Add a feature to create automatically a random temporary directory for base path & remove Clone (#6221)

* Initial commit

Forked at: 4adac40c07
Parent branch: origin/master

* Add a feature to create automatically a temporary directory for base path

* doc fix and todos

* use parking_lot instead

* use refcell instead since we stay in the main thread

* remove Clone derives

* add test

* solving dependency issue

* clarifying doc

* conflict argument with base-path

* WIP

Forked at: 4adac40c07
Parent branch: origin/master

* revert dep deletion

* fixing test and making base_path optional

* hold basepath while the service is running

* fixes

* Update client/cli/src/params/shared_params.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Update client/service/Cargo.toml

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Update client/cli/src/commands/mod.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Update client/service/src/config.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* WIP

Forked at: 4adac40c07
Parent branch: origin/master

* improve doc

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/client/service/src/config.rs

@@ -24,12 +24,14 @@ pub use sc_network::config::{ExtTransport, MultiaddrWithPeerId, NetworkConfigura
 pub use sc_executor::WasmExecutionMethod;
 use sc_client_api::execution_extensions::ExecutionStrategies;
 
-use std::{future::Future, path::{PathBuf, Path}, pin::Pin, net::SocketAddr, sync::Arc};
+use std::{io, future::Future, path::{PathBuf, Path}, pin::Pin, net::SocketAddr, sync::Arc};
 pub use sc_transaction_pool::txpool::Options as TransactionPoolOptions;
 use sc_chain_spec::ChainSpec;
 use sp_core::crypto::Protected;
 pub use sc_telemetry::TelemetryEndpoints;
 use prometheus_endpoint::Registry;
+#[cfg(not(target_os = "unknown"))]
+use tempfile::TempDir;
 
 /// Service configuration.
 pub struct Configuration {
@@ -102,6 +104,8 @@ pub struct Configuration {
 	pub max_runtime_instances: usize,
 	/// Announce block automatically after they have been imported
 	pub announce_block: bool,
+	/// Base path of the configuration
+	pub base_path: Option<BasePath>,
 }
 
 /// Type for tasks spawned by the executor.
@@ -191,3 +195,59 @@ impl Default for RpcMethods {
 		RpcMethods::Auto
 	}
 }
+
+/// The base path that is used for everything that needs to be write on disk to run a node.
+pub enum BasePath {
+	/// A temporary directory is used as base path and will be deleted when dropped.
+	#[cfg(not(target_os = "unknown"))]
+	Temporary(TempDir),
+	/// A path on the disk.
+	Permanenent(PathBuf),
+}
+
+impl BasePath {
+	/// Create a `BasePath` instance using a temporary directory prefixed with "substrate" and use
+	/// it as base path.
+	///
+	/// Note: the temporary directory will be created automatically and deleted when the `BasePath`
+	/// instance is dropped.
+	#[cfg(not(target_os = "unknown"))]
+	pub fn new_temp_dir() -> io::Result<BasePath> {
+		Ok(BasePath::Temporary(
+			tempfile::Builder::new().prefix("substrate").tempdir()?,
+		))
+	}
+
+	/// Create a `BasePath` instance based on an existing path on disk.
+	///
+	/// Note: this function will not ensure that the directory exist nor create the directory. It
+	/// will also not delete the directory when the instance is dropped.
+	pub fn new<P: AsRef<Path>>(path: P) -> BasePath {
+		BasePath::Permanenent(path.as_ref().to_path_buf())
+	}
+
+	/// Create a base path from values describing the project.
+	#[cfg(not(target_os = "unknown"))]
+	pub fn from_project(qualifier: &str, organization: &str, application: &str) -> BasePath {
+		BasePath::new(
+			directories::ProjectDirs::from(qualifier, organization, application)
+				.expect("app directories exist on all supported platforms; qed")
+				.data_local_dir(),
+		)
+	}
+
+	/// Retrieve the base path.
+	pub fn path(&self) -> &Path {
+		match self {
+			#[cfg(not(target_os = "unknown"))]
+			BasePath::Temporary(temp_dir) => temp_dir.path(),
+			BasePath::Permanenent(path) => path.as_path(),
+		}
+	}
+}
+
+impl std::convert::From<PathBuf> for BasePath {
+	fn from(path: PathBuf) -> Self {
+		BasePath::new(path)
+	}
+}