 
-                    let all_node_configs = self.deployment_info().await?;
-                    let filtered = filter
-                        .filter_node_configs(all_node_configs.iter())
-                        .into_iter()
-                        .collect();
+                let needs_eval = filter.needs_eval();
 
-                    node_configs = Some(all_node_configs);
+                let all_node_configs = self.deployment_info_partial(needs_eval).await?;
 
-                    filtered
-                } else {
-                    filter.filter_node_names(&all_nodes)?.into_iter().collect()
+                // Check for collisions between node names and aliases
+                // Returns error if:
+                // - A node has an alias matching another node's name
+                // - A node has an alias matching its own name
+                // - A node has an alias already used by another node
+                if needs_eval.aliases {
+                    let mut taken_aliases = HashSet::new();
+                    for (name, config) in all_node_configs.iter() {
+                        for alias in config.aliases.as_ref().unwrap().iter() {
+                            let overlaps_this = alias == name;
+                            let overlaps_names = all_node_configs.contains_key(alias);
+                            let overlaps_aliases = !taken_aliases.insert(alias.clone());
+                            if overlaps_this || overlaps_names || overlaps_aliases {
+                                return Err(ColmenaError::DuplicateAlias {
+                                    what: alias.clone(),
+                                    is_node_name: overlaps_this || overlaps_names,
+                                    with: name.clone(),
+                                });
+                            }
+                        }
+                    }
                 }
+
+                let filtered = filter
+                    .filter_nodes(all_node_configs.iter())
+                    .into_iter()
+                    .collect();
+
+                filtered
             }
-            None => all_nodes.clone(),
+            _ => match filter_trivial {
+                // Filter is known to always evaluate to no nodes
+                Some(false) => vec![],
+                _ => all_nodes.clone(),
+            },
         };
 
         let n_selected = selected_nodes.len();
+        log::debug!("Filtered {n_selected} node names for deployment");
 
-        let mut node_configs = if let Some(configs) = node_configs {
-            configs.into_iter().filter(|(name, _)| selected_nodes.contains(name)).collect()
+        let mut node_configs = if n_selected == all_nodes.len() {
+            log::debug!("Retrieving deployment info for all nodes...");
+            self.deployment_info().await?
         } else {
             log::debug!("Retrieving deployment info for selected nodes...");
             self.deployment_info_selected(&selected_nodes).await?
@@ -396,6 +424,34 @@ impl Hive {
         Ok(configs)
     }
 
+    pub async fn deployment_info_partial(
+        &self,
+        needs_eval: NeedsEval,
+    ) -> ColmenaResult<HashMap<NodeName, PartialNodeConfig>> {
+        if !needs_eval.any() {
+            // Need just the un-aliased names
+            return Ok(self
+                .node_names()
+                .await?
+                .into_iter()
+                .map(|name| (name, PartialNodeConfig::default()))
+                .collect());
+        }
+
+        let expr = format!(
+            "(mapAttrs (name: attrs: {{ inherit (attrs) {} {}; }}) hive.deploymentConfig)",
+            needs_eval.aliases.then_some("aliases").unwrap_or_default(),
+            needs_eval.tags.then_some("tags").unwrap_or_default(),
+        );
+        let configs: HashMap<NodeName, PartialNodeConfig> = self
+            .nix_instantiate(&expr)
+            .eval_with_builders()
+            .await?
+            .capture_json()
+            .await?;
+        Ok(configs)
+    }
+
     /// Retrieve deployment info for a single node.
     #[cfg_attr(not(target_os = "linux"), allow(dead_code))]
     pub async fn deployment_info_single(

src/nix/hive/options.nix

@@ -93,6 +93,7 @@ with builtins; rec {
   # Largely compatible with NixOps/Morph.
   deploymentOptions = { name, lib, ... }: let
     inherit (lib) types;
+    mdDoc = lib.mdDoc or lib.id;
   in {
     options = {
       deployment = {
@@ -178,6 +179,15 @@ with builtins; rec {
           type = types.listOf types.str;
           default = [];
         };
+        aliases = lib.mkOption {
+          description = ''
+            A list of aliases for the node.
+
+            Can be used to select a node with another name.
+          '';
+          type = types.listOf types.str;
+          default = [];
+        };
         keys = lib.mkOption {
           description = ''
             A set of secrets to be deployed to the node.

