Improve Rust SDK build flags / reduce dependencies.

This reduces the amount of dependencies in case not all features are
being used. E.g. tonic is only needed if using gRPC and pbjson,
pbjson-types and serde are only needed if using the JSON serialization.

api/rust/Cargo.toml

@@ -9,21 +9,22 @@ repository = "https://github.com/chirpstack/chirpstack"
 edition = "2021"
 
 [features]
-default = ["api"]
+default = ["api", "json"]
 api = ["tonic/transport", "tonic-build/transport", "tokio"]
+json = ["pbjson", "pbjson-types", "serde"]
 internal = []
 
 [dependencies]
 prost = "0.11"
 prost-types = "0.11"
-pbjson = "0.5"
-pbjson-types = "0.5"
 hex = "0.4"
 rand = "0.8"
 
-tonic = { version = "0.8", features = ["codegen", "prost"], default-features = false }
+tonic = { version = "0.8", features = ["codegen", "prost"], default-features = false, optional = true }
 tokio = { version = "1.25", features = ["macros"], optional = true }
-serde = { version = "1.0" }
+pbjson = { version = "0.5", optional = true }
+pbjson-types = { version = "0.5", optional = true }
+serde = { version = "1.0", optional = true }
 
 [build-dependencies]
 tonic-build = { version = "0.8", features = ["prost"], default-features = false }

api/rust/build.rs

@@ -16,12 +16,18 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     std::fs::create_dir_all(out_dir.join("meta")).unwrap();
     std::fs::create_dir_all(out_dir.join("api")).unwrap();
 
+    #[cfg(feature = "json")]
+    let well_known_types_path = "::pbjson_types";
+
+    #[cfg(not(feature = "json"))]
+    let well_known_types_path = "::prost_types";
+
     // common
     tonic_build::configure()
         .out_dir(out_dir.join("common"))
         .file_descriptor_set_path(out_dir.join("common").join("proto_descriptor.bin"))
         .compile_well_known_types(true)
-        .extern_path(".google.protobuf", "::pbjson_types")
+        .extern_path(".google.protobuf", well_known_types_path)
         .compile(
             &[cs_dir.join("common").join("common.proto").to_str().unwrap()],
             &[
@@ -30,18 +36,21 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             ],
         )?;
 
-    let descriptor_set = std::fs::read(out_dir.join("common").join("proto_descriptor.bin"))?;
-    pbjson_build::Builder::new()
-        .register_descriptors(&descriptor_set)?
-        .out_dir(out_dir.join("common"))
-        .build(&[".common"])?;
+    #[cfg(feature = "json")]
+    {
+        let descriptor_set = std::fs::read(out_dir.join("common").join("proto_descriptor.bin"))?;
+        pbjson_build::Builder::new()
+            .register_descriptors(&descriptor_set)?
+            .out_dir(out_dir.join("common"))
+            .build(&[".common"])?;
+    }
 
     // gw
     tonic_build::configure()
         .out_dir(out_dir.join("gw"))
         .file_descriptor_set_path(out_dir.join("gw").join("proto_descriptor.bin"))
         .compile_well_known_types(true)
-        .extern_path(".google.protobuf", "::pbjson_types")
+        .extern_path(".google.protobuf", well_known_types_path)
         .extern_path(".common", "crate::common")
         .compile(
             &[cs_dir.join("gw").join("gw.proto").to_str().unwrap()],
@@ -51,19 +60,22 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             ],
         )?;
 
-    let descriptor_set = std::fs::read(out_dir.join("gw").join("proto_descriptor.bin"))?;
-    pbjson_build::Builder::new()
-        .register_descriptors(&descriptor_set)?
-        .out_dir(out_dir.join("gw"))
-        .extern_path(".common", "crate::common")
-        .build(&[".gw"])?;
+    #[cfg(feature = "json")]
+    {
+        let descriptor_set = std::fs::read(out_dir.join("gw").join("proto_descriptor.bin"))?;
+        pbjson_build::Builder::new()
+            .register_descriptors(&descriptor_set)?
+            .out_dir(out_dir.join("gw"))
+            .extern_path(".common", "crate::common")
+            .build(&[".gw"])?;
+    }
 
     // internal
     tonic_build::configure()
         .out_dir(out_dir.join("internal"))
         .file_descriptor_set_path(out_dir.join("internal").join("proto_descriptor.bin"))
         .compile_well_known_types(true)
-        .extern_path(".google.protobuf", "::pbjson_types")
+        .extern_path(".google.protobuf", well_known_types_path)
         .extern_path(".common", "crate::common")
         .compile(
             &[cs_dir
@@ -77,19 +89,22 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             ],
         )?;
 
