Stubserver re-write in Rust

.gitignore

@@ -6,3 +6,4 @@ certgen/certgen
 tlsserver/tlsserver
 .idea
 *.iml
+.DS_Store

.pre-commit-config.yaml

@@ -32,3 +32,19 @@ repos:
     rev: 5.13.2
     hooks:
       - id: isort
+  - repo: local
+    hooks:
+      - id: cargo-fmt
+        name: cargo fmt
+        entry: cargo fmt --manifest-path boltstub/Cargo.toml --
+        language: system
+        types: [rust]
+        pass_filenames: false
+  - repo: local
+    hooks:
+      - id: cargo-clippy
+        name: cargo clippy
+        entry: cargo clippy --manifest-path boltstub/Cargo.toml --all-features --tests -- -D warnings
+        language: system
+        types: [rust]
+        pass_filenames: false

CONTRIBUTING.md

@@ -5,13 +5,30 @@ Setting up the development environment:
  * Install Python 3.8+
  * Install the requirements
    ```bash
-   $ python3 -m pip install -U pip
-   $ python3 -m pip install -Ur requirements.txt
+   python3 -m pip install -U pip
+   python3 -m pip install -Ur requirements.txt
    ```
    You have to repeat this step whenever a commit adds new dependencies.
+ * Install Rust
+   ```bash
+   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
+   ```
+ * Compile and install the stubserver
+   ```bash
+   cargo install --locked --path boltstub
+   ```
+   *TIP*:  
+   When working on the stubserver, you can use `watchexec` to automatically
+   build and install it whenever you change the code:
+   ```bash
+   # only once, to install watchexec:
+   cargo install --locked [email protected]
+   # then, whenever you work on the stubserver:
+   watchexec -w boltstub -e rs cargo install --locked --path boltstub
+   ```
  * Install the pre-commit hook, that will do some code-format-checking.
    ```bash
-   $ pre-commit install
+   pre-commit install
    ```
    Note that this is not an auto-formatter. It will alter some code, but
    mostly it will just complain about non-compliant code.  
@@ -27,7 +44,7 @@ Setting up the development environment:
    `setup.cfg`.  
    If you want to run the checks manually, you can do so:
    ```bash
-   $ pre-commit run --all-files
+   pre-commit run --all-files
    # or
-   $ pre-commit run --file path/to/a/file
+   pre-commit run --file path/to/a/file
    ```

boltstub/.dockerignore

@@ -0,0 +1,2 @@
+.gitignore
+*.md

boltstub/.gitignore

@@ -0,0 +1 @@
+/target

boltstub/.rustfmt.toml

@@ -0,0 +1,2 @@
+imports_granularity = "Module"
+group_imports = "StdExternalCrate"