src/nix/mod.rs

@@ -75,6 +75,8 @@ pub struct NodeConfig {
 
     tags: Vec<String>,
 
+    aliases: Vec<NodeName>,
+
     #[serde(rename = "replaceUnknownProfiles")]
     replace_unknown_profiles: bool,
 

src/nix/node_filter.rs

@@ -7,6 +7,7 @@ use std::str::FromStr;
 
 use clap::Args;
 use glob::Pattern as GlobPattern;
+use serde::Deserialize;
 
 use super::{ColmenaError, ColmenaResult, NodeConfig, NodeName};
 
@@ -28,6 +29,53 @@ The list is comma-separated and globs are supported. To match tags, prepend the
     pub on: Option<NodeFilter>,
 }
 
+/// Which fields need to be evaluated
+/// in order to execute the node filter.
+#[derive(Clone, Copy, Debug, Default)]
+pub struct NeedsEval {
+    /// Need to evaluate deployment.aliases of all nodes.
+    pub aliases: bool,
+    /// Need to evaluate deployment.tags of all nodes.
+    pub tags: bool,
+}
+
+impl NeedsEval {
+    pub fn any(&self) -> bool {
+        self.aliases || self.tags
+    }
+}
+
+impl std::ops::BitOr for NeedsEval {
+    type Output = Self;
+    fn bitor(self, rhs: Self) -> Self::Output {
+        Self {
+            aliases: self.aliases || rhs.aliases,
+            tags: self.tags || rhs.tags,
+        }
+    }
+}
+
+impl std::ops::BitOrAssign for NeedsEval {
+    fn bitor_assign(&mut self, rhs: Self) {
+        *self = *self | rhs;
+    }
+}
+
+#[derive(Debug, Default, Deserialize)]
+pub struct PartialNodeConfig {
+    pub aliases: Option<Vec<NodeName>>,
+    pub tags: Option<Vec<String>>,
+}
+
+impl From<NodeConfig> for PartialNodeConfig {
+    fn from(node_config: NodeConfig) -> Self {
+        Self {
+            aliases: Some(node_config.aliases),
+            tags: Some(node_config.tags),
+        }
+    }
+}
+
 /// A filter rule.
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub enum NodeFilter {
@@ -240,30 +288,47 @@ impl NodeFilter {
         }
     }
 
-    /// Returns whether the filter has any rule matching NodeConfig information.
+    /// Returns which NodeConfig information is needed to evaluate the filter.
     ///
     /// Evaluating `config.deployment` can potentially be very expensive,
     /// especially when its values (e.g., tags) depend on other parts of
     /// the configuration.
-    pub fn has_node_config_rules(&self) -> bool {
+    pub fn needs_eval(&self) -> NeedsEval {
+        // XXX: is the hashset overkill?
         match self {
-            Self::MatchName(_) => false,
-            Self::MatchTag(_) => true,
-            Self::Union(v) => v.iter().any(|e| e.has_node_config_rules()),
-            Self::Inter(v) => v.iter().any(|e| e.has_node_config_rules()),
-            Self::Not(e) => e.has_node_config_rules(),
-            Self::Empty => false,
+            Self::MatchName(_) => NeedsEval {
+                aliases: true,
+                ..Default::default()
+            },
+            Self::MatchTag(_) => NeedsEval {
+                tags: true,
+                ..Default::default()
+            },
+            Self::Union(v) | Self::Inter(v) => v
+                .iter()
+                .fold(NeedsEval::default(), |acc, e| acc | e.needs_eval()),
+            Self::Not(e) => e.needs_eval(),
+            Self::Empty => NeedsEval::default(),
         }
     }
 
     /// Decides whether a node is accepted by the filter or not.
-    /// panic if the filter depends on tags and config is None
-    fn is_accepted(&self, name: &NodeName, config: Option<&NodeConfig>) -> bool {
+    /// panic if the filter depends on tags or aliases and they're None
+    fn is_accepted(&self, name: &NodeName, config: &PartialNodeConfig) -> bool {
         match self {
-            Self::MatchName(pat) => pat.matches(name.as_str()),
+            Self::MatchName(pat) => {
+                pat.matches(name.as_str())
+                    || config
+                        .aliases
+                        .as_ref()
+                        .expect("aliases missing")
+                        .iter()
+                        .any(|alias| pat.matches(&alias.0))
+            }
             Self::MatchTag(pat) => config
-                .unwrap()
-                .tags()
+                .tags
+                .as_ref()
+                .expect("tags missing")
                 .iter()
                 .any(|tag| pat.matches(tag.as_str())),
             Self::Union(v) => v.iter().any(|e| e.is_accepted(name, config)),
@@ -274,17 +339,17 @@ impl NodeFilter {
     }
 
