sandboxed-api/contrib/jsonnet/examples/jsonnet_multiple_files_example.cc
Christian Blichmann ee5ebaa48f CMake: Make it easier for projects to consume sandboxed libraries
This change starts with Jsonnet as the canonical, ready-made sandboxed library
example. Follow-up changes should similarly migrate the OSS Internship
sandboxes.

- Add an `add_sapi_subdirectory()` which sets up source and binary directories
  correctly when consuming SAPI as sub-project
- Restructure the Jsonnet `CMakeLists.txt` and simplify header inclusions
- Update the Jsonnet README file

PiperOrigin-RevId: 425818479
Change-Id: Iba9e83201863b4ad8a91914397b310d9d4230423
2022-02-02 01:09:56 -08:00

131 lines
4.3 KiB
C++

// Copyright 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <libgen.h>
#include <syscall.h>
#include <cstdlib>
#include <iostream>
#include "jsonnet_sapi.sapi.h" // NOLINT(build/include)
#include "sandboxed_api/util/fileops.h"
#include "sandboxed_api/util/path.h"
class JsonnetSapiSandbox : public JsonnetSandbox {
public:
explicit JsonnetSapiSandbox(std::string in_file, std::string out_directory)
: in_file_(std::move(in_file)),
out_directory_(std::move(out_directory)) {}
// We need a slightly different policy than the default one
std::unique_ptr<sandbox2::Policy> ModifyPolicy(
sandbox2::PolicyBuilder*) override {
return sandbox2::PolicyBuilder()
.AllowStaticStartup()
.AllowOpen()
.AllowRead()
.AllowWrite()
.AllowStat()
.AllowSystemMalloc()
.AllowExit()
.AllowSyscalls({
__NR_futex,
__NR_close,
})
.AddDirectoryAt(sapi::file::CleanPath(&out_directory_[0]), "/output",
/*is_ro=*/false)
.AddDirectoryAt(dirname(&in_file_[0]), "/input", true)
.BuildOrDie();
}
private:
std::string in_file_;
std::string out_directory_;
};
absl::Status JsonnetMain(std::string in_file, std::string out_file) {
using sapi::file::JoinPath;
using sapi::file_util::fileops::Basename;
// Initialize sandbox.
JsonnetSapiSandbox sandbox(in_file, out_file);
SAPI_RETURN_IF_ERROR(sandbox.Init())
JsonnetApi api(&sandbox);
// Initialize library's main structure.
SAPI_ASSIGN_OR_RETURN(JsonnetVm * jsonnet_vm, api.c_jsonnet_make());
sapi::v::RemotePtr vm_pointer(jsonnet_vm);
// Read input file.
std::string in_file_in_sandboxee(JoinPath("/input", Basename(in_file)));
sapi::v::ConstCStr in_file_var(in_file_in_sandboxee.c_str());
SAPI_ASSIGN_OR_RETURN(char* input,
api.c_read_input(false, in_file_var.PtrBefore()));
// Process jsonnet data.
sapi::v::RemotePtr input_pointer(input);
sapi::v::Int error;
SAPI_ASSIGN_OR_RETURN(char* output, api.c_jsonnet_evaluate_snippet_multi(
&vm_pointer, in_file_var.PtrBefore(),
&input_pointer, error.PtrAfter()));
CHECK(!error.GetValue()) << "Jsonnet code evaluation failed: "
<< error.GetValue() << "\n"
<< "Make sure all files used by your jsonnet file "
"are in the same directory as your file.";
// Write data to file.
std::string out_file_in_sandboxee(JoinPath("/output", Basename(out_file)));
sapi::v::ConstCStr out_file_var(out_file_in_sandboxee.c_str());
sapi::v::RemotePtr output_pointer(output);
SAPI_ASSIGN_OR_RETURN(
bool success,
api.c_write_output_file(&output_pointer, out_file_var.PtrBefore()));
CHECK(success) << "Writing to output file failed: " << success;
// Clean up.
SAPI_ASSIGN_OR_RETURN(char* result,
api.c_jsonnet_realloc(&vm_pointer, &output_pointer, 0));
SAPI_RETURN_IF_ERROR(api.c_jsonnet_destroy(&vm_pointer));
SAPI_RETURN_IF_ERROR(api.c_free_input(&input_pointer));
return absl::OkStatus();
}
int main(int argc, char* argv[]) {
using sapi::file_util::fileops::Basename;
google::InitGoogleLogging(argv[0]);
gflags::ParseCommandLineFlags(&argc, &argv, true);
if (!(argc == 3)) {
std::cerr << "Usage:\n"
<< Basename(argv[0])
<< " /absolute/path/to/INPUT.jsonnet /absolute/path/to/OUTPUT\n";
return EXIT_FAILURE;
}
std::string in_file(argv[1]);
std::string out_file(argv[2]);
absl::Status status = JsonnetMain(in_file, out_file);
if (!status.ok()) {
LOG(ERROR) << "Failed: " << status.ToString();
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}