4 files changed, 76 insertions, 0 deletions
diff --git a/src/garage/cli/convert_db.rs b/src/garage/cli/convert_db.rs
new file mode 100644
index 00000000..f590a4b6
--- /dev/null
+++ b/src/garage/cli/convert_db.rs
@@ -0,0 +1,65 @@
+use std::path::PathBuf;
+
+use structopt::StructOpt;
+
+use garage_db::*;
+
+/// K2V command line interface
+#[derive(StructOpt, Debug)]
+pub struct ConvertDbOpt {
+	/// Input database path (not the same as metadata_dir, see
+	/// https://garagehq.deuxfleurs.fr/documentation/reference-manual/configuration/#db-engine-since-v0-8-0)
+	#[structopt(short = "i")]
+	input_path: PathBuf,
+	/// Input database engine (sled, lmdb or sqlite; limited by db engines
+	/// enabled in this build)
+	#[structopt(short = "a")]
+	input_engine: String,
+
+	/// Output database path
+	#[structopt(short = "o")]
+	output_path: PathBuf,
+	/// Output database engine
+	#[structopt(short = "b")]
+	output_engine: String,
+}
+
+pub(crate) fn do_conversion(args: ConvertDbOpt) -> Result<()> {
+	let input = open_db(args.input_path, args.input_engine)?;
+	let output = open_db(args.output_path, args.output_engine)?;
+	output.import(&input)?;
+	Ok(())
+}
+
+fn open_db(path: PathBuf, engine: String) -> Result<Db> {
+	match engine.as_str() {
+		#[cfg(feature = "sled")]
+		"sled" => {
+			let db = sled_adapter::sled::Config::default().path(&path).open()?;
+			Ok(sled_adapter::SledDb::init(db))
+		}
+		#[cfg(feature = "sqlite")]
+		"sqlite" | "sqlite3" | "rusqlite" => {
+			let db = sqlite_adapter::rusqlite::Connection::open(&path)?;
+			Ok(sqlite_adapter::SqliteDb::init(db))
+		}
+		#[cfg(feature = "lmdb")]
+		"lmdb" | "heed" => {
+			std::fs::create_dir_all(&path).map_err(|e| {
+				Error(format!("Unable to create LMDB data directory: {}", e).into())
+			})?;
+
+			let map_size = lmdb_adapter::recommended_map_size();
+
+			let db = lmdb_adapter::heed::EnvOpenOptions::new()
+				.max_dbs(100)
+				.map_size(map_size)
+				.open(&path)
+				.unwrap();
+			Ok(lmdb_adapter::LmdbDb::init(db))
+		}
+		e => Err(Error(
+			format!("Invalid or unsupported DB engine: {}", e).into(),
+		)),
+	}
+}
diff --git a/src/garage/cli/mod.rs b/src/garage/cli/mod.rs
index 17a2d8ce..e131f62c 100644
--- a/src/garage/cli/mod.rs
+++ b/src/garage/cli/mod.rs
@@ -4,6 +4,8 @@ pub(crate) mod layout;
 pub(crate) mod structs;
 pub(crate) mod util;
 
+pub(crate) mod convert_db;
+
 pub(crate) use cmd::*;
 pub(crate) use init::*;
 pub(crate) use layout::*;
diff --git a/src/garage/cli/structs.rs b/src/garage/cli/structs.rs
index 6e585e53..ee7c2988 100644
--- a/src/garage/cli/structs.rs
+++ b/src/garage/cli/structs.rs
@@ -3,6 +3,8 @@ use structopt::StructOpt;
 
 use garage_util::version::garage_version;
 
+use crate::cli::convert_db;
+
 #[derive(StructOpt, Debug)]
 pub enum Command {
 	/// Run Garage server
@@ -54,6 +56,10 @@ pub enum Command {
 	/// Low-level debug operations on data blocks
 	#[structopt(name = "block", version = garage_version())]
 	Block(BlockOperation),
+
+	/// Convert metadata db between database engine formats
+	#[structopt(name = "convert-db", version = garage_version())]
+	ConvertDb(convert_db::ConvertDbOpt),
 }
 
 #[derive(StructOpt, Debug)]
diff --git a/src/garage/main.rs b/src/garage/main.rs
index ab84fa11..a9f1ad29 100644
--- a/src/garage/main.rs
+++ b/src/garage/main.rs
@@ -188,6 +188,9 @@ async fn main() {
 		Command::OfflineRepair(repair_opt) => {
 			repair::offline::offline_repair(opt.config_file, opt.secrets, repair_opt).await
 		}
+		Command::ConvertDb(conv_opt) => {
+			cli::convert_db::do_conversion(conv_opt).map_err(From::from)
+		}
 		Command::Node(NodeOperation::NodeId(node_id_opt)) => {
 			node_id_command(opt.config_file, node_id_opt.quiet)
 		}