评测机
Go to file
2020-04-01 18:24:46 +08:00
.github/workflows update build.yml 2020-04-01 18:24:46 +08:00
cmd/executorserver Add c interface to executor server 2020-04-01 01:03:16 -04:00
file Refactor & Documentation 2020-03-03 02:32:59 -05:00
pkg Fix typos 2020-03-27 18:59:47 -04:00
.dockerignore Add demo Dockerfile 2020-03-04 17:45:48 -05:00
.gitignore Add c interface to executor server 2020-04-01 01:03:16 -04:00
Dockerfile.exec Add configuration for container mount points 2020-03-27 18:14:57 -04:00
executor_server.h Add c interface to executor server 2020-04-01 01:03:16 -04:00
go.mod Add c interface to executor server 2020-04-01 01:03:16 -04:00
go.sum Add c interface to executor server 2020-04-01 01:03:16 -04:00
LICENSE Initial commit 2019-08-24 15:32:38 -07:00
mount.yaml Fix typos 2020-03-27 18:59:47 -04:00
README.md Add c interface to executor server 2020-04-01 01:03:16 -04:00

go-judge

GoDoc Go Report Card Release Build

Executor Service

A rest service to run program in restricted environment and it is basically a wrapper for pkg/envexec to run single / multiple programs.

  • /run POST execute program in the restricted environment
  • /file GET list all cached file
  • /file POST prepare a file in the executor service (in memory), returns fileId (can be referenced in /run parameter)
  • /file/:fileId GET downloads file from executor service (in memory), returns file content
  • /file/:fileId DELETE delete file specified by fileId
  • /ws WebSocket for /run

Install & Run Developing Server

Install GO 1.13+ from download

go get github.com/criyle/go-judge/cmd/executorserver
sudo ~/go/bin/executorserver # or executorserver if $(GOPATH)/bin is in your $PATH

Or, by docker

docker run -it --rm --privileged -p 5050:5050 criyle/executorserver:demo

Build by your own docker build -t executorserver -f Dockerfile.exec .

The executorserver need root privilege to create cgroup. Either creates sub-directory /sys/fs/cgroup/cpuacct/go-judger, /sys/fs/cgroup/memory/go-judger, /sys/fs/cgroup/pids/go-judger and make execution user readable or use sudo to run it.

The default binding address for the executor server is :5050. Can be specified with -http flag.

The default concurrency is 4, Can be specified with -parallism flag.

The default file store is in memory, local cache can be specified with -dir flag.

The default log level is debug, use -silent to disable logs.

Build Shared object

Build container init cinit:

go build -o cinit ./cmd/cinit

Build executor_server.so:

go build -buildmode=c-shared -o executor_server.so ./cmd/executorserver/

For example, in JavaScript, run with ffi-napi:

var ffi = require('ffi-napi');

var executor_server = ffi.Library('./executor_server.so', {
    'Init': ['int', ['string']],
    'Exec': ['string', ['string']]
});

if (executor_server.Init(JSON.stringify({
    cinitPath: "/judge/cinit",
    parallism: 4,
}))) {
    console.log("Failed to init executor server");
}

const result = JSON.parse(executor_server.Exec(JSON.stringify({
    "cmd": [{
        "args": ["/bin/cat", "test.txt"],
        "env": ["PATH=/usr/bin:/bin"],
        "files": [{
            "content": ""
        }, {
            "name": "stdout",
            "max": 10240
        }, {
            "name": "stderr",
            "max": 10240
        }],
        "cpuLimit": 10000000000,
        "memoryLimit": 104857600,
        "procLimit": 50,
        "copyIn": {
            "test.txt": {
                "content": "TEST"
            }
        }
    }]
})));
console.log(result);

Output:

{
  requestId: '',
  results: [
    {
      status: 'Accepted',
      exitStatus: 0,
      time: 814048,
      memory: 253952,
      files: [Object]
    }
  ]
}

Container Root Filesystem

  • necessary lib / exec / compiler / header readonly bind mounted from current file system: /lib /lib64 /bin /usr
  • work directory tmpfs mount: /w (work dir), /tmp (compiler temp files)

The following mounts point are examples that can be configured through config file later

  • additional compiler scripts / exec readonly bind mounted: /c
  • additional header readonly bind mounted: /i

Utilities

  • pkg/envexec: run single / group of programs in parallel within restricted environment and resource constraints
  • pkg/pool: reference implementation for Cgroup & Environment Pool

API interface

interface LocalFile {
    src: string; // absolute path for the file
}

interface MemoryFile {
    content: string | Buffer; // file contents
}

interface PreparedFile {
    fileId: string; // fileId defines file uploaded by /file
}

interface Pipe {
    name: string; // file name in copyOut
    max: number;  // maximum bytes to collect from pipe
}

interface Cmd {
    args: string[]; // command line argument
    env?: string[]; // environment

