Introduce alternative to EnvCommand

The `EnvCommand` was designed when there was no built in way to stream stdout & stderr to the user and also when I was not as experienced with Rust.

The `commons::cmd` takes a few things that were nice about EnvCommand and modularizes them so they can be used piece-meal.

Core goals:

- Talk to the user, includes display functions to render commands to the user
- Consistent errors, Errors need to include maximum information including command and stdout/stderr. Good display by default.
- Consistent experience mapping user versus OS errors.

Author: schneems

Cargo.lock

@@ -1,8 +1,6 @@
 use crate::{BundleWithout, RubyBuildpack, RubyBuildpackError};
 use commons::{
-    display::SentenceList,
-    env_command::{CommandError, EnvCommand},
-    gemfile_lock::ResolvedRubyVersion,
+    cmd, cmd::CmdError, display::SentenceList, gemfile_lock::ResolvedRubyVersion,
     metadata_digest::MetadataDigest,
 };
 use libcnb::{
@@ -12,6 +10,7 @@ use libcnb::{
     layer_env::{LayerEnv, ModificationBehavior, Scope},
     Env,
 };
+use libherokubuildpack::command::CommandExt;
 use libherokubuildpack::log as user;
 use serde::{Deserialize, Serialize};
 use std::path::Path;
@@ -337,11 +336,12 @@ fn layer_env(layer_path: &Path, app_dir: &Path, without_default: &BundleWithout)
 /// # Errors
 ///
 /// When the 'bundle install' command fails this function returns an error.
-fn bundle_install(env: &Env) -> Result<(), CommandError> {
+///
+fn bundle_install(env: &Env) -> Result<(), CmdError> {
     // ## Run `$ bundle install`
-    let command = EnvCommand::new_show_keys(
-        "bundle",
-        &["install"],
+    let mut command = cmd::create("bundle", &["install"], env);
+    let command_string = cmd::display_with_keys(
+        &command,
         env,
         [
             "BUNDLE_BIN",
@@ -353,9 +353,13 @@ fn bundle_install(env: &Env) -> Result<(), CommandError> {
         ],
     );
 
-    user::log_info(format!("\nRunning command:\n$ {command}"));
+    user::log_info(format!("\nRunning command:\n$ {command_string}"));
 
-    command.stream()?;
+    command
+        .output_and_write_streams(std::io::stdout(), std::io::stderr())
+        .map_err(cmd::os_command_error)
+        .and_then(|output| cmd::check_non_zero(output, cmd::OutputState::AlreadyStreamed))
+        .map_err(|error| CmdError::new(command_string, error))?;
 
     Ok(())
 }

buildpacks/ruby/src/layers/bundle_install_layer.rs

@@ -3,6 +3,7 @@
 #![allow(clippy::module_name_repetitions)]
 use crate::layers::{RubyInstallError, RubyInstallLayer};
 use commons::cache::CacheError;
+use commons::cmd::CmdError;
 use commons::env_command::CommandError;
 use commons::gem_list::GemList;
 use commons::gemfile_lock::GemfileLock;
@@ -169,7 +170,7 @@ pub(crate) enum RubyBuildpackError {
     MissingGemfileLock(std::io::Error),
     InAppDirCacheError(CacheError),
     BundleInstallDigestError(commons::metadata_digest::DigestError),
-    BundleInstallCommandError(CommandError),
+    BundleInstallCommandError(CmdError),
     RakeAssetsPrecompileFailed(CommandError),
     GemInstallBundlerCommandError(CommandError),
 }

buildpacks/ruby/src/main.rs

@@ -18,6 +18,7 @@ sha2 = "0.10"
 tempfile = "3"
 thiserror = "1"
 walkdir = "2"
+lazy_static = "1.4.0"
 
 [dev-dependencies]
 filetime = "0.2"