feat: create Volumes impl for overlay file system

7 files changed, 289 insertions, 11 deletions

diff --git a/Cargo.lock b/Cargo.lock
index b931472..94c8fc3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -450,6 +450,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "fs_extra"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2022715d62ab30faffd124d40b76f4134a550a87792276512b18d63272333394"
+
+[[package]]
 name = "futures"
 version = "0.3.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1311,6 +1317,15 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "73b4b750c782965c211b42f022f59af1fbceabdd026623714f104152f1ec149f"
 
 [[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
+[[package]]
 name = "schannel"
 version = "0.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1351,18 +1366,18 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.136"
+version = "1.0.137"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789"
+checksum = "61ea8d54c77f8315140a05f4c7237403bf38b72704d031543aa1d16abbf517d1"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.136"
+version = "1.0.137"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08597e7152fcd306f41838ed3e37be9eaeed2b61c42e2117266a554fab4662f9"
+checksum = "1f26faba0c3959972377d3b2d306ee9f71faee9714294e41bb777f83f88578be"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1505,9 +1520,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.86"
+version = "1.0.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a65b3f4ffa0092e9887669db0eae07941f023991ab58ea44da8fe8e2d511c6b"
+checksum = "04066589568b72ec65f42d65a1a52436e954b168773148893c020269563decf2"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1572,18 +1587,18 @@ checksum = "b1141d4d61095b28419e22cb0bbf02755f5e54e0526f97f1e3d1d160e60885fb"
 
 [[package]]
 name = "thiserror"
-version = "1.0.30"
+version = "1.0.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "854babe52e4df1653706b98fcfc05843010039b406875930a70e4d9644e5c417"
+checksum = "bd829fe32373d27f76265620b5309d0340cb8550f523c1dda251d6298069069a"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.30"
+version = "1.0.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa32fd3f627f367fe16f893e2597ae3c05020f8bba2666a4e6ea73d377e5714b"
+checksum = "0396bc89e626244658bef819e22d0cc459e795a5ebe878e6ec336d1674a8d79a"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1985,6 +2000,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 
 [[package]]
+name = "walkdir"
+version = "2.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "808cf2735cd4b6866113f648b791c6adc5714537bc222d9347bb203386ffda56"
+dependencies = [
+ "same-file",
+ "winapi",
+ "winapi-util",
+]
+
+[[package]]
 name = "want"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2248,6 +2274,18 @@ dependencies = [
 ]
 
