Add DumpConfigs

validator_manager/src/lib.rs

@@ -1,12 +1,36 @@
 use clap::App;
 use clap::ArgMatches;
 use environment::Environment;
+use serde::Serialize;
+use std::path::PathBuf;
 use types::EthSpec;
+use validators::create_validators::write_to_json_file;
 
 mod validators;
 
 pub const CMD: &str = "validator_manager";
 
+/// This flag is on the top-level `lighthouse` binary.
+const DUMP_CONFIGS_FLAG: &str = "dump-configs";
+
+/// Used only in testing, this allows a command to dump its configuration to a file and then exit
+/// successfully. This allows for testing how the CLI arguments translate to some configuration.
+pub enum DumpConfigs {
+    Disabled,
+    Enabled(PathBuf),
+}
+
+impl DumpConfigs {
+    /// Returns `Ok(true)` if the configuration was successfully written to a file and the
+    /// application should exit successfully without doing anything else.
+    pub fn should_exit_early<T: Serialize>(&self, config: &T) -> Result<bool, String> {
+        match self {
+            DumpConfigs::Disabled => Ok(false),
+            DumpConfigs::Enabled(dump_path) => write_to_json_file(dump_path, config).map(|()| true),
+        }
+    }
+}
+
 pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
     App::new(CMD)
         .visible_aliases(&["vm", CMD])
@@ -21,6 +45,9 @@ pub fn run<'a, T: EthSpec>(
 ) -> Result<(), String> {
     let context = env.core_context();
     let spec = context.eth2_config.spec.clone();
+    let dump_configs = clap_utils::parse_optional(matches, DUMP_CONFIGS_FLAG)?
+        .map(DumpConfigs::Enabled)
+        .unwrap_or_else(|| DumpConfigs::Disabled);
 
     context
         .executor
@@ -31,7 +58,7 @@ pub fn run<'a, T: EthSpec>(
             async {
                 match matches.subcommand() {
                     (validators::CMD, Some(matches)) => {
-                        validators::cli_run::<T>(matches, &spec).await
+                        validators::cli_run::<T>(matches, &spec, dump_configs).await
                     }
                     (unknown, _) => Err(format!(
                         "{} is not a valid {} command. See --help.",

validator_manager/src/validators/create_validators.rs

@@ -1,4 +1,5 @@
 use super::common::*;
+use crate::DumpConfigs;
 use account_utils::{random_password_string, read_mnemonic_from_cli, read_password_from_user};
 use clap::{App, Arg, ArgMatches};
 use eth2::{
@@ -7,7 +8,7 @@ use eth2::{
     BeaconNodeHttpClient, SensitiveUrl, Timeouts,
 };
 use eth2_wallet::WalletBuilder;
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use std::fs;
 use std::path::{Path, PathBuf};
 use std::time::Duration;
@@ -180,7 +181,7 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
 
 /// The CLI arguments are parsed into this struct before running the application. This step of
 /// indirection allows for testing the underlying logic without needing to parse CLI arguments.
-#[derive(Clone)]
+#[derive(Clone, Serialize, Deserialize)]
 pub struct CreateConfig {
     pub output_path: PathBuf,
     pub first_index: u32,
@@ -460,9 +461,14 @@ impl ValidatorsAndDeposits {
 pub async fn cli_run<'a, T: EthSpec>(
     matches: &'a ArgMatches<'a>,
     spec: &ChainSpec,
+    dump_configs: DumpConfigs,
 ) -> Result<(), String> {
     let config = CreateConfig::from_cli(matches, spec)?;
-    run::<T>(config, spec).await
+    if dump_configs.should_exit_early(&config)? {
+        Ok(())
+    } else {
+        run::<T>(config, spec).await
+    }
 }
 
 async fn run<'a, T: EthSpec>(config: CreateConfig, spec: &ChainSpec) -> Result<(), String> {
@@ -506,7 +512,10 @@ async fn run<'a, T: EthSpec>(config: CreateConfig, spec: &ChainSpec) -> Result<(
 /// Write some object to a file as JSON.
 ///
 /// The file must be created new, it must not already exist.
-fn write_to_json_file<P: AsRef<Path>, S: Serialize>(path: P, contents: &S) -> Result<(), String> {
+pub fn write_to_json_file<P: AsRef<Path>, S: Serialize>(
+    path: P,
+    contents: &S,
+) -> Result<(), String> {
     eprintln!("Writing {:?}", path.as_ref());
     let mut file = fs::OpenOptions::new()
         .write(true)

validator_manager/src/validators/import_validators.rs

@@ -1,4 +1,5 @@
 use super::common::*;
+use crate::DumpConfigs;
 use clap::{App, Arg, ArgMatches};
 use eth2::{
     lighthouse_vc::{
@@ -7,6 +8,7 @@ use eth2::{
     },
     SensitiveUrl,
 };
+use serde::{Deserialize, Serialize};
 use std::fs;
 use std::path::PathBuf;
 
@@ -72,7 +74,7 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
         )
 }
 
-#[derive(Clone)]
+#[derive(Clone, Serialize, Deserialize)]
 struct ImportConfig {
     validators_file_path: PathBuf,
     vc_url: SensitiveUrl,
@@ -91,9 +93,16 @@ impl ImportConfig {
     }
 }
 
-pub async fn cli_run<'a>(matches: &'a ArgMatches<'a>) -> Result<(), String> {
+pub async fn cli_run<'a>(
+    matches: &'a ArgMatches<'a>,
+    dump_configs: DumpConfigs,
+) -> Result<(), String> {
     let config = ImportConfig::from_cli(matches)?;
-    run(config).await
+    if dump_configs.should_exit_early(&config)? {
+        Ok(())
+    } else {
+        run(config).await
+    }
 }
 
 async fn run<'a>(config: ImportConfig) -> Result<(), String> {

validator_manager/src/validators/mod.rs

@@ -2,6 +2,7 @@ pub mod common;
 pub mod create_validators;
 pub mod import_validators;
 
+use crate::DumpConfigs;
 use clap::{App, ArgMatches};
 use types::{ChainSpec, EthSpec};
 
@@ -17,12 +18,15 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
 pub async fn cli_run<'a, T: EthSpec>(
     matches: &'a ArgMatches<'a>,
     spec: &ChainSpec,
+    dump_configs: DumpConfigs,
 ) -> Result<(), String> {
     match matches.subcommand() {
         (create_validators::CMD, Some(matches)) => {
-            create_validators::cli_run::<T>(matches, spec).await
+            create_validators::cli_run::<T>(matches, spec, dump_configs).await
+        }
+        (import_validators::CMD, Some(matches)) => {
+            import_validators::cli_run(matches, dump_configs).await
         }
-        (import_validators::CMD, Some(matches)) => import_validators::cli_run(matches).await,
         (unknown, _) => Err(format!(
             "{} does not have a {} command. See --help",
             CMD, unknown