Cleanup of EtcTree.

src/activate/etc_files.rs

@@ -13,7 +13,7 @@ use std::{fs, io};
 
 use crate::{
     create_link, create_store_link, remove_dir, remove_file, remove_link, StorePath,
-    ETC_STATE_FILE_NAME, SYSTEM_MANAGER_STATE_DIR,
+    ETC_STATE_FILE_NAME, SYSTEM_MANAGER_STATE_DIR, SYSTEM_MANAGER_STATIC_NAME,
 };
 use etc_tree::EtcTree;
 
@@ -57,16 +57,16 @@ pub fn activate(store_path: &StorePath, ephemeral: bool) -> Result<()> {
     DirBuilder::new().recursive(true).create(&etc_dir)?;
 
     let old_state = read_created_files()?;
+    let initial_state = EtcTree::root_node();
 
-    // TODO: constant?
-    let static_dir_name = ".system-manager-static";
     let (state, status) = create_etc_static_link(
-        static_dir_name,
+        SYSTEM_MANAGER_STATIC_NAME,
         &config.static_env,
         &etc_dir,
-        EtcTree::new(PathBuf::new()),
+        initial_state,
     );
     status?;
+
     let new_state = create_etc_links(config.entries.values(), &etc_dir, state).update_state(
         old_state,
         &|path| {
@@ -75,7 +75,7 @@ pub fn activate(store_path: &StorePath, ephemeral: bool) -> Result<()> {
         },
     );
 
-    serialise_state(&new_state.unwrap_or_else(|| EtcTree::new(PathBuf::from("/"))))?;
+    serialise_state(new_state)?;
 
     log::info!("Done");
     Ok(())
@@ -85,17 +85,15 @@ pub fn deactivate() -> Result<()> {
     let state = read_created_files()?;
     log::debug!("{:?}", state);
 
-    serialise_state(&state.deactivate_managed_entry(
+    serialise_state(state.deactivate(&|path| {
-        Path::new("/"),
+        try_delete_path(path)
-        &|path| match try_delete_path(path) {
+            .map_err(|e| {
-            Ok(()) => true,
-            Err(e) => {
                 log::error!("Error deleting path: {}", path.display());
                 log::error!("{e}");
-                false
+                e
-            }
+            })
-        },
+            .is_ok()
-    ))?;
+    }))?;
 
     log::info!("Done");
     Ok(())
@@ -154,7 +152,7 @@ fn create_etc_link(link_target: &OsStr, etc_dir: &Path, state: EtcTree) -> (EtcT
     match status.and_then(|_| {
         create_link(
             Path::new(".")
-                .join(".system-manager-static")
+                .join(SYSTEM_MANAGER_STATIC_NAME)
                 .join("etc")
                 .join(link_target)
                 .as_path(),
@@ -207,7 +205,7 @@ fn create_dir_recursively(dir: &Path, state: EtcTree) -> (EtcTree, Result<()>) {
     let (new_state, _, status) = dir
         .components()
         .fold_while(
-            (state, PathBuf::from("/"), Ok(())),
+            (state, PathBuf::from(path::MAIN_SEPARATOR_STR), Ok(())),
             |(state, path, _), component| match component {
                 Component::RootDir => Continue((state, path, Ok(()))),
                 Component::Normal(dir) => {
@@ -240,10 +238,15 @@ fn create_dir_recursively(dir: &Path, state: EtcTree) -> (EtcTree, Result<()>) {
 }
 
 fn copy_file(source: &Path, target: &Path, mode: &str) -> Result<()> {
+    let exists = target.try_exists()?;
+    if !exists {
         fs::copy(source, target)?;
-    let mode_int = u32::from_str_radix(mode, 8).map_err(anyhow::Error::from)?;
+        let mode_int = u32::from_str_radix(mode, 8)?;
         fs::set_permissions(target, Permissions::from_mode(mode_int))?;
         Ok(())
+    } else {
+        anyhow::bail!("File {} already exists, ignoring.", target.display());
+    }
 }
 
 fn etc_dir(ephemeral: bool) -> PathBuf {
@@ -254,7 +257,10 @@ fn etc_dir(ephemeral: bool) -> PathBuf {
     }
 }
 
-fn serialise_state(created_files: &EtcTree) -> Result<()> {
+fn serialise_state<E>(created_files: Option<E>) -> Result<()>
+where
+    E: AsRef<EtcTree>,
+{
     let state_file = Path::new(SYSTEM_MANAGER_STATE_DIR).join(ETC_STATE_FILE_NAME);
     DirBuilder::new()
         .recursive(true)
@@ -262,7 +268,12 @@ fn serialise_state(created_files: &EtcTree) -> Result<()> {
 
     log::info!("Writing state info into file: {}", state_file.display());
     let writer = io::BufWriter::new(fs::File::create(state_file)?);
-    serde_json::to_writer(writer, created_files)?;
+
+    if let Some(e) = created_files {
+        serde_json::to_writer(writer, e.as_ref())?;
+    } else {
+        serde_json::to_writer(writer, &EtcTree::default())?;
+    }
     Ok(())
 }
 
@@ -283,5 +294,5 @@ fn read_created_files() -> Result<EtcTree> {
             }
         }
     }
-    Ok(EtcTree::new(PathBuf::from("/")))
+    Ok(EtcTree::default())
 }

src/activate/etc_files/etc_tree.rs

@@ -1,22 +1,10 @@
 use im::HashMap;
 use serde::{Deserialize, Serialize};
 use std::cmp::Eq;
-use std::ffi::OsString;
 use std::iter::Peekable;
 use std::path;
 use std::path::{Path, PathBuf};
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
-#[serde(rename_all = "camelCase")]
-pub struct EtcTree {
-    status: EtcFileStatus,
-    path: PathBuf,
-    // TODO directories and files are now both represented as a string associated with a nested
-    // map. For files the nested map is simple empty.
-    // We could potentially optimise this.
-    nested: HashMap<OsString, EtcTree>,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub enum EtcFileStatus {
@@ -35,22 +23,45 @@ impl EtcFileStatus {
     }
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct EtcTree {
+    status: EtcFileStatus,
+    path: PathBuf,
+    // TODO directories and files are now both represented as a string associated with a nested
+    // map. For files the nested map is simple empty.
+    // We could potentially optimise this.
+    nested: HashMap<String, EtcTree>,
+}
+
+impl AsRef<EtcTree> for EtcTree {
+    fn as_ref(&self) -> &EtcTree {
+        self
+    }
+}
+
+impl Default for EtcTree {
+    fn default() -> Self {
+        Self::root_node()
+    }
+}
+
 /// Data structure to represent files that are managed by system-manager.
 ///
 /// This data will be serialised to disk and read on the next run.
 ///
 /// We need these basic operations:
-/// 1. Create a new, empty structure
+/// 1. Create a new root structure
 /// 2. Persist to a file
 /// 3. Import from a file
 /// 4. Add a path to the tree, that will from then on be considered as managed
 /// 5.
 impl EtcTree {
-    pub fn new(path: PathBuf) -> Self {
+    fn new(path: PathBuf) -> Self {
         Self::with_status(path, EtcFileStatus::Unmanaged)
     }
 
-    pub fn with_status(path: PathBuf, status: EtcFileStatus) -> Self {
+    fn with_status(path: PathBuf, status: EtcFileStatus) -> Self {
         Self {
             status,
             path,
@@ -58,6 +69,10 @@ impl EtcTree {
         }
     }
 
