[MDB-26086]: Introduce conditional python3 dependency for different d…

…istributions (#86)

Makefile

@@ -88,7 +88,7 @@ clean-pycache:
 .PHONY: install
 install:
 	@echo "Installing into $(INSTALL_DIR)"
-	python3.6 -m venv $(INSTALL_DIR)
+	$(PYTHON) -m venv $(INSTALL_DIR)
 	$(INSTALL_DIR)/bin/pip install -r requirements.txt
 	$(INSTALL_DIR)/bin/pip install .
 	mkdir -p $(DESTDIR)/usr/bin/

debian/control

@@ -2,13 +2,13 @@ Source: ch-backup
 Section: database
 Priority: optional
 Maintainer: Yandex LLC
-Build-Depends: debhelper (>= 8.0.0), python3.6, python3.6-venv, python3-pip
+Build-Depends: debhelper (>= 8.0.0), python3 (>= 3.6), python3-venv, python3-pip
 Standards-Version: 3.9.4
 Homepage: https://github.com/yandex/ch-backup
 Vcs-Browser: https://github.com/yandex/ch-backup.git
 Vcs-Git: git://github.com:yandex/ch-backup.git
 
 Package: ch-backup
 Architecture: any
-Depends: python3.6
+Depends: ${python:Depends}
 Description: Backup tool for ClickHouse DBMS.

debian/rules

@@ -1,9 +1,24 @@
 #!/usr/bin/make -f
 # -*- makefile -*-
 
+PYTHON_MAJOR := $(shell $(PYTHON) -c 'import sys; print(sys.version_info[0])')
+PYTHON_MINOR := $(shell $(PYTHON) -c 'import sys; print(sys.version_info[1])')
+
+PYTHON_FROM := $(PYTHON_MAJOR).$(PYTHON_MINOR)
+PYTHON_TO := $(PYTHON_MAJOR).$(shell echo $$(( $(PYTHON_MINOR) + 1 )))
+
+# Use conditional python3 dependency because package for Bionic requires python3.6,
+# but package for Jammy requires python3.10.
+# All this is due to the fact that we put the entire virtual environment in a deb package
+# and that venv links to the system python
+SUBSTVARS := -Vpython:Depends="python3 (>= $(PYTHON_FROM)), python3 (<< $(PYTHON_TO))"
+
 %:
 	dh $@
 
+override_dh_gencontrol:
+	dh_gencontrol -- $(SUBSTVARS)
+
 override_dh_auto_clean:
 
 override_dh_strip: