plash nodepath

Usage

plash nodepath CONTAINER [--allow-root-container]

Description

Prints the path of a given image.

The --allow-root-container option
allows the root image ("0") to be specified as image.

Example

$ plash nodepath 19
home/ihucos/.plashdata/layer/0/2/19
$ plash nodepath 19 | xargs tree

Tested Behaviour

#!/bin/bash

set -exu

(! plash nodepath mynoexistentimage)

newcont=$(plash build -f 1 --invalidate-layer)

nodepath=$(plash nodepath $newcont)

echo $nodepath | grep $newcont

layerup=$(plash build -f $newcont --layer --invalidate-layer)

nodepath=$(plash nodepath $layerup)

echo $nodepath | grep $newcont

echo $nodepath | grep $layerup

• test positive number validation

[[ "$(plash nodepath xx   2>&1)" = *"positive number"* ]]

[[ "$(plash nodepath 222x 2>&1)" = *"positive number"* ]]

[[ "$(plash nodepath x222 2>&1)" = *"positive number"* ]]

[[ "$(plash nodepath -1   2>&1)" = *"positive number"* ]]

[[ "$(plash nodepath --   2>&1)" = *"positive number"* ]]

[[ "$(plash nodepath ""   2>&1)" = *"positive number"* ]]

• test querying for the special root image

[[ "$(plash nodepath 0 2>&1)" = *"special root image"* ]]

[[ "$(plash nodepath 0 --allow-root-container 2>&1)" = *"/layer/0" ]]

plash nodepath 0 --allow-root-container

• check bad PLASH_DATA error

[[ "$(PLASH_DATA=/xxx plash nodepath 1 2>&1)" = *"/xxx: No such file or directory" ]]

• no argument gets help message

[[ "$(plash nodepath 2>&1)" = *"usage: "* ]]

Source Code

#define USAGE "usage: plash nodepath CONTAINER [--allow-root-container]\n"

#define _GNU_SOURCE
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <inttypes.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>

#include <plash.h>

int nodepath_main(int argc, char *argv[]) {

  int i = 0;
  char *nodepath, *plash_data;

  if (argc < 2) {
    fputs(USAGE, stderr);
    return EXIT_FAILURE;
  }

  // validate/normalize input
  if (!argv[1][0] || strspn(argv[1], "0123456789") != strlen(argv[1]))
    pl_fatal("image arg must be a positive number, got: %s", argv[1]);

  if (0 == strcmp(argv[1], "0") &&
      (argc <= 2 || 0 != strcmp(argv[2], "--allow-root-container"))) {
    pl_fatal("image must not be the special root image ('0')");
  }

  plash_data = pl_call("data");
  if (chdir(plash_data) == -1 || chdir("index") == -1)
    pl_fatal("run `plash init`: chdir: %s", plash_data);

  if (!(nodepath = realpath(argv[1], NULL))) {
    errno = 0;
    pl_fatal("no image: %s", argv[1]);
  }
  puts(nodepath);
  return EXIT_SUCCESS;
}