github.com/containers/podman/v2@v2.2.2-0.20210501105131-c1e07d070c4c/pkg/varlinkapi/funcs.go (about)

     1  package varlinkapi
     2  
     3  import (
     4  	"fmt"
     5  	"os"
     6  	"path/filepath"
     7  	"strings"
     8  
     9  	"github.com/containers/image/v5/types"
    10  	"github.com/containers/podman/v2/libpod/image"
    11  	"github.com/google/shlex"
    12  	"github.com/pkg/errors"
    13  )
    14  
    15  func GetSystemContext(authfile string) (*types.SystemContext, error) {
    16  	if authfile != "" {
    17  		if _, err := os.Stat(authfile); err != nil {
    18  			return nil, errors.Wrapf(err, "error checking authfile path %s", authfile)
    19  		}
    20  	}
    21  	return image.GetSystemContext("", authfile, false), nil
    22  }
    23  
    24  func substituteCommand(cmd string) (string, error) {
    25  	var (
    26  		newCommand string
    27  	)
    28  
    29  	// Replace cmd with "/proc/self/exe" if "podman" or "docker" is being
    30  	// used. If "/usr/bin/docker" is provided, we also sub in podman.
    31  	// Otherwise, leave the command unchanged.
    32  	if cmd == "podman" || filepath.Base(cmd) == "docker" {
    33  		newCommand = "/proc/self/exe"
    34  	} else {
    35  		newCommand = cmd
    36  	}
    37  
    38  	// If cmd is an absolute or relative path, check if the file exists.
    39  	// Throw an error if it doesn't exist.
    40  	if strings.Contains(newCommand, "/") || strings.HasPrefix(newCommand, ".") {
    41  		res, err := filepath.Abs(newCommand)
    42  		if err != nil {
    43  			return "", err
    44  		}
    45  		if _, err := os.Stat(res); !os.IsNotExist(err) {
    46  			return res, nil
    47  		} else if err != nil {
    48  			return "", err
    49  		}
    50  	}
    51  
    52  	return newCommand, nil
    53  }
    54  
    55  // GenerateCommand takes a label (string) and converts it to an executable command
    56  func GenerateCommand(command, imageName, name, globalOpts string) ([]string, error) {
    57  	var (
    58  		newCommand []string
    59  	)
    60  	if name == "" {
    61  		name = imageName
    62  	}
    63  
    64  	cmd, err := shlex.Split(command)
    65  	if err != nil {
    66  		return nil, err
    67  	}
    68  
    69  	prog, err := substituteCommand(cmd[0])
    70  	if err != nil {
    71  		return nil, err
    72  	}
    73  	newCommand = append(newCommand, prog)
    74  
    75  	for _, arg := range cmd[1:] {
    76  		var newArg string
    77  		switch arg {
    78  		case "IMAGE":
    79  			newArg = imageName
    80  		case "$IMAGE":
    81  			newArg = imageName
    82  		case "IMAGE=IMAGE":
    83  			newArg = fmt.Sprintf("IMAGE=%s", imageName)
    84  		case "IMAGE=$IMAGE":
    85  			newArg = fmt.Sprintf("IMAGE=%s", imageName)
    86  		case "NAME":
    87  			newArg = name
    88  		case "NAME=NAME":
    89  			newArg = fmt.Sprintf("NAME=%s", name)
    90  		case "NAME=$NAME":
    91  			newArg = fmt.Sprintf("NAME=%s", name)
    92  		case "$NAME":
    93  			newArg = name
    94  		case "$GLOBAL_OPTS":
    95  			newArg = globalOpts
    96  		default:
    97  			newArg = arg
    98  		}
    99  		newCommand = append(newCommand, newArg)
   100  	}
   101  	return newCommand, nil
   102  }
   103  
   104  // GenerateRunEnvironment merges the current environment variables with optional
   105  // environment variables provided by the user
   106  func GenerateRunEnvironment(name, imageName string, opts map[string]string) []string {
   107  	newEnv := os.Environ()
   108  	newEnv = append(newEnv, fmt.Sprintf("NAME=%s", name))
   109  	newEnv = append(newEnv, fmt.Sprintf("IMAGE=%s", imageName))
   110  
   111  	if opts["opt1"] != "" {
   112  		newEnv = append(newEnv, fmt.Sprintf("OPT1=%s", opts["opt1"]))
   113  	}
   114  	if opts["opt2"] != "" {
   115  		newEnv = append(newEnv, fmt.Sprintf("OPT2=%s", opts["opt2"]))
   116  	}
   117  	if opts["opt3"] != "" {
   118  		newEnv = append(newEnv, fmt.Sprintf("OPT3=%s", opts["opt3"]))
   119  	}
   120  	return newEnv
   121  }