    // specifies file input / pipe collector for program file descriptors
    files?: (LocalFile | MemoryFile | PreparedFile | Pipe | null)[];

    // limitations
    cpuLimit?: number;     // ns
    realCpuLimit?: number; // ns
    memoryLimit?: number;  // byte
    procLimit?: number;

    // copy the correspond file to the container dst path
    copyIn?: {[dst:string]:LocalFile | MemoryFile | PreparedFile};

    // copy out specifies files need to be copied out from the container after execution
    copyOut?: string[];
    // similar to copyOut but stores file in executor service and returns fileId, later download through /file/:fileId
    copyOutCached?: string[];
    // specifies the directory to dump container /w content
    copyOutDir: string
}

enum Status {
    Accepted,            // normal
    MemoryLimitExceeded, // mle
    TimeLimitExceeded,   // tle
    OutputLimitExceeded, // ole
    FileError,           // fe
    RuntimeError,        // re
    DangerousSyscall,    // dgs
    InternalError,       // system error
}

interface PipeIndex {
    index: number; // the index of cmd
    fd: number;    // the fd number of cmd
}

interface PipeMap {
    in: PipeIndex;  // input end of the pipe
    out: PipeIndex; // output end of the pipe
}

interface Request {
    requestId?: string; // for WebSocket requests
    cmd: Cmd[];
    pipeMapping: PipeMap[];
}

interface Result {
    status: Status;
    error?: string; // potential system error message
    time: number;   // ns
    memory: number; // byte
    // copyFile name -> content
    files?: {[name:string]:string};
    // copyFileCached name -> fileId
    fileIds?: {[name:string]:string};
}

// WebSocket results
interface WSResult {
    requestId: string;
    results: []Result;
    error?: string;
}

Example Request & Response

Single (this example require apt install g++ inside the container):

{
    "cmd": [{
        "args": ["/usr/bin/g++", "a.cc", "-o", "a"],
        "env": ["PATH=/usr/bin:/bin"],
        "files": [{
            "content": ""
        }, {
            "name": "stdout",
            "max": 10240
        }, {
            "name": "stderr",
            "max": 10240
        }],
        "cpuLimit": 10000000000,
        "memoryLimit": 104857600,
        "procLimit": 50,
        "copyIn": {
            "a.cc": {
                "content": "#include <iostream>\nusing namespace std;\nint main() {\nint a, b;\ncin >> a >> b;\ncout << a + b << endl;\n}"
            }
        },
        "copyOut": ["stdout", "stderr"],
        "copyOutCached": ["a.cc", "a"],
        "copyOutDir": "1"
    }]
}
[
    {
        "status": "Accepted",
        "exitStatus": 0,
        "time": 303225231,
        "memory": 32243712,
        "files": {
            "stderr": "",
            "stdout": ""
        },
        "fileIds": {
            "a": "5LWIZAA45JHX4Y4Z",
            "a.cc": "NOHPGGDTYQUFRSLJ"
        }
    }
]

Multiple (interaction problem):

{
    "cmd": [{
        "args": ["/bin/cat", "1"],
        "env": ["PATH=/usr/bin:/bin"],
        "files": [{
            "content": ""
        }, null, {
            "name": "stderr",
            "max": 10240
        }],
        "cpuLimit": 1000000000,
        "memoryLimit": 1048576,
        "procLimit": 50,
        "copyIn": {
            "1": { "content": "TEST 1" }
        },
        "copyOut": ["stderr"]
    },
    {
        "args": ["/bin/cat"],
        "env": ["PATH=/usr/bin:/bin"],
        "files": [null, {
            "name": "stdout",
            "max": 10240
        }, {
            "name": "stderr",
            "max": 10240
        }],
        "cpuLimit": 1000000000,
        "memoryLimit": 1048576,
        "procLimit": 50,
        "copyOut": ["stdout", "stderr"]
    }],
    "pipeMapping": [{
        "in" : {"index": 0, "fd": 1 },
        "out" : {"index": 1, "fd" : 0 }
    }]
}
[
    {
        "status": "Accepted",
        "exitStatus": 0,
        "time": 1545123,
        "memory": 253952,
        "files": {
            "stderr": ""
        },
        "fileIds": {}
    },
    {
        "status": "Accepted",
        "exitStatus": 0,
        "time": 1501463,
        "memory": 253952,
        "files": {
            "stderr": "",
            "stdout": "TEST 1"
        },
        "fileIds": {}
    }
]

TODO

  • Github actions to auto build
  • Configure mounts using YAML config file
  • Investigate root-free running mechanism (no cgroup && not set uid / gid)
  • Investigate RLimit settings (cpu, data, fsize, stack, noFile)
  • Add WebSocket for job submission