Rust integration: Adding variables & clients.

everestrs/CMakeLists.txt

@@ -1,35 +1,83 @@
-include(cxxrs)
-
-find_program(CXXBRIDGE cxxbridge PATHS "$ENV{HOME}/.cargo/bin/")
-if (CXXBRIDGE STREQUAL "CXXBRIDGE-NOTFOUND")
-  message("Could not find cxxbridge, trying to install with `cargo install cxxbridge-cmd'")
-  find_program(CARGO cargo PATHS "$ENV{HOME}/.cargo/bin/")
-  if (CARGO STREQUAL "CARGO-NOTFOUND")
-    message(FATAL_ERROR "Requires cargo available in path, install via rustup https://rustup.rs/")
-  endif()
-  execute_process(COMMAND ${CARGO} install cxxbridge-cmd --version 1.0.107)
-  find_program(CXXBRIDGE cxxbridge PATHS "$ENV{HOME}/.cargo/bin/")
-endif()
-
-emit_cxxrs_header()
-emit_cxxrs_for_module(everestrs)
+set(CXXBRIDGE_BINARY ${CMAKE_CURRENT_BINARY_DIR}/cargo/bin/cxxbridge)
+if (NOT EXISTS ${CXXBRIDGE_BINARY})
+    message(STATUS "Fetching rust cxxbridge cli tool")
+    execute_process(
+        COMMAND
+            cargo install cxxbridge-cmd --root ${CMAKE_CURRENT_BINARY_DIR}/cargo
+        WORKING_DIRECTORY
+            ${CMAKE_CURRENT_BINARY_DIR}
+        RESULT_VARIABLE
+            CARGO_INSTALL_RESULT
+        OUTPUT_QUIET
+        ERROR_VARIABLE
+            CARGO_INSTALL_ERROR
+    )
+
+    if (CARGO_INSTALL_RESULT)
+        message(FATAL_ERROR "cargo install cxxbridge-cmd failed with:\n${CARGO_INSTALL_ERROR}")
+    endif ()
+endif ()
+
+set(CXXBRIDGE_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/cxxbridge)
+set(EVERESTRS_FFI_HEADER ${CXXBRIDGE_OUTPUT_DIR}/lib.rs.h)
+set(EVERESTRS_FFI_SOURCE ${CXXBRIDGE_OUTPUT_DIR}/lib.rs.cc)
+set(CXXBRIDGE_HEADER ${CXXBRIDGE_OUTPUT_DIR}/rust.h)
+
+add_custom_command(
+    OUTPUT
+        ${CXXBRIDGE_OUTPUT_DIR}
+        ${EVERESTRS_FFI_HEADER}
+        ${EVERESTRS_FFI_SOURCE}
+        ${CXXBRIDGE_HEADER}
+    COMMAND
+        ${CMAKE_COMMAND} -E make_directory ${CXXBRIDGE_OUTPUT_DIR}
+    COMMAND
+        ${CXXBRIDGE_BINARY} --header -o ${CXXBRIDGE_HEADER}
+    COMMAND
+        ${CXXBRIDGE_BINARY} ${CMAKE_CURRENT_SOURCE_DIR}/everestrs/src/lib.rs --header -o ${EVERESTRS_FFI_HEADER}
+    COMMAND
+        ${CXXBRIDGE_BINARY} ${CMAKE_CURRENT_SOURCE_DIR}/everestrs/src/lib.rs -o ${EVERESTRS_FFI_SOURCE}
+    DEPENDS
+        everestrs/src/lib.rs
+    COMMENT "Generating cxxbridge glue for everestrs"
+    VERBATIM
+    DEPENDS
+        ${CXXBRIDGE_BINARY}
+)
 
 add_library(everestrs_sys STATIC
-  ${CMAKE_CURRENT_BINARY_DIR}/cxxbridge/everestrs/lib.rs.cc
-  everestrs_sys/everestrs_sys.cpp
+    ${EVERESTRS_FFI_SOURCE}
+    everestrs_sys/everestrs_sys.cpp
 )
+add_library(everest::everestrs_sys ALIAS everestrs_sys)
 
-target_include_directories(everestrs_sys PRIVATE
-  ${CMAKE_CURRENT_SOURCE_DIR}
-  ${CMAKE_CURRENT_BINARY_DIR}/cxxbridge
+set_property(
+    TARGET
+        everestrs_sys
+    PROPERTY
+        EVERESTRS_DIR ${CMAKE_CURRENT_SOURCE_DIR}/everestrs
+)
+
+set_property(
+    TARGET
+        everestrs_sys
+    PROPERTY
+        EVERESTRS_DIR ${CMAKE_CURRENT_SOURCE_DIR}/everestrs
+)
+
+target_include_directories(everestrs_sys
+    PRIVATE
+        ${CMAKE_CURRENT_SOURCE_DIR}
+        ${CMAKE_CURRENT_BINARY_DIR}
 )
 