 [[package]]
+name = "zone_overlay"
+version = "0.1.0"
+dependencies = [
+ "figment",
+ "fs_extra",
+ "serde",
+ "thiserror",
+ "walkdir",
+ "zone_core",
+]
+
+[[package]]
 name = "zone_zfs"
 version = "0.1.0"
 dependencies = [
diff --git a/Cargo.toml b/Cargo.toml
index 20679e1..191b691 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,3 +1,3 @@
 [workspace]
-members = ["zone", "zone_core", "zone_nspawn", "zone_zfs", "zoned"]
+members = ["zone", "zone_core", "zone_nspawn", "zone_zfs", "zone_overlay", "zoned"]
 default-members = ["zone", "zoned"]
diff --git a/zone_overlay/Cargo.toml b/zone_overlay/Cargo.toml
new file mode 100644
index 0000000..97f3590
--- /dev/null
+++ b/zone_overlay/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "zone_overlay"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+figment = { version = "0.10.6", features = ["toml", "env"] }
+fs_extra = "1.2.0"
+serde = { version = "1.0.137", features = ["derive"] }
+thiserror = "1.0.31"
+walkdir = "2.3.2"
+zone_core = { version = "0.1.0", path = "../zone_core" }
diff --git a/zone_overlay/src/config.rs b/zone_overlay/src/config.rs
new file mode 100644
index 0000000..b7a7821
--- /dev/null
+++ b/zone_overlay/src/config.rs
@@ -0,0 +1,94 @@
+use figment::{
+    error::Result,
+    providers::Serialized,
+    value::{Dict, Map},
+    Figment, Metadata, Profile, Provider,
+};
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+pub struct Config {
+    pub volumes: PathBuf,
+    pub templates: PathBuf,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Config {
+            volumes: "/tmp/zone/volumes".into(),
+            templates: "/tmp/zone/templates".into(),
+        }
+    }
+}
+
+impl Config {
+    pub fn from<T: Provider>(provider: T) -> Result<Config> {
+        Figment::from(provider).extract()
+    }
+}
+
+impl Provider for Config {
+    fn metadata(&self) -> Metadata {
+        Metadata::named("zone_overlay Config")
+    }
+
+    fn data(&self) -> Result<Map<Profile, Dict>> {
+        Serialized::defaults(Config::default()).data()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use figment::providers::{Format, Serialized, Toml};
+
+    use super::*;
+
+    #[test]
+    fn defaults() {
+        figment::Jail::expect_with(|jail| {
+            jail.create_file(
+                "Config.toml",
+                r#"
+                volumes = "/tmp/zone/volumes"
+                templates = "/tmp/zone/templates"
+                "#,
+            )?;
+
+            let config: Config = Figment::from(Serialized::defaults(Config::default()))
+                .merge(Toml::file("Config.toml"))
+                .extract()?;
+
+            assert_eq!(config, Config::default());
+
+            Ok(())
+        });
+    }
+
+    #[test]
+    fn non_defaults() {
+        figment::Jail::expect_with(|jail| {
+            jail.create_file(
+                "Config.toml",
+                r#"
+                volumes = "/svr/zone/volumes"
+                templates = "/svr/zone/templates"
+                "#,
+            )?;
+
+            let config: Config = Figment::from(Serialized::defaults(Config::default()))
+                .merge(Toml::file("Config.toml"))
+                .extract()?;
+
+            assert_eq!(
+                config,
+                Config {
+                    volumes: "/svr/zone/volumes".into(),
+                    templates: "/svr/zone/templates".into(),
+                }
+            );
+
+            Ok(())
+        });
+    }
+}
diff --git a/zone_overlay/src/error.rs b/zone_overlay/src/error.rs
new file mode 100644
index 0000000..65663ad
--- /dev/null
+++ b/zone_overlay/src/error.rs
@@ -0,0 +1,29 @@
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error("Volume error: {0:?}")]
+    Volume(#[from] VolumeError),
+
+    #[error("Template error: {0:?}")]
+    Template(#[from] TemplateError),
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum VolumeError {
+    #[error("Volume does not exist")]
+    NotFound,
+
+    #[error("Volume directory does not exist")]
+    BasePath,
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum TemplateError {
+    #[error("Template does not exist")]
+    NotFound,
+
+    #[error("Template directory does not exist: {0:?}")]
+    BasePath(std::io::Error),
+
+    #[error("Copy error: {0:?}")]
+    Copy(#[from] fs_extra::error::Error),
+}
diff --git a/zone_overlay/src/lib.rs b/zone_overlay/src/lib.rs
new file mode 100644
index 0000000..a0cdfcf
--- /dev/null
+++ b/zone_overlay/src/lib.rs
@@ -0,0 +1,16 @@
+pub use config::Config;
+pub use error::Error;
+pub use overlay::Overlay;
+
+mod config;
+mod error;
+mod overlay;
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        let result = 2 + 2;
+        assert_eq!(result, 4);
+    }
+}
diff --git a/zone_overlay/src/overlay.rs b/zone_overlay/src/overlay.rs
new file mode 100644
index 0000000..5f2cf58
--- /dev/null
+++ b/zone_overlay/src/overlay.rs
@@ -0,0 +1,87 @@
+use fs_extra::dir;
+use std::path::PathBuf;
+use walkdir::WalkDir;
+use zone_core::{Container, Templates, Volumes};
+
+use crate::{
+    error::{TemplateError, VolumeError},
+    Config, Error,
+};
+
+#[derive(Default, Debug)]
+pub struct Overlay {
+    pub config: Config,
+}
+
+impl Volumes for Overlay {
+    type Error = Error;
+
+    fn list_volumes(&self) -> Result<Vec<Container>, Self::Error> {
+        if !&self.config.volumes.is_dir() {
+            return Err(VolumeError::BasePath.into());
+        }
+
+        let containers = WalkDir::new(&self.config.volumes)
+            .max_depth(2)
+            .into_iter()
+            .filter_entry(|entry| entry.file_type().is_dir() && entry.depth() == 2)
+            .filter_map(|res| res.map(|entry| entry.into_path()).ok())
+            .filter_map(
+                |path_buf| match path_buf.strip_prefix(&self.config.volumes) {
+                    Ok(p) => Container::try_from(PathBuf::from(p)).ok(),
+                    Err(_) => None,
+                },
+            )
+            .collect();
+
+        Ok(containers)
+    }
+
+    fn get_volume(&self, container: &Container) -> Result<PathBuf, Self::Error> {
+        match self
+            .config
+            .volumes
+            .join(PathBuf::from(container.to_owned()))
+        {
+            path if path.is_dir() => Ok(path),
+            _ => Err(VolumeError::NotFound.into()),
+        }
+    }
+}
+
+impl Templates for Overlay {
+    type Error = Error;
+
+    fn list_templates(&self) -> Result<Vec<String>, Self::Error> {
+        let templates = std::fs::read_dir(&self.config.templates)
+            .map_err(TemplateError::BasePath)?
+            .into_iter()
+            .filter_map(|e| match e {
+                Ok(e) if e.path().is_dir() => e.file_name().to_str().map(String::from),
+                _ => None,
+            })
+            .collect();
+
+        Ok(templates)
+    }
+
+    fn clone_from(&self, template: String, owner: String) -> Result<Container, Self::Error> {
+        let container = Container {
+            id: self.get_last_id(&template, &owner)?,
+            template,
+            owner,
+        };
+
+        let to = &self
+            .config
+            .volumes
+            .join(PathBuf::from(container.to_owned()));
+
+        let from = &self.config.templates.join(&container.template);
+
+        dir::copy(from, to, &Default::default())
+            .map(|_| container)
+            .map_err(TemplateError::from)
+            .map_err(Error::from)
+    }
+}