Add new function: parse_hosts_json

Cargo.toml

@@ -13,5 +13,6 @@ mlua = { version = "0.10.1", features = ["anyhow", "async", "luajit", "macros",
 rand = "0.8.5"
 regex = "1.11.1"
 rustyline = "15.0.0"
+serde_json = "1.0.133"
 ssh2 = { version = "0.9.4", features = ["vendored-openssl"] }
 tokio = { version = "1.42.0", features = ["io-std", "macros", "rt"] }

README.md

@@ -139,6 +139,7 @@ For detailed explanations, arguments, and examples of each module, please refer
 Komandan offers built-in functions to enhance scripting capabilities:
 
 -   **`komandan.filter_hosts`**: Filters a list of hosts based on a pattern.
+-   **`komandan.parse_hosts_json`**: Parses a JSON file containing hosts information.
 -   **`komandan.set_defaults`**: Sets default values for host connection parameters.
 
 For detailed descriptions and usage examples of these functions, please visit the [Built-in Functions section of the Komandan Documentation Site](https://komandan.vercel.app/docs/functions/).

examples/parse_hosts_json.lua

@@ -0,0 +1,15 @@
+local hosts = komandan.parse_hosts_json("/path/to/hosts.json")
+
+komandan.set_defaults({
+    user = "user1",
+    private_key_file = os.getenv("HOME") .. "/.ssh/id_ed25519",
+})
+
+for _, host in pairs(hosts) do
+    komandan.komando(host, {
+        name = "Create a directory",
+        komandan.modules.cmd({
+            cmd = "mkdir /tmp/newdir1",
+        }),
+    })
+end

src/main.rs

@@ -13,7 +13,7 @@ mod ssh;
 mod util;
 mod validator;
 
-use util::{dprint, filter_hosts, regex_is_match};
+use util::{dprint, filter_hosts, parse_hosts_json, regex_is_match};
 use validator::{validate_host, validate_module, validate_task};
 
 #[tokio::main(flavor = "current_thread")]
@@ -70,6 +70,7 @@ fn setup_komandan_table(lua: &Lua) -> mlua::Result<()> {
     // Add utils
     komandan.set("regex_is_match", lua.create_function(regex_is_match)?)?;
     komandan.set("filter_hosts", lua.create_function(filter_hosts)?)?;
+    komandan.set("parse_hosts_json", lua.create_function(parse_hosts_json)?)?;
     komandan.set("dprint", lua.create_function(dprint)?)?;
 
     // Add core modules
@@ -443,6 +444,7 @@ mod tests {
         assert!(komandan_table.contains_key("komando").unwrap());
         assert!(komandan_table.contains_key("regex_is_match").unwrap());
         assert!(komandan_table.contains_key("filter_hosts").unwrap());
+        assert!(komandan_table.contains_key("parse_hosts_json").unwrap());
         assert!(komandan_table.contains_key("dprint").unwrap());
 
         let modules_table = komandan_table.get::<Table>("modules").unwrap();

src/util.rs

@@ -1,6 +1,7 @@
-use crate::args::Args;
+use crate::{args::Args, validator::validate_host};
 use clap::Parser;
-use mlua::{chunk, Lua, Table, Value};
+use mlua::{chunk, Error::RuntimeError, Lua, LuaSerdeExt, Table, Value};
+use std::{fs::File, io::Read};
 
 pub fn dprint(lua: &Lua, value: Value) -> mlua::Result<()> {
     let args = Args::parse();
@@ -91,6 +92,58 @@ pub fn filter_hosts(lua: &Lua, (hosts, pattern): (Value, Value)) -> mlua::Result
     Ok(matched_hosts)
 }
 
+pub fn parse_hosts_json(lua: &Lua, src: Value) -> mlua::Result<Table> {
+    let src = match src.as_string_lossy() {
+        Some(s) => s,
+        None => return Err(RuntimeError(String::from("Invalid src path"))),
+    };
+
+    let mut file = match File::open(&src) {
+        Ok(f) => f,
+        Err(_) => return Err(RuntimeError(String::from("Failed to open JSON file"))),
+    };
+
+    let mut content = String::new();
+    match file.read_to_string(&mut content) {
+        Ok(_) => (),
+        Err(_) => return Err(RuntimeError(String::from("Failed to read JSON file"))),
+    };
+
+    let json: serde_json::Value = match serde_json::from_str(&content) {
+        Ok(j) => j,
+        Err(_) => return Err(RuntimeError(String::from("Failed to parse JSON file"))),
+    };
+
+    let hosts = lua.create_table()?;
+
+    let lua_value = match lua.to_value(&json) {
+        Ok(o) => o,
+        Err(_) => return Err(RuntimeError(String::from("Failed to convert JSON to Lua"))),
+    };
+
+    let lua_table = match lua_value.as_table() {
+        Some(t) => t,
+        None => return Err(RuntimeError(String::from("JSON does not contain a table"))),
+    };
+
+    for pair in lua_table.pairs() {
+        let (_, value): (Value, Value) = pair?;
+        match validate_host(&lua, value) {
+            Ok(host) => {
+                hosts.set(hosts.len()? + 1, host)?;
+            }
+            Err(_) => {}
+        };
+    }
+
+    dprint(
+        lua,
+        lua.to_value(&format!("Loaded {} hosts from '{}'", hosts.len()?, src))?,
+    )?;
+
+    Ok(hosts)
+}
+
 pub fn regex_is_match(
     _: &Lua,
     (text, pattern): (mlua::String, mlua::String),