-# This is a requirement that linking works on systems enforcing PIE.
+# This is a requirement that linking works on systems enforcing PIE
+# FIXME (aw): investicate why this is really necessary
 set_property(TARGET everestrs_sys PROPERTY POSITION_INDEPENDENT_CODE ON)
 target_link_libraries(everestrs_sys
     PRIVATE
-    everest::framework
-    everest::log
+        everest::framework
+        everest::log
 )
 
 install(TARGETS everestrs_sys LIBRARY)

everestrs/everestrs/README.md

@@ -4,26 +4,30 @@
 
 ## Trying it out
 
-    - Install rust as outlined on <https://rustup.rs/>, which should just be this
-      one line: `curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh`
-    - Built your workspace as outlined in `everest-core` README, make sure to tell
-      cMake to enable `EVEREST_ENABLE_RS_SUPPORT`. Note, that the Rust code relies
-      on being built in a workspace where `make install` was run once.
-    - You can now try building the code, but it will not do anything: `cd everestrs
-      && cargo build --all`
-    - If you want to play with a node, check out `https://github.com/EVerest/everest-core/pull/344` in your workspace and run make install.
-    - Go to `everest-core/modules/RsSomkeTest` and run `cargo build` there.
-    - There is no support for building or installing Rust modules with cMake
-      currently, so let's fake the installation:
-    - Go to `everest-core/build/dist/libexec/everest/modules` and create the stuff needed for a module:
-        ~~~bash
-        mkdir RsSmokeTest
-        ln -s ../../../../../../modules/RsSmokeTest/target/debug/smoke_test RsSmokeTest
-        ln -s ../../../../../../modules/RsSmokeTest/manifest.yaml . 
-        ~~~
-    - You should now be able to configure the `RsSmokeTest` module in your config
-      YAML.
+  - Install rust as outlined on <https://rustup.rs/>, which should just be this
+    one line: `curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh`
+  - Built your workspace as outlined in `everest-core` README, make sure to tell
+    cMake to enable `EVEREST_ENABLE_RS_SUPPORT`. Note, that the Rust code relies
+    on being built in a workspace where `make install` was run once.
+  - You can now try building the code, but it will not do anything: `cd everestrs
+    && cargo build --all`
+  - You should now be able to configure the `RsExample` or `RsExampleUser` modules in your config
+    YAML.
+
+## Differences to other EVerest language wrappers
+
+  - The `enable_external_mqtt` is ignored for Rust modules. If you want to interact
+    with MQTT externally, just pull an external mqtt module (for example the
+    really excellent [rumqttc](https://docs.rs/rumqttc/latest/rumqttc/)) crate
+    into your module and use it directly. This is a concious decision to future
+    proof, should everst at some point move to something different than MQTT as
+    transport layer and for cleaner abstraction.
 
 ## Status
 
-This code is currently only supporting providing an interface to be implemented, i.e. no variables publish or receiving and no calling of other interfaces. Those features are straightforward, quick and easy to implement, but for now this is probably enough to iron out the integration questions.
+Full support for requiring and providing interfaces is implemented, missing
+currently is:
+
+  - Support for EVerest logging
+  - Support for Configuration options of Modules
+  - Support for implementations with `max_connections != 1` or `min_connections != 1`

everestrs/everestrs/build.rs

@@ -7,6 +7,10 @@ struct Libraries {
 }
 
 fn find_everest_workspace_root() -> PathBuf {
+    if let Ok(everest_framework_dir) = env::var("EVEREST_RS_FRAMEWORK_SOURCE_LOCATION") {
+        return PathBuf::from(everest_framework_dir);
+    }
+
     let mut cur_dir =
         PathBuf::from(env::var("CARGO_MANIFEST_DIR").expect("always set in build.rs execution"));
 
@@ -24,8 +28,19 @@ fn find_everest_workspace_root() -> PathBuf {
 /// Returns the Libraries path if this is a standalone build of everest-framework or None if it is
 /// not.
 fn find_libs_in_everest_framework(root: &Path) -> Option<Libraries> {
-    let everestrs_sys = root.join("everest-framework/build/everestrs/libeverestrs_sys.a");
-    let framework = root.join("everest-framework/build/lib/libframework.so");
+    let (everestrs_sys, framework) =
+        if let Ok(everest_framework_dir) = env::var("EVEREST_RS_FRAMEWORK_BINARY_LOCATION") {
+            let everest_framework_path = PathBuf::from(everest_framework_dir);
+            (
+                everest_framework_path.join("everestrs/libeverestrs_sys.a"),
+                everest_framework_path.join("lib/libframework.so"),
+            )
+        } else {
+            (
+                root.join("everest-framework/build/everestrs/libeverestrs_sys.a"),
+                root.join("everest-framework/build/lib/libframework.so"),
+            )
+        };
     if everestrs_sys.exists() && framework.exists() {
         Some(Libraries {
             everestrs_sys,