new docker-based build

This replaces the previous Dockerfile, which was a single stage for
building and deployment.

The new one is a multi-stage build. Its "dev" target has the full
development environment; its "deploy" target is more slim. It supports
cross-compiled builds via BuildKit, eg to prepare a build suitable for
a Raspberry Pi:

docker buildx build --load --platform=linux/arm64/v8 --tag=moonfire-nvr --progress=plain --target=deploy -f docker/Dockerfile .

Coming next: updating the installation docs.

db/build.rs

@@ -28,11 +28,14 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-fn main() {
-    protobuf_codegen_pure::Codegen::new()
-        .out_dir(".")
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    Ok(protobuf_codegen_pure::Codegen::new()
+        .out_dir(std::env::var("OUT_DIR")?)
         .inputs(&["proto/schema.proto"])
         .include("proto")
-        .run()
-        .expect("protoc");
+        .customize(protobuf_codegen_pure::Customize {
+            gen_mod_rs: Some(true),
+            ..Default::default()
+        })
+        .run()?)
 }

db/lib.rs

@@ -37,9 +37,12 @@ mod compare;
 pub mod db;
 pub mod dir;
 mod fs;
+mod proto {
+    include!(concat!(env!("OUT_DIR"), "/mod.rs"));
+}
 mod raw;
 pub mod recording;
-mod schema;
+use proto::schema;
 pub mod signal;
 pub mod upgrade;
 pub mod writer;