github.com/m3db/m3@v1.5.0/src/cmd/tools/m3ctl/yaml/load.go (about)

     1  // Copyright (c) 2020 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 yaml
    22  
    23  import (
    24  	"bytes"
    25  	"go.uber.org/zap"
    26  	"io"
    27  	"io/ioutil"
    28  
    29  	"github.com/gogo/protobuf/jsonpb"
    30  	"github.com/gogo/protobuf/proto"
    31  )
    32  
    33  // Load reads a yaml representation of an m3 structure
    34  // and produces an io.Reader of it protocol buffer-encoded
    35  //
    36  // we don't know anything about what the user it trying to do
    37  // so peek at it to see what's the intended action then load it
    38  //
    39  // See the examples directories.
    40  //
    41  func Load(path string, zl *zap.Logger) (string, io.Reader, error) {
    42  	content, err := ioutil.ReadFile(path)
    43  	if err != nil {
    44  		return "", nil, err
    45  	}
    46  	url, pbmessage, err := peeker(content)
    47  	if err != nil {
    48  		return "", nil, err
    49  	}
    50  	rv, err := load(pbmessage)
    51  	return url, rv, nil
    52  }
    53  
    54  func load(target proto.Message) (io.Reader, error) {
    55  	// marshal it into protocol buffers
    56  	var data *bytes.Buffer
    57  	data = bytes.NewBuffer(nil)
    58  	marshaller := &jsonpb.Marshaler{}
    59  	if err := marshaller.Marshal(data, target); err != nil {
    60  		return nil, err
    61  	}
    62  	return data, nil
    63  }