Render templates to file and set permissions

Cargo.lock

@@ -168,6 +168,33 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "derive-adhoc"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5283ac2881753c76c0892406705553f0d9ab30649f81e18964d3408f4501edb8"
+dependencies = [
+ "derive-adhoc-macros",
+ "heck",
+]
+
+[[package]]
+name = "derive-adhoc-macros"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c21b673a9b8c78c34908e6fcb42b922e11c4df2de5237f1c3f58d3285904a84b"
+dependencies = [
+ "heck",
+ "itertools",
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "sha3",
+ "strum",
+ "syn 1.0.109",
+ "void",
+]
+
 [[package]]
 name = "deunicode"
 version = "1.4.2"
@@ -184,6 +211,12 @@ dependencies = [
  "crypto-common",
 ]
 
+[[package]]
+name = "either"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a26ae43d7bcc3b814de94796a5e736d4029efb0ee900c12e2d54c993ad1a1e07"
+
 [[package]]
 name = "equivalent"
 version = "1.0.1"
@@ -251,6 +284,12 @@ version = "0.14.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "290f1a1d9242c78d09ce40a5e87e7554ee637af1351968159f4952f028f75604"
 
+[[package]]
+name = "heck"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
+
 [[package]]
 name = "humansize"
 version = "2.1.3"
@@ -309,6 +348,15 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1c173a5686ce8bfa551b3563d0c2170bf24ca44da99c7ca4bfdab5418c3fe57"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.10"
@@ -324,6 +372,15 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "keccak"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f6d5ed8676d904364de097082f4e7d240b571b67989ced0240f08b7f966f940"
+dependencies = [
+ "cpufeatures",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -403,6 +460,12 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "paste"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de3145af08024dea9fa9914f381a17b8fc6034dfb00f3a84013f7ff43f29ed4c"
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.1"
@@ -440,7 +503,7 @@ dependencies = [
  "pest_meta",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.48",
 ]
 
 [[package]]
@@ -504,6 +567,16 @@ version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b40af805b3121feab8a3c29f04d8ad262fa8e0561883e7653e024ae4479e6de"
 
+[[package]]
+name = "proc-macro-crate"
+version = "1.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f4c021e1093a56626774e81216a4ce732a735e5bad4868a03f3ed65ca0c3919"
+dependencies = [
+ "once_cell",
+ "toml_edit",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.76"
@@ -513,6 +586,18 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "pwd-grp"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6955c41fd7e4283bdf6ff3e7218b7e3f8ef24c4236b31d22be050f4cfd5e2a2c"
+dependencies = [
+ "derive-adhoc",
+ "libc",
+ "paste",
+ "thiserror",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.35"
@@ -596,6 +681,12 @@ version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c08c74e62047bb2de4ff487b251e4a92e24f48745648451635cec7d591162d9f"
 
+[[package]]
+name = "rustversion"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ffc183a10b4478d04cbbbfc96d0873219d962dd5accaff2ffbd4ceb7df837f4"
+
 [[package]]
 name = "ryu"
 version = "1.0.16"
@@ -628,7 +719,7 @@ checksum = "46fe8f8603d81ba86327b23a2e9cdf49e1255fb94a4c5f297f6ee0547178ea2c"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.48",
 ]
 
 [[package]]
@@ -666,6 +757,16 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "sha3"
+version = "0.10.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75872d278a8f37ef87fa0ddbda7802605cb18344497949862c0d4dcb291eba60"
+dependencies = [
+ "digest",
+ "keccak",
+]
+
 [[package]]
 name = "sharded-slab"
 version = "0.1.7"
@@ -697,6 +798,39 @@ version = "1.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4dccd0940a2dcdf68d092b8cbab7dc0ad8fa938bf95787e1b916b0e3d0e8e970"
 
