Add migration commands for SQLite; not PGSql

cmake/scripts/cppbessotDbActionClone.cmake

@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.16)
+
+function(cppbessot_db_action_target_exists out_var backend sqlite_path pgsql_connstr)
+  if("${backend}" STREQUAL "sqlite")
+    if(EXISTS "${sqlite_path}")
+      set(${out_var} TRUE PARENT_SCOPE)
+    else()
+      set(${out_var} FALSE PARENT_SCOPE)
+    endif()
+    return()
+  endif()
+
+  cppbessot_db_action_find_program_or_fail(_psql psql
+    "PostgreSQL live actions require `psql` to be available in PATH.")
+  execute_process(
+    COMMAND "${_psql}" "${pgsql_connstr}" -v ON_ERROR_STOP=1 -c "SELECT 1;"
+    RESULT_VARIABLE _result
+    OUTPUT_QUIET
+    ERROR_QUIET
+  )
+  if(_result EQUAL 0)
+    set(${out_var} TRUE PARENT_SCOPE)
+  else()
+    set(${out_var} FALSE PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(cppbessot_db_action_get_clone_command out_var backend)
+  if("${backend}" STREQUAL "sqlite")
+    set(_command "${CPPBESSOT_DB_SQLITE_CLONE_PROD_TO_PRODDEV_COMMAND}")
+  else()
+    set(_command "${CPPBESSOT_DB_PGSQL_CLONE_PROD_TO_PRODDEV_COMMAND}")
+  endif()
+  set(${out_var} "${_command}" PARENT_SCOPE)
+endfunction()
+
+function(cppbessot_db_action_invoke_clone_hook backend)
+  cppbessot_db_action_get_clone_command(_clone_command "${backend}")
+  if("${_clone_command}" STREQUAL "")
+    message(FATAL_ERROR
+      "No clone command is configured for backend `${backend}` while preparing proddev.")
+  endif()
+
+  execute_process(
+    COMMAND sh -c "${_clone_command}"
+    RESULT_VARIABLE _result
+    OUTPUT_VARIABLE _stdout
+    ERROR_VARIABLE _stderr
+  )
+
+  if(NOT _result EQUAL 0)
+    message(FATAL_ERROR
+      "Proddev clone command failed for backend `${backend}`.\n${_stdout}\n${_stderr}")
+  endif()
+endfunction()
+
+function(cppbessot_db_action_prepare_proddev target backend use_stale sqlite_path pgsql_connstr)
+  if(NOT "${target}" STREQUAL "proddev")
+    return()
+  endif()
+
+  if(use_stale)
+    cppbessot_db_action_target_exists(_exists "${backend}" "${sqlite_path}" "${pgsql_connstr}")
+    if(NOT _exists)
+      message(FATAL_ERROR
+        "DB_MIGRATE_PRODDEV_USE_STALE is ON, but no current stale proddev target exists.")
+    endif()
+    return()
+  endif()
+
+  cppbessot_db_action_invoke_clone_hook("${backend}")
+  cppbessot_db_action_target_exists(_exists "${backend}" "${sqlite_path}" "${pgsql_connstr}")
+  if(NOT _exists)
+    message(FATAL_ERROR
+      "Proddev clone command completed, but the proddev target still does not appear to exist.")
+  endif()
+endfunction()