os_unix.go

Documentation: go.opentelemetry.io/otel/sdk/resource

     1  // Copyright The OpenTelemetry Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  //go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
    16  // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
    17  
    18  package resource // import "go.opentelemetry.io/otel/sdk/resource"
    19  
    20  import (
    21  	"fmt"
    22  	"os"
    23  
    24  	"golang.org/x/sys/unix"
    25  )
    26  
    27  type unameProvider func(buf *unix.Utsname) (err error)
    28  
    29  var defaultUnameProvider unameProvider = unix.Uname
    30  
    31  var currentUnameProvider = defaultUnameProvider
    32  
    33  func setDefaultUnameProvider() {
    34  	setUnameProvider(defaultUnameProvider)
    35  }
    36  
    37  func setUnameProvider(unameProvider unameProvider) {
    38  	currentUnameProvider = unameProvider
    39  }
    40  
    41  // platformOSDescription returns a human readable OS version information string.
    42  // The final string combines OS release information (where available) and the
    43  // result of the `uname` system call.
    44  func platformOSDescription() (string, error) {
    45  	uname, err := uname()
    46  	if err != nil {
    47  		return "", err
    48  	}
    49  
    50  	osRelease := osRelease()
    51  	if osRelease != "" {
    52  		return fmt.Sprintf("%s (%s)", osRelease, uname), nil
    53  	}
    54  
    55  	return uname, nil
    56  }
    57  
    58  // uname issues a uname(2) system call (or equivalent on systems which doesn't
    59  // have one) and formats the output in a single string, similar to the output
    60  // of the `uname` commandline program. The final string resembles the one
    61  // obtained with a call to `uname -snrvm`.
    62  func uname() (string, error) {
    63  	var utsName unix.Utsname
    64  
    65  	err := currentUnameProvider(&utsName)
    66  	if err != nil {
    67  		return "", err
    68  	}
    69  
    70  	return fmt.Sprintf("%s %s %s %s %s",
    71  		unix.ByteSliceToString(utsName.Sysname[:]),
    72  		unix.ByteSliceToString(utsName.Nodename[:]),
    73  		unix.ByteSliceToString(utsName.Release[:]),
    74  		unix.ByteSliceToString(utsName.Version[:]),
    75  		unix.ByteSliceToString(utsName.Machine[:]),
    76  	), nil
    77  }
    78  
    79  // getFirstAvailableFile returns an *os.File of the first available
    80  // file from a list of candidate file paths.
    81  func getFirstAvailableFile(candidates []string) (*os.File, error) {
    82  	for _, c := range candidates {
    83  		file, err := os.Open(c)
    84  		if err == nil {
    85  			return file, nil
    86  		}
    87  	}
    88  
    89  	return nil, fmt.Errorf("no candidate file available: %v", candidates)
    90  }
    91
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