Add efforts to automate eth1 testnet deployment

eth2/utils/eth2_testnet/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "eth2_testnet"
+version = "0.1.0"
+authors = ["Paul Hauner <paul@paulhauner.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dev-dependencies]
+tempdir = "0.3"
+
+[dependencies]
+serde = "1.0"
+serde_json = "^1.0"

eth2/utils/eth2_testnet/src/lib.rs

@@ -0,0 +1,134 @@
+//! This crate should eventually represent the structure at this repo:
+//!
+//! https://github.com/eth2-clients/eth2-testnets/tree/master/nimbus/testnet1
+//!
+//! It is not accurate at the moment, we include extra files and we also don't support a few
+//! others. We are unable to confirm to the repo until we have the following PR merged:
+//!
+//! https://github.com/sigp/lighthouse/pull/605
+
+use std::fs::{create_dir_all, File};
+use std::path::PathBuf;
+
+pub const ADDRESS_FILE: &str = "deposit_contract.txt";
+pub const DEPLOY_BLOCK_FILE: &str = "deploy_block.txt";
+pub const MIN_GENESIS_TIME_FILE: &str = "min_genesis_time.txt";
+
+#[derive(Clone, PartialEq, Debug)]
+pub struct Eth2TestnetDir {
+    pub deposit_contract_address: String,
+    pub deposit_contract_deploy_block: u64,
+    pub min_genesis_time: u64,
+}
+
+impl Eth2TestnetDir {
+    pub fn new(
+        base_dir: PathBuf,
+        deposit_contract_address: String,
+        deposit_contract_deploy_block: u64,
+        min_genesis_time: u64,
+    ) -> Result<Self, String> {
+        if base_dir.exists() {
+            return Err("Testnet directory already exists".to_string());
+        }
+
+        create_dir_all(&base_dir)
+            .map_err(|e| format!("Unable to create testnet directory: {:?}", e))?;
+
+        File::create(base_dir.join(ADDRESS_FILE))
+            .map_err(|e| format!("Unable to create {}: {:?}", ADDRESS_FILE, e))
+            .and_then(|file| {
+                serde_json::to_writer(file, &deposit_contract_address)
+                    .map_err(|e| format!("Unable to write {}: {:?}", ADDRESS_FILE, e))
+            })?;
+
+        File::create(base_dir.join(DEPLOY_BLOCK_FILE))
+            .map_err(|e| format!("Unable to create {}: {:?}", DEPLOY_BLOCK_FILE, e))
+            .and_then(|file| {
+                serde_json::to_writer(file, &deposit_contract_deploy_block)
+                    .map_err(|e| format!("Unable to write {}: {:?}", DEPLOY_BLOCK_FILE, e))
+            })?;
+
+        File::create(base_dir.join(MIN_GENESIS_TIME_FILE))
+            .map_err(|e| format!("Unable to create {}: {:?}", MIN_GENESIS_TIME_FILE, e))
+            .and_then(|file| {
+                serde_json::to_writer(file, &min_genesis_time)
+                    .map_err(|e| format!("Unable to write {}: {:?}", MIN_GENESIS_TIME_FILE, e))
+            })?;
+
+        Ok(Self {
+            deposit_contract_address,
+            deposit_contract_deploy_block,
+            min_genesis_time,
+        })
+    }
+
+    pub fn load(base_dir: PathBuf) -> Result<Self, String> {
+        let deposit_contract_address = File::open(base_dir.join(ADDRESS_FILE))
+            .map_err(|e| format!("Unable to open {}: {:?}", ADDRESS_FILE, e))
+            .and_then(|file| {
+                serde_json::from_reader(file)
+                    .map_err(|e| format!("Unable to parse {}: {:?}", ADDRESS_FILE, e))
+            })?;
+
+        let deposit_contract_deploy_block = File::open(base_dir.join(DEPLOY_BLOCK_FILE))
+            .map_err(|e| format!("Unable to open {}: {:?}", DEPLOY_BLOCK_FILE, e))
+            .and_then(|file| {
+                serde_json::from_reader(file)
+                    .map_err(|e| format!("Unable to parse {}: {:?}", DEPLOY_BLOCK_FILE, e))
+            })?;
+
+        let min_genesis_time = File::open(base_dir.join(MIN_GENESIS_TIME_FILE))
+            .map_err(|e| format!("Unable to open {}: {:?}", MIN_GENESIS_TIME_FILE, e))
+            .and_then(|file| {
+                serde_json::from_reader(file)
+                    .map_err(|e| format!("Unable to parse {}: {:?}", MIN_GENESIS_TIME_FILE, e))
+            })?;
+
+        Ok(Self {
+            deposit_contract_address,
+            deposit_contract_deploy_block,
+            min_genesis_time,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempdir::TempDir;
+
+    #[test]
+    fn round_trip() {
+        let temp_dir = TempDir::new("eth2_testnet_test").expect("should create temp dir");
+        let base_dir = PathBuf::from(temp_dir.path().join("my_testnet"));
+        let deposit_contract_address = "0xBB9bc244D798123fDe783fCc1C72d3Bb8C189413".to_string();
+        let deposit_contract_deploy_block = 42;
+        let min_genesis_time = 1337;
+
+        let testnet = Eth2TestnetDir::new(
+            base_dir.clone(),
+            deposit_contract_address.clone(),
+            deposit_contract_deploy_block,
+            min_genesis_time,
+        )
+        .expect("should create struct");
+
+        let decoded = Eth2TestnetDir::load(base_dir).expect("should load struct");
+
+        assert_eq!(
+            decoded.deposit_contract_address, deposit_contract_address,
+            "deposit_contract_address"
+        );
+        assert_eq!(
+            decoded.deposit_contract_deploy_block, deposit_contract_deploy_block,
+            "deposit_contract_deploy_block"
+        );
+        assert_eq!(
+            decoded.min_genesis_time, min_genesis_time,
+            "min_genesis_time"
+        );
+
+        assert_eq!(testnet, decoded, "should decode as encoded");
+    }
+}