Configurable drogon_ctl location

[gav2xlin]

Hello. Please make the location of the drogon_ctl command configurable from CMake scripts directly.

https://cmake.org/cmake/help/latest/command/find_program.html

https://cmake.org/cmake/help/latest/variable/CMAKE_PROGRAM_PATH.html

Semicolon-separated list of directories specifying a search path for the find_program() command. By default it is empty, it is intended to be set by the project.

The Drogon library is not always installed on the system so that the path to the drogon_ctl command globally set in the PATH environment variable. At the same time, the CMAKE_PROGRAM_PATH variable is configurable from CMake scripts.

https://github.com/drogonframework/drogon/blob/master/cmake/DrogonUtilities.cmake

I'm considering a scenario where the Drogon library is installed by package managers such as Conan which creates its own environment.

From my system:
~/.conan2$ find . -iname 'drogon_ctl' ./p/b/drogoa449f6147cb12/p/bin/drogon_ctl ./p/b/drogoa449f6147cb12/b/build/Release/drogon_ctl ./p/b/drogoa449f6147cb12/b/build/Release/drogon_ctl/drogon_ctl ./p/b/drogoa449f6147cb12/b/src/drogon_ctl ./p/b/drogo79535e018a23d/p/bin/drogon_ctl ./p/b/drogo79535e018a23d/b/build/Debug/drogon_ctl ./p/b/drogo79535e018a23d/b/build/Debug/drogon_ctl/drogon_ctl ./p/b/drogo79535e018a23d/b/src/drogon_ctl ./p/drogo60067c88c49b2/s/src/drogon_ctl

This has been fixed. Hence, this script is included automatically in the builds, but the drogon_create_views() function still does not work because it is impossible to configure the path to this command anywhere 🤔

./p/b/drogoa449f6147cb12/p/lib/cmake/Drogon/DrogonUtilities.cmake
./p/b/drogoa449f6147cb12/b/src/cmake/DrogonUtilities.cmake
./p/b/drogo79535e018a23d/p/lib/cmake/Drogon/DrogonUtilities.cmake
./p/b/drogo79535e018a23d/b/src/cmake/DrogonUtilities.cmake
./p/drogo60067c88c49b2/s/src/cmake/DrogonUtilities.cmake

[gav2xlin]

I've tested my change, but I use Conan

find_program(DROGON_CTL drogon_ctl REQUIRED) message(STATUS "DROGON_CTL ${DROGON_CTL}")

conan install -r conancenter --update . --build=missing

conan install . --build=missing

and

cmake --preset conan-release -DCMAKE_VERBOSE_MAKEFILE=ON
cmake --build --preset conan-release

The first command prints this
-- DROGON_CTL /home/gav2xlin/.conan2/p/b/drogo038e8a0079189/p/bin/drogon_ctl

from this project https://github.com/PacktPublishing/Software-Architecture-with-Cpp-2E/tree/ch12-drogon-ctl/Chapter12/customer

$ find . -iname 'greet*'
./build/Release/src/customer/CMakeFiles/customer.dir/greet.cc.o
./build/Release/src/customer/CMakeFiles/customer.dir/greet.cc.o.d
./build/Release/src/customer/greet.h
./build/Release/src/customer/greet.cc
./src/customer/views/greet.csp

Chapter12/customer/src/customer/CMakeLists.txt

drogon_create_views(customer ${CMAKE_CURRENT_SOURCE_DIR}/views/
                    ${CMAKE_CURRENT_BINARY_DIR})

build/Release/generators/CMakePresets.json
"configurePresets": [ { "name": "conan-release", "displayName": "'conan-release' config", "description": "'conan-release' configure using 'Unix Makefiles' generator", "generator": "Unix Makefiles", "cacheVariables": { "CMAKE_POLICY_DEFAULT_CMP0091": "NEW", "CMAKE_BUILD_TYPE": "Release" }, "environment": { "PATH": "/home/gav2xlin/.conan2/p/b/drogo038e8a0079189/p/bin:$penv{PATH}", "LD_LIBRARY_PATH": "/home/gav2xlin/.conan2/p/b/drogo038e8a0079189/p/lib:$penv{LD_LIBRARY_PATH}", "DYLD_LIBRARY_PATH": "/home/gav2xlin/.conan2/p/b/drogo038e8a0079189/p/lib:$penv{DYLD_LIBRARY_PATH}" }, "toolchainFile": "generators/conan_toolchain.cmake", "binaryDir": "/home/gav2xlin/Book/Software-Architecture-with-Cpp-2E/Chapter12/customer/build/Release" } ],

drogon_ctl is compiled and installed here
/home/gav2xlin/.conan2/p/b/drogo038e8a0079189/p/bin

In your tests and builds, find_program(DROGON_CTL drogon_ctl REQUIRED) is called before the drogon_ctl command is built and installed 🤔