+    pub fn root_node() -> Self {
+        Self::new(PathBuf::from(path::MAIN_SEPARATOR_STR))
+    }
+
     // TODO is recursion OK here?
     // Should we convert to CPS and use a crate like tramp to TCO this?
     pub fn register_managed_entry(self, path: &Path) -> Self {
@@ -75,26 +90,24 @@ impl EtcTree {
                                     maybe_subtree.unwrap_or_else(|| {
                                         EtcTree::with_status(
                                             new_path.to_owned(),
-                                            if components.peek().is_some() {
+                                            components
+                                                .peek()
+                                                .map_or(EtcFileStatus::Managed, |_| {
                                                     EtcFileStatus::Unmanaged
-                                            } else {
+                                                }),
-                                                EtcFileStatus::Managed
-                                            },
                                         )
                                     }),
                                     components,
                                     new_path,
                                 ))
                             },
-                            name.to_owned(),
+                            name.to_string_lossy().to_string(),
                         );
                         tree
                     }
-                    path::Component::RootDir => go(
+                    path::Component::RootDir => {
-                        tree,
+                        go(tree, components, path.join(path::MAIN_SEPARATOR_STR))
-                        components,
+                    }
-                        path.join(path::MAIN_SEPARATOR.to_string()),
-                    ),
                     _ => panic!(
                         "Unsupported path provided! At path component: {:?}",
                         component
@@ -131,63 +144,6 @@ impl EtcTree {
         }
     }
 
-    pub fn deactivate_managed_entry<F>(self, path: &Path, delete_action: &F) -> Self
-    where
-        F: Fn(&Path) -> bool,
-    {
-        fn go<'a, C, F>(
-            mut tree: EtcTree,
-            path: PathBuf,
-            mut components: Peekable<C>,
-            delete_action: &F,
-        ) -> EtcTree
-        where
-            C: Iterator<Item = path::Component<'a>>,
-            F: Fn(&Path) -> bool,
-        {
-            log::debug!("Deactivating {}", path.display());
-
-            if let Some(component) = components.next() {
-                match component {
-                    path::Component::Normal(name) => {
-                        let new_path = path.join(name);
-                        tree.nested = tree.nested.alter(
-                            |maybe_subtree| {
-                                maybe_subtree.and_then(|subtree| {
-                                    if components.peek().is_some() {
-                                        Some(go(subtree, new_path, components, delete_action))
-                                    } else {
-                                        subtree.deactivate(delete_action)
-                                    }
-                                })
-                            },
-                            name.to_owned(),
-                        );
-                        tree
-                    }
-                    path::Component::RootDir => go(
-                        tree,
-                        path.join(path::MAIN_SEPARATOR.to_string()),
-                        components,
-                        delete_action,
-                    ),
-                    _ => panic!(
-                        "Unsupported path provided! At path component: {:?}",
-                        component
-                    ),
-                }
-            } else {
-                tree
-            }
-        }
-        go(
-            self,
-            PathBuf::new(),
-            path.components().peekable(),
-            delete_action,
-        )
-    }
-
     pub fn update_state<F>(self, other: Self, delete_action: &F) -> Option<Self>
     where
         F: Fn(&Path) -> bool,
@@ -237,29 +193,86 @@ impl EtcTree {
 mod tests {
     use super::*;
     use itertools::Itertools;
-    use std::ffi::OsStr;
+
+    impl EtcTree {
+        pub fn deactivate_managed_entry<F>(self, path: &Path, delete_action: &F) -> Self
+        where
+            F: Fn(&Path) -> bool,
+        {
+            fn go<'a, C, F>(
+                mut tree: EtcTree,
+                path: PathBuf,
+                mut components: Peekable<C>,
+                delete_action: &F,
+            ) -> EtcTree
+            where
+                C: Iterator<Item = path::Component<'a>>,
+                F: Fn(&Path) -> bool,
+            {
+                log::debug!("Deactivating {}", path.display());
+
+                if let Some(component) = components.next() {
+                    match component {
+                        path::Component::Normal(name) => {
+                            let new_path = path.join(name);
+                            tree.nested = tree.nested.alter(
+                                |maybe_subtree| {
+                                    maybe_subtree.and_then(|subtree| {
+                                        if components.peek().is_some() {
+                                            Some(go(subtree, new_path, components, delete_action))
+                                        } else {
+                                            subtree.deactivate(delete_action)
+                                        }
+                                    })
+                                },
+                                name.to_string_lossy().to_string(),
+                            );
+                            tree
+                        }
+                        path::Component::RootDir => go(
+                            tree,
+                            path.join(path::MAIN_SEPARATOR.to_string()),
+                            components,
+                            delete_action,
+                        ),
+                        _ => panic!(
+                            "Unsupported path provided! At path component: {:?}",
+                            component
+                        ),
+                    }
+                } else {
+                    tree
+                }
+            }
+            go(
+                self,
+                PathBuf::new(),
+                path.components().peekable(),
+                delete_action,
+            )
+        }
+    }
 