     /// Runs the filter against a set of NodeConfigs and returns the matched ones.
-    pub fn filter_node_configs<'a, I>(&self, nodes: I) -> HashSet<NodeName>
+    pub fn filter_nodes<'a, I>(&self, nodes: I) -> HashSet<NodeName>
     where
-        I: Iterator<Item = (&'a NodeName, &'a NodeConfig)>,
+        I: Iterator<Item = (&'a NodeName, &'a PartialNodeConfig)>,
     {
         if self == &Self::Empty {
             return HashSet::new();
         }
 
         nodes
-            .filter_map(|(name, node)| {
-                if self.is_accepted(name, Some(node)) {
+            .filter_map(|(name, config)| {
+                if self.is_accepted(name, config) {
                     Some(name)
                 } else {
                     None
@@ -294,26 +359,34 @@ impl NodeFilter {
             .collect()
     }
 
-    /// Runs the filter against a set of node names and returns the matched ones.
-    pub fn filter_node_names(&self, nodes: &[NodeName]) -> ColmenaResult<HashSet<NodeName>> {
-        if self.has_node_config_rules() {
-            Err(ColmenaError::Unknown {
-                message: format!(
-                    "Not enough information to run rule {:?} - We only have node names",
-                    self
-                ),
-            })
-        } else {
-            Ok(nodes
-                .iter()
-                .filter_map(|name| {
-                    if self.is_accepted(name, None) {
-                        Some(name.clone())
-                    } else {
-                        None
+    /// In case of trivial filters which dont actually use any node info
+    /// Try to eval them immediately
+    pub fn try_eval_trivial(&self) -> Option<bool> {
+        match self {
+            Self::MatchName(_) => None,
+            Self::MatchTag(_) => None,
+            Self::Union(fs) => {
+                for f in fs {
+                    match f.try_eval_trivial() {
+                        None => return None,
+                        Some(true) => return Some(true),
+                        Some(false) => continue,
                     }
-                })
-                .collect())
+                }
+                Some(false)
+            }
+            Self::Inter(fs) => {
+                for f in fs {
+                    match f.try_eval_trivial() {
+                        None => return None,
+                        Some(true) => continue,
+                        Some(false) => return Some(false),
+                    }
+                }
+                Some(true)
+            }
+            Self::Not(f) => f.try_eval_trivial().map(|b| !b),
+            Self::Empty => Some(true),
         }
     }
 }
@@ -322,6 +395,36 @@ impl NodeFilter {
 mod tests {
     use super::*;
 
+    impl PartialNodeConfig {
+        fn known_empty() -> Self {
+            Self {
+                aliases: Some(vec![]),
+                tags: Some(vec![]),
+            }
+        }
+
+        pub fn known_aliases_tags(
+            aliases: Option<Vec<NodeName>>,
+            tags: Option<Vec<String>>,
+        ) -> Self {
+            Self { aliases, tags }
+        }
+
+        fn known_tags(tags: Vec<String>) -> Self {
+            Self {
+                aliases: Some(vec![]),
+                tags: Some(tags),
+            }
+        }
+
+        fn known_aliases(aliases: Vec<NodeName>) -> Self {
+            Self {
+                aliases: Some(aliases),
+                tags: Some(vec![]),
+            }
+        }
+    }
+
     use std::collections::{HashMap, HashSet};
 
     macro_rules! node {
@@ -424,126 +527,109 @@ mod tests {
     }
 
     #[test]
-    fn test_filter_node_names() {
-        let nodes = vec![node!("lax-alpha"), node!("lax-beta"), node!("sfo-gamma")];
+    fn test_filter_nodes_names_only() {
+        let nodes = vec![
+            (node!("lax-alpha"), PartialNodeConfig::known_empty()),
+            (node!("lax-beta"), PartialNodeConfig::known_empty()),
+            (node!("sfo-gamma"), PartialNodeConfig::known_empty()),
+        ];
 
         assert_eq!(
             &HashSet::from_iter([node!("lax-alpha")]),
             &NodeFilter::new("lax-alpha")
                 .unwrap()
-                .filter_node_names(&nodes)
-                .unwrap(),
+                .filter_nodes(nodes.iter().map(|x| (&x.0, &x.1))),
         );
 
         assert_eq!(
             &HashSet::from_iter([node!("lax-alpha"), node!("lax-beta")]),
             &NodeFilter::new("lax-*")
                 .unwrap()
-                .filter_node_names(&nodes)
-                .unwrap(),
+                .filter_nodes(nodes.iter().map(|x| (&x.0, &x.1))),
         );
     }
 