+[[package]]
+name = "strum"
+version = "0.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "290d54ea6f91c969195bdbcd7442c8c2a2ba87da8bf60a7ee86a235d4bc1e125"
+dependencies = [
+ "strum_macros",
+]
+
+[[package]]
+name = "strum_macros"
+version = "0.25.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23dc1fa9ac9c169a78ba62f0b841814b7abae11bdd047b9c58f893439e309ea0"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "rustversion",
+ "syn 2.0.48",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.109"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.48"
@@ -747,7 +881,7 @@ checksum = "fa0faa943b50f3db30a20aa7e265dbc66076993efed8463e8de414e5d06d3471"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.48",
 ]
 
 [[package]]
@@ -766,6 +900,7 @@ version = "0.1.0"
 dependencies = [
  "argparse",
  "file-mode",
+ "pwd-grp",
  "serde",
  "serde_yaml",
  "tera",
@@ -774,6 +909,23 @@ dependencies = [
  "tracing-subscriber",
 ]
 
+[[package]]
+name = "toml_datetime"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3550f4e9685620ac18a50ed434eb3aec30db8ba93b0287467bca5826ea25baf1"
+
+[[package]]
+name = "toml_edit"
+version = "0.19.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b5bb770da30e5cbfde35a2d7b9b8a2c4b8ef89548a7a6aeab5c9a576e3e7421"
+dependencies = [
+ "indexmap",
+ "toml_datetime",
+ "winnow",
+]
+
 [[package]]
 name = "tracing"
 version = "0.1.40"
@@ -794,7 +946,7 @@ checksum = "34704c8d6ebcbc939824180af020566b01a7c01f80641264eba0999f6c2b6be7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.48",
 ]
 
 [[package]]
@@ -922,6 +1074,12 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
+[[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
+
 [[package]]
 name = "walkdir"
 version = "2.4.0"
@@ -959,7 +1117,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.48",
  "wasm-bindgen-shared",
 ]
 
@@ -981,7 +1139,7 @@ checksum = "f0eb82fcb7930ae6219a7ecfd55b217f5f0893484b7a13022ebb2b2bf20b5283"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.48",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -1145,3 +1303,12 @@ name = "windows_x86_64_msvc"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
+
+[[package]]
+name = "winnow"
+version = "0.5.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b7cf47b659b318dccbd69cc4797a39ae128f533dce7902a1096044d1967b9c16"
+dependencies = [
+ "memchr",
+]

Cargo.toml

@@ -8,6 +8,7 @@ edition = "2021"
 [dependencies]
 argparse = "0.2.2"
 file-mode = { version = "0.1.2", features = ["serde"] }
+pwd-grp = "0.1.1"
 serde = { version = "1.0.195", features = ["derive"] }
 serde_yaml = "0.9.30"
 tera = "1.19.1"

src/main.rs

@@ -1,13 +1,13 @@
 mod model;
 
-use std::path::PathBuf;
+use std::io::{Read, Seek, Write};
-use std::io::Read;
+use std::path::{Path, PathBuf};
 
 use argparse::{ArgumentParser, Store, StoreOption};
 use serde::de::DeserializeOwned;
 use serde_yaml::Value;
 use tera::{Context, Tera};
-use tracing::error;
+use tracing::{debug, error, info};
 
 use model::Instructions;
 
@@ -19,6 +19,18 @@ enum LoadError {
     Yaml(#[from] serde_yaml::Error),
 }
 
+#[derive(Debug, thiserror::Error)]
+enum SetPermissionsError {
+    #[error("{0}")]
+    Io(#[from] std::io::Error),
+    #[error("User not found: {0}")]
+    UserNotFound(String),
+    #[error("Group not found: {0}")]
+    GroupNotFound(String),
+    #[error("Bad mode string")]
+    BadMode,
+}
+
 #[derive(Debug, thiserror::Error)]
 enum ProcessInstructionsError {
     #[error("Error loading templates: {0}")]
@@ -82,7 +94,10 @@ fn main() {
         }
     };
     let templates = args.templates.as_deref().unwrap_or("templates");
-    if let Err(e) = process_instructions(templates, instructions, values) {
+    let destdir = args.destdir.as_deref().unwrap_or(Path::new("/"));
+    if let Err(e) =
+        process_instructions(templates, destdir, instructions, values)
+    {
         error!("Failed to process instructions: {}", e);
         std::process::exit(1);
     }
@@ -101,20 +116,110 @@ fn load_yaml<T: DeserializeOwned>(path: &str) -> Result<T, LoadError> {
 