     #[test]
     fn etc_tree_register() {
-        let tree1 = EtcTree::new(PathBuf::from("/"))
+        let tree = EtcTree::root_node()
             .register_managed_entry(&PathBuf::from("/").join("foo").join("bar"))
             .register_managed_entry(&PathBuf::from("/").join("foo2").join("baz").join("bar"))
             .register_managed_entry(&PathBuf::from("/").join("foo2").join("baz2").join("bar"));
-        dbg!(&tree1);
+        dbg!(&tree);
         assert_eq!(
-            tree1.nested.keys().sorted().collect::<Vec<_>>(),
+            tree.nested.keys().sorted().collect::<Vec<_>>(),
             ["foo", "foo2"]
         );
         assert_eq!(
-            tree1
+            tree.nested
-                .nested
+                .get("foo2")
-                .get(OsStr::new("foo2"))
                 .unwrap()
                 .nested
-                .get(OsStr::new("baz"))
+                .get("baz")
                 .unwrap()
                 .nested
-                .get(OsStr::new("bar"))
+                .get("bar")
                 .unwrap()
                 .path,
             PathBuf::from("/").join("foo2").join("baz").join("bar")
@@ -268,7 +281,7 @@ mod tests {
 
     #[test]
     fn etc_tree_deactivate() {
-        let tree1 = EtcTree::new(PathBuf::from("/"))
+        let tree1 = EtcTree::root_node()
             .register_managed_entry(&PathBuf::from("/").join("foo").join("bar"))
             .register_managed_entry(&PathBuf::from("/").join("foo2"))
             .register_managed_entry(&PathBuf::from("/").join("foo2").join("baz"))
@@ -301,10 +314,10 @@ mod tests {
         );
         assert!(tree2
             .nested
-            .get(OsStr::new("foo3"))
+            .get("foo3")
             .unwrap()
             .nested
-            .get(OsStr::new("baz2"))
+            .get("baz2")
             .unwrap()
             .nested
             .keys()
@@ -319,7 +332,7 @@ mod tests {
 
     #[test]
     fn etc_tree_update_state() {
-        let tree1 = EtcTree::new(PathBuf::from("/"))
+        let tree1 = EtcTree::root_node()
             .register_managed_entry(&PathBuf::from("/").join("foo").join("bar"))
             .register_managed_entry(&PathBuf::from("/").join("foo2"))
             .register_managed_entry(&PathBuf::from("/").join("foo2").join("baz"))
@@ -327,7 +340,7 @@ mod tests {
             .register_managed_entry(&PathBuf::from("/").join("foo2").join("baz2"))
             .register_managed_entry(&PathBuf::from("/").join("foo2").join("baz2").join("bar"))
             .register_managed_entry(&PathBuf::from("/").join("foo3").join("baz2").join("bar"));
-        let tree2 = EtcTree::new(PathBuf::from("/"))
+        let tree2 = EtcTree::root_node()
             .register_managed_entry(&PathBuf::from("/").join("foo").join("bar"))
             .register_managed_entry(&PathBuf::from("/").join("foo3").join("bar"))
             .register_managed_entry(&PathBuf::from("/").join("foo4"))

src/lib.rs

@@ -15,6 +15,7 @@ const GCROOT_PATH: &str = "/nix/var/nix/gcroots/system-manager-current";
 const SYSTEM_MANAGER_STATE_DIR: &str = "/var/lib/system-manager/state";
 const SERVICES_STATE_FILE_NAME: &str = "services.json";
 const ETC_STATE_FILE_NAME: &str = "etc-files.json";
+const SYSTEM_MANAGER_STATIC_NAME: &str = ".system-manager-static";
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(from = "String", into = "String", rename_all = "camelCase")]