use mypy for automatic type checks in Python

This commit adds mypy [0] as build dependency and ensures it is
invoked during the package build process.

mypy can also be manually invoked via `make lint`.

A mypy.ini file [1] is also added to disable errors regarding missing
type stubs for pyVmomi and pyVim.

[0]: https://www.mypy-lang.org/
[1]: https://mypy.readthedocs.io/en/stable/config_file.html

Signed-off-by: Max Carrara <m.carrara@proxmox.com>

Makefile

@@ -28,6 +28,7 @@ BINARY = $(COMPILEDIR)/esxi-folder-fuse
 SCRIPT = listvms.py
 
 CARGO ?= cargo
+MYPY ?= mypy
 
 .PHONY: all
 all: $(BINARY)
@@ -40,8 +41,17 @@ check: test
 test:
 	$(CARGO) test $(CARGO_BUILD_ARGS)
 
+.lint-incremental: $(SCRIPT)
+	$(MYPY) $?
+	touch "$@"
+
+.PHONY: lint
+lint: $(SCRIPT)
+	$(MYPY) $(SCRIPT)
+	touch ".lint-incremental"
+
 .PHONY: install
-install: $(BINARY) $(SCRIPT)
+install: $(BINARY) $(SCRIPT) .lint-incremental
 	install -m755 -d $(DESTDIR)$(LIBEXECDIR)/pve-esxi-import-tools
 	install -m755 -t $(DESTDIR)$(LIBEXECDIR)/pve-esxi-import-tools $(BINARY)
 	install -m755 -t $(DESTDIR)$(LIBEXECDIR)/pve-esxi-import-tools $(SCRIPT)
@@ -55,6 +65,7 @@ $(BUILD_DIR):
 	cp -t $@.tmp -a \
 	  debian \
 	  Makefile \
+	  mypy.ini \
 	  listvms.py \
 	  Cargo.toml \
 	  src

debian/control

@@ -30,6 +30,7 @@ Build-Depends: cargo:native (>= 0.65.0~),
                librust-tokio-1+rt-multi-thread-dev,
                librust-tokio-1+time-dev,
                libstd-rust-dev,
+               mypy,
                rustc:native,
 Maintainer: Proxmox Support Team <support@proxmox.com>
 Standards-Version: 4.6.2

mypy.ini

@@ -0,0 +1,8 @@
+[mypy]
+
+[mypy-pyVmomi]
+ignore_missing_imports = True
+
+[mypy-pyVim.*]
+ignore_missing_imports = True
+