 fn process_instructions(
     templates: &str,
+    destdir: impl AsRef<Path>,
     instructions: Instructions,
     values: Value,
 ) -> Result<(), ProcessInstructionsError> {
     let tera = Tera::new(&format!("{}/**", templates))?;
     let ctx = Context::from_serialize(&values)?;
     for i in instructions.render {
-        match tera.render(&i.template, &ctx) {
+        let out = match tera.render(&i.template, &ctx) {
-            Ok(o) => {
+            Ok(o) => o,
-                print!("{}", o);
-            }
             Err(e) => {
                 error!("Failed to render template {}: {}", i.template, e);
+                continue;
+            }
+        };
+        let mut dest = PathBuf::from(destdir.as_ref());
+        dest.push(i.dest.strip_prefix("/").unwrap_or(i.dest.as_path()));
+        if let Err(e) = write_file(&dest, out.as_bytes()) {
+            error!("Failed to write output file {}: {}", dest.display(), e);
+            continue;
+        }
+        if i.owner.is_some() || i.group.is_some() {
+            if let Err(e) =
+                chown(&dest, i.owner.as_deref(), i.group.as_deref())
+            {
+                error!("Failed to set ownership of {}: {}", dest.display(), e);
+            }
+        }
+        if let Some(mode) = i.mode {
+            if let Err(e) = chmod(&dest, &mode) {
+                error!("Failed to set mode of {}: {}", dest.display(), e);
             }
         }
     }
     Ok(())
 }
+
+fn write_file(
+    dest: impl AsRef<Path>,
+    data: &[u8],
+) -> Result<(), std::io::Error> {
+    if let Some(p) = dest.as_ref().parent() {
+        if !p.exists() {
+            info!("Creating directory {}", p.display());
+            std::fs::create_dir_all(p)?;
+        }
+    }
+    debug!("Writing output: {}", dest.as_ref().display());
+    let mut f = std::fs::File::create(&dest)?;
+    f.write_all(data)?;
+    let size = f.stream_position()?;
+    info!("Wrote output: {} ({} bytes)", dest.as_ref().display(), size);
+    Ok(())
+}
+
+fn chown(
+    path: impl AsRef<Path>,
+    owner: Option<&str>,
+    group: Option<&str>,
+) -> Result<(), SetPermissionsError> {
+    let uid = if let Some(owner) = owner {
+        debug!("Looking up UID for user {}", owner);
+        if let Some(pw) = pwd_grp::getpwnam(owner)? {
+            debug!("Found UID {} for user {}", pw.uid, owner);
+            Some(pw.uid)
+        } else {
+            return Err(SetPermissionsError::UserNotFound(owner.into()));
+        }
+    } else {
+        None
+    };
+    let gid = if let Some(group) = group {
+        debug!("Looking up GID for group {}", group);
+        if let Some(gr) = pwd_grp::getgrnam(group)? {
+            debug!("Found GID {} for group {}", gr.gid, group);
+            Some(gr.gid)
+        } else {
+            return Err(SetPermissionsError::GroupNotFound(group.into()));
+        }
+    } else {
+        None
+    };
+    debug!(
+        "Setting ownership of {} to {:?} / {:?}",
+        path.as_ref().display(),
+        uid,
+        gid
+    );
+    Ok(std::os::unix::fs::chown(path, uid, gid)?)
+}
+
+fn chmod(
+    path: impl AsRef<Path>,
+    mode: &str,
+) -> Result<(), SetPermissionsError> {
+    let mut filemode = file_mode::Mode::empty();
+    filemode
+        .set_str(mode)
+        .map_err(|_| SetPermissionsError::BadMode)?;
+    debug!(
+        "Changing mode of {} to {:o}",
+        path.as_ref().display(),
+        filemode.mode()
+    );
+    let newmode = filemode.set_mode_path(&path)?;
+    info!("Set mode of {} to {:o}", path.as_ref().display(), newmode);
+    Ok(())
+}