-    let descriptor_set = std::fs::read(out_dir.join("internal").join("proto_descriptor.bin"))?;
-    pbjson_build::Builder::new()
-        .register_descriptors(&descriptor_set)?
-        .out_dir(out_dir.join("internal"))
-        .extern_path(".common", "crate::common")
-        .build(&[".internal"])?;
+    #[cfg(feature = "json")]
+    {
+        let descriptor_set = std::fs::read(out_dir.join("internal").join("proto_descriptor.bin"))?;
+        pbjson_build::Builder::new()
+            .register_descriptors(&descriptor_set)?
+            .out_dir(out_dir.join("internal"))
+            .extern_path(".common", "crate::common")
+            .build(&[".internal"])?;
+    }
 
     // integration
     tonic_build::configure()
         .out_dir(out_dir.join("integration"))
         .file_descriptor_set_path(out_dir.join("integration").join("proto_descriptor.bin"))
         .compile_well_known_types(true)
-        .extern_path(".google.protobuf", "::pbjson_types")
+        .extern_path(".google.protobuf", well_known_types_path)
         .extern_path(".common", "crate::common")
         .extern_path(".gw", "crate::gw")
         .compile(
@@ -104,14 +119,18 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             ],
         )?;
 
-    let descriptor_set = std::fs::read(out_dir.join("integration").join("proto_descriptor.bin"))?;
-    pbjson_build::Builder::new()
-        .emit_fields()
-        .register_descriptors(&descriptor_set)?
-        .out_dir(out_dir.join("integration"))
-        .extern_path(".common", "crate::common")
-        .extern_path(".gw", "crate::gw")
-        .build(&[".integration"])?;
+    #[cfg(feature = "json")]
+    {
+        let descriptor_set =
+            std::fs::read(out_dir.join("integration").join("proto_descriptor.bin"))?;
+        pbjson_build::Builder::new()
+            .emit_fields()
+            .register_descriptors(&descriptor_set)?
+            .out_dir(out_dir.join("integration"))
+            .extern_path(".common", "crate::common")
+            .extern_path(".gw", "crate::gw")
+            .build(&[".integration"])?;
+    }
 
     // meta
     tonic_build::configure()
@@ -125,13 +144,16 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             &[proto_dir.join("chirpstack").to_str().unwrap()],
         )?;
 
-    let descriptor_set = std::fs::read(out_dir.join("meta").join("proto_descriptor.bin"))?;
-    pbjson_build::Builder::new()
-        .register_descriptors(&descriptor_set)?
-        .out_dir(out_dir.join("meta"))
-        .extern_path(".common", "crate::common")
-        .extern_path(".gw", "crate::gw")
-        .build(&[".meta"])?;
+    #[cfg(feature = "json")]
+    {
+        let descriptor_set = std::fs::read(out_dir.join("meta").join("proto_descriptor.bin"))?;
+        pbjson_build::Builder::new()
+            .register_descriptors(&descriptor_set)?
+            .out_dir(out_dir.join("meta"))
+            .extern_path(".common", "crate::common")
+            .extern_path(".gw", "crate::gw")
+            .build(&[".meta"])?;
+    }
 
     // api
     tonic_build::configure()

api/rust/src/common.rs

@@ -2,7 +2,8 @@ use std::error::Error;
 use std::fmt;
 use std::str::FromStr;
 
-tonic::include_proto!("common/common");
+include!(concat!(env!("OUT_DIR"), "/common/common.rs"));
+#[cfg(feature = "json")]
 include!(concat!(env!("OUT_DIR"), "/common/common.serde.rs"));
 
 #[allow(clippy::from_over_into)]

api/rust/src/gw.rs

@@ -2,7 +2,8 @@ use rand::Rng;
 use std::error::Error;
 use std::str::FromStr;
 
-tonic::include_proto!("gw/gw");
+include!(concat!(env!("OUT_DIR"), "/gw/gw.rs"));
+#[cfg(feature = "json")]
 include!(concat!(env!("OUT_DIR"), "/gw/gw.serde.rs"));
 
 #[allow(clippy::from_over_into)]

api/rust/src/integration.rs

@@ -1,4 +1,5 @@
-tonic::include_proto!("integration/integration");
+include!(concat!(env!("OUT_DIR"), "/integration/integration.rs"));
+#[cfg(feature = "json")]
 include!(concat!(
     env!("OUT_DIR"),
     "/integration/integration.serde.rs"

api/rust/src/internal.rs

@@ -1,2 +1,3 @@
-tonic::include_proto!("internal/internal");
+include!(concat!(env!("OUT_DIR"), "/internal/internal.rs"));
+#[cfg(feature = "json")]
 include!(concat!(env!("OUT_DIR"), "/internal/internal.serde.rs"));

api/rust/src/meta.rs

@@ -1,2 +1,3 @@
-tonic::include_proto!("meta/meta");
+include!(concat!(env!("OUT_DIR"), "/meta/meta.rs"));
+#[cfg(feature = "json")]
 include!(concat!(env!("OUT_DIR"), "/meta/meta.serde.rs"));