github.com/m3db/m3@v1.5.0/src/x/debug/host.go (about)

     1  // Copyright (c) 2019 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package debug
    22  
    23  import (
    24  	"encoding/json"
    25  	"io"
    26  	"net/http"
    27  	"os"
    28  )
    29  
    30  // hostInfoSource is Source implementation returning data about the underlying host:
    31  // PID, working directory, etc.
    32  type hostInfoSource struct{}
    33  
    34  type hostInfo struct {
    35  	PID int    `json:"pid"`
    36  	CWD string `json:"cwd"`
    37  }
    38  
    39  // NewHostInfoSource returns a Source for host information
    40  func NewHostInfoSource() Source {
    41  	return &hostInfoSource{}
    42  }
    43  
    44  // Write fetches data about the host and writes it in the given writer.
    45  // The data is formatted in json.
    46  // It will return an error if it can't get working directory or marshal.
    47  func (h *hostInfoSource) Write(w io.Writer, _ *http.Request) error {
    48  	wd, err := os.Getwd()
    49  	if err != nil {
    50  		return err
    51  	}
    52  	hostInfo := &hostInfo{
    53  		PID: os.Getpid(),
    54  		CWD: wd,
    55  	}
    56  	jsonData, err := json.MarshalIndent(hostInfo, "", "  ")
    57  	if err != nil {
    58  		return err
    59  	}
    60  	w.Write(jsonData)
    61  	return nil
    62  }