     #[test]
-    fn test_filter_node_configs() {
-        // TODO: Better way to mock
-        let template = NodeConfig {
-            tags: vec![],
-            target_host: None,
-            target_user: None,
-            target_port: None,
-            allow_local_deployment: false,
-            build_on_target: false,
-            replace_unknown_profiles: false,
-            privilege_escalation_command: vec![],
-            extra_ssh_options: vec![],
-            keys: HashMap::new(),
-            system_type: None,
-        };
-
-        let mut nodes = HashMap::new();
-
-        nodes.insert(
-            node!("alpha"),
-            NodeConfig {
-                tags: vec!["web".to_string(), "infra-lax".to_string()],
-                ..template.clone()
-            },
-        );
-
-        nodes.insert(
-            node!("beta"),
-            NodeConfig {
-                tags: vec!["router".to_string(), "infra-sfo".to_string()],
-                ..template.clone()
-            },
-        );
-
-        nodes.insert(
-            node!("gamma-a"),
-            NodeConfig {
-                tags: vec!["controller".to_string()],
-                ..template.clone()
-            },
-        );
-
-        nodes.insert(
-            node!("gamma-b"),
-            NodeConfig {
-                tags: vec!["ewaste".to_string()],
-                ..template
-            },
-        );
-
-        assert_eq!(4, nodes.len());
+    fn test_filter_nodes() {
+        let nodes: HashMap<NodeName, PartialNodeConfig> = HashMap::from([
+            (
+                node!("alpha"),
+                PartialNodeConfig::known_tags(vec!["web".to_string(), "infra-lax".to_string()]),
+            ),
+            (
+                node!("beta"),
+                PartialNodeConfig::known_tags(vec!["router".to_string(), "infra-sfo".to_string()]),
+            ),
+            (
+                node!("gamma-a"),
+                PartialNodeConfig::known_tags(vec!["controller".to_string()]),
+            ),
+            (
+                node!("gamma-b"),
+                PartialNodeConfig::known_tags(vec!["ewaste".to_string()]),
+            ),
+            (
+                node!("aliases-test"),
+                PartialNodeConfig::known_aliases_tags(
+                    Some(vec![node!("whatever-alias1"), node!("whatever-alias2")]),
+                    Some(vec!["testing".into()]),
+                ),
+            ),
+        ]);
+        assert_eq!(5, nodes.len());
 
         assert_eq!(
             &HashSet::from_iter([node!("alpha")]),
-            &NodeFilter::new("@web")
-                .unwrap()
-                .filter_node_configs(nodes.iter()),
+            &NodeFilter::new("@web").unwrap().filter_nodes(nodes.iter()),
         );
 
         assert_eq!(
             &HashSet::from_iter([node!("alpha"), node!("beta")]),
             &NodeFilter::new("@infra-*")
                 .unwrap()
-                .filter_node_configs(nodes.iter()),
+                .filter_nodes(nodes.iter()),
         );
 
         assert_eq!(
             &HashSet::from_iter([node!("beta"), node!("gamma-a")]),
             &NodeFilter::new("@router,@controller")
                 .unwrap()
-                .filter_node_configs(nodes.iter()),
+                .filter_nodes(nodes.iter()),
         );
 
         assert_eq!(
             &HashSet::from_iter([node!("beta"), node!("gamma-a"), node!("gamma-b")]),
             &NodeFilter::new("@router,gamma-*")
                 .unwrap()
-                .filter_node_configs(nodes.iter()),
+                .filter_nodes(nodes.iter()),
         );
 
         assert_eq!(
             &HashSet::from_iter([]),
             &NodeFilter::new("@router&@controller")
                 .unwrap()
-                .filter_node_configs(nodes.iter()),
+                .filter_nodes(nodes.iter()),
         );
 
         assert_eq!(
             &HashSet::from_iter([node!("beta")]),
             &NodeFilter::new("@router&@infra-*")
                 .unwrap()
-                .filter_node_configs(nodes.iter()),
+                .filter_nodes(nodes.iter()),
         );
 
         assert_eq!(
             &HashSet::from_iter([node!("alpha")]),
             &NodeFilter::new("!@router&@infra-*")
                 .unwrap()
-                .filter_node_configs(nodes.iter()),
+                .filter_nodes(nodes.iter()),
+        );
+
+        assert_eq!(
+            &HashSet::from_iter([node!("aliases-test")]),
+            &NodeFilter::new("whatever-alias1")
+                .unwrap()
+                .filter_nodes(nodes.iter()),
         );
     }
 }