Enable external metastores

.github/workflows/ci.yml

@@ -35,6 +35,8 @@ jobs:
         with:
           path: ~/.cache/pre-commit
           key: pre-commit-${{ runner.os }}-pre-commit-${{ hashFiles('**/.pre-commit-config.yaml') }}
+      - name: Install protoc
+        run: sudo apt install -y protobuf-compiler
 
       # Use https://github.com/marketplace/actions/rust-cache
 

Cargo.toml

@@ -1,4 +1,5 @@
 [workspace]
+members = ["clade"]
 
 [package]
 name = "seafowl"
@@ -44,6 +45,7 @@ base64 = "0.21.0"
 
 bytes = "1.4.0"
 chrono = { version = "0.4", default_features = false }
+clade = { path = "clade" }
 clap = { version = "3.2.19", features = [ "derive" ] }
 config = "0.13.3"
 
@@ -90,6 +92,7 @@ sqlx = { version = "0.7.1", features = [ "runtime-tokio-rustls", "sqlite", "any"
 strum = ">=0.24"
 strum_macros = ">=0.24"
 tempfile = "3"
+thiserror = "1"
 tokio = { version = "1.0", features = ["macros", "rt", "rt-multi-thread", "signal", "process"] }
 tonic = { version = "0.10.0", optional = true }
 url = "2.2"
@@ -106,6 +109,7 @@ assert_cmd = "2"
 assert_unordered = "0.3"
 rstest = "*"
 serial_test = "2"
+tonic-reflection = "0.10"
 wiremock = "0.5"
 
 [build-dependencies]

clade/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "clade"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+prost = "0.12"
+tonic = "0.10"
+
+[build-dependencies]
+tonic-build = "0.10"

clade/build.rs

@@ -0,0 +1,13 @@
+use std::env;
+use std::path::PathBuf;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+    tonic_build::configure()
+        .file_descriptor_set_path(out_dir.join("clade_descriptor.bin"))
+        .build_server(true)
+        .build_client(true)
+        .compile(&["proto/schema.proto"], &["proto"])?;
+
+    Ok(())
+}

clade/proto/schema.proto

@@ -0,0 +1,26 @@
+syntax = "proto3";
+
+package clade.schema;
+
+message SchemaObject {
+  string name = 1;
+  repeated TableObject tables = 2;
+}
+
+message TableObject {
+  string name = 1;
+  string location = 2;
+}
+
+message ListSchemaRequest {
+  string catalog_name = 1;
+}
+
+message ListSchemaResponse {
+  repeated SchemaObject schemas = 1;
+}
+
+service SchemaStoreService {
+  // List the available schemas
+  rpc ListSchemas(ListSchemaRequest) returns (ListSchemaResponse);
+}

clade/src/lib.rs

@@ -0,0 +1,5 @@
+pub mod schema {
+    tonic::include_proto!("clade.schema");
+    pub const FILE_DESCRIPTOR_SET: &[u8] =
+        tonic::include_file_descriptor_set!("clade_descriptor");
+}