Initial commit

.gitignore

@@ -0,0 +1 @@
+/target

Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "tmpl"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+argparse = "0.2.2"
+file-mode = { version = "0.1.2", features = ["serde"] }
+serde = { version = "1.0.195", features = ["derive"] }
+serde_yaml = "0.9.30"
+tera = "1.19.1"
+thiserror = "1.0.56"
+tracing = { version = "0.1.40", features = ["log"] }
+tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }

src/main.rs

@@ -0,0 +1,120 @@
+mod model;
+
+use std::path::PathBuf;
+use std::io::Read;
+
+use argparse::{ArgumentParser, Store, StoreOption};
+use serde::de::DeserializeOwned;
+use serde_yaml::Value;
+use tera::{Context, Tera};
+use tracing::error;
+
+use model::Instructions;
+
+#[derive(Debug, thiserror::Error)]
+enum LoadError {
+    #[error("{0}")]
+    Io(#[from] std::io::Error),
+    #[error("{0}")]
+    Yaml(#[from] serde_yaml::Error),
+}
+
+#[derive(Debug, thiserror::Error)]
+enum ProcessInstructionsError {
+    #[error("Error loading templates: {0}")]
+    Tera(#[from] tera::Error),
+}
+
+#[derive(Default)]
+struct Args {
+    instructions: String,
+    values: String,
+    templates: Option<String>,
+    destdir: Option<PathBuf>,
+}
+
+fn parse_args(args: &mut Args) {
+    let mut parser = ArgumentParser::new();
+    parser
+        .refer(&mut args.instructions)
+        .required()
+        .add_argument("instructions", Store, "Instructions");
+    parser
+        .refer(&mut args.values)
+        .required()
+        .add_argument("values", Store, "Values");
+    parser.refer(&mut args.templates).add_option(
+        &["--templates", "-t"],
+        StoreOption,
+        "Templates directory",
+    );
+    parser.refer(&mut args.destdir).add_option(
+        &["--destdir", "-d"],
+        StoreOption,
+        "Destination directory",
+    );
+    parser.parse_args_or_exit();
+}
+
+fn main() {
+    tracing_subscriber::fmt()
+        .with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
+        .with_writer(std::io::stderr)
+        .init();
+
+    let mut args: Args = Default::default();
+    parse_args(&mut args);
+    let instructions = match load_yaml(&args.instructions) {
+        Ok(i) => i,
+        Err(e) => {
+            error!(
+                "Could not load instructions from {}: {}",
+                args.instructions, e
+            );
+            std::process::exit(1);
+        }
+    };
+    let values = match load_yaml(&args.values) {
+        Ok(i) => i,
+        Err(e) => {
+            error!("Could not load values from {}: {}", args.values, e);
+            std::process::exit(1);
+        }
+    };
+    let templates = args.templates.as_deref().unwrap_or("templates");
+    if let Err(e) = process_instructions(templates, instructions, values) {
+        error!("Failed to process instructions: {}", e);
+        std::process::exit(1);
+    }
+}
+
+fn load_yaml<T: DeserializeOwned>(path: &str) -> Result<T, LoadError> {
+    let mut yaml = vec![];
+    if path == "-" {
+        std::io::stdin().read_to_end(&mut yaml)?;
+    } else {
+        let mut f = std::fs::File::open(path)?;
+        f.read_to_end(&mut yaml)?;
+    }
+    Ok(serde_yaml::from_slice(&yaml)?)
+}
+
+fn process_instructions(
+    templates: &str,
+    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) {
+            Ok(o) => {
+                print!("{}", o);
+            }
+            Err(e) => {
+                error!("Failed to render template {}: {}", i.template, e);
+            }
+        }
+    }
+    Ok(())
+}

src/model.rs

@@ -0,0 +1,17 @@
+use std::path::PathBuf;
+
+use serde::Deserialize;
+
+#[derive(Debug, Deserialize)]
+pub struct RenderInstruction {
+    pub template: String,
+    pub dest: PathBuf,
+    pub owner: Option<String>,
+    pub group: Option<String>,
+    pub mode: Option<String>,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct Instructions {
+    pub render: Vec<RenderInstruction>,
+}