github.com/hugh712/snapd@v0.0.0-20200910133618-1a99902bd583/osutil/overlay_linux_test.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2016-2018 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package osutil_test
    21  
    22  import (
    23  	. "gopkg.in/check.v1"
    24  
    25  	"github.com/snapcore/snapd/osutil"
    26  )
    27  
    28  type overlaySuite struct{}
    29  
    30  var _ = Suite(&overlaySuite{})
    31  
    32  func (s *overlaySuite) TestIsRootWritableOverlay(c *C) {
    33  	cases := []struct {
    34  		mountinfo    string
    35  		overlay      string
    36  		errorPattern string
    37  	}{{
    38  		// Errors from parsing mountinfo are propagated.
    39  		mountinfo:    "bad syntax",
    40  		errorPattern: "cannot parse mountinfo:.*, .*",
    41  	}, {
    42  		// overlay mounted on / are recognized
    43  		// casper mount source /cow
    44  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay /cow rw,lowerdir=//filesystem.squashfs,upperdir=/cow/upper,workdir=/cow/work",
    45  		overlay:   "/upper",
    46  	}, {
    47  		// casper mount source upperdir trailing slash
    48  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay /cow rw,lowerdir=//filesystem.squashfs,upperdir=/cow/upper/,workdir=/cow/work",
    49  		overlay:   "/upper",
    50  	}, {
    51  		// casper mount source trailing slash
    52  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay /cow/ rw,lowerdir=//filesystem.squashfs,upperdir=/cow/upper,workdir=/cow/work",
    53  		overlay:   "/upper",
    54  	}, {
    55  		// non-casper mount source
    56  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay overlay rw,lowerdir=//filesystem.squashfs,upperdir=/cow/upper,workdir=/cow/work",
    57  		overlay:   "/cow/upper",
    58  	}, {
    59  		// overlay mounted elsewhere are ignored
    60  		mountinfo: "31 1 0:26 /elsewhere /elsewhere rw,relatime shared:1 - overlay /cow rw,lowerdir=//filesystem.squashfs,upperdir=/cow/upper,workdir=/cow/work",
    61  	}, {
    62  		mountinfo: "31 1 0:26 /elsewhere /elsewhere rw,relatime shared:1 - overlay overlay rw,lowerdir=//filesystem.squashfs,upperdir=/cow/upper,workdir=/cow/work",
    63  	}, {
    64  		// casper overlay which results in empty upperdir are ignored
    65  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay /upper rw,lowerdir=//filesystem.squashfs,upperdir=/upper,workdir=/cow/work",
    66  	}, {
    67  		// overlay with relative paths, AARE or double quotes are
    68  		// ignored
    69  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay /cow rw,lowerdir=//filesystem.squashfs,upperdir=cow/upper,workdir=/cow/work",
    70  	}, {
    71  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay /cow rw,lowerdir=//filesystem.squashfs,upperdir=/cow/bad?upper,workdir=/cow/work",
    72  	}, {
    73  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay /cow rw,lowerdir=//filesystem.squashfs,upperdir=/cow/bad*upper,workdir=/cow/work",
    74  	}, {
    75  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay /cow rw,lowerdir=//filesystem.squashfs,upperdir=/cow/bad[upper,workdir=/cow/work",
    76  	}, {
    77  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay overlay rw,lowerdir=//filesystem.squashfs,upperdir=/cow/bad]upper,workdir=/cow/work",
    78  	}, {
    79  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay overlay rw,lowerdir=//filesystem.squashfs,upperdir=/cow/bad{upper,workdir=/cow/work",
    80  	}, {
    81  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay overlay rw,lowerdir=//filesystem.squashfs,upperdir=/cow/bad}upper,workdir=/cow/work",
    82  	}, {
    83  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay overlay rw,lowerdir=//filesystem.squashfs,upperdir=/cow/bad^upper,workdir=/cow/work",
    84  	}, {
    85  		mountinfo: "31 1 0:26 / / rw,relatime shared:1 - overlay overlay rw,lowerdir=//filesystem.squashfs,upperdir=/cow/bad\"upper,workdir=/cow/work",
    86  	}, {
    87  		// The special cased version for 18.10 server release
    88  		mountinfo: "28 0 0:24 / / rw,realtime shared:1 - overlay overlayroot rw,lowerdir=/media/root-ro,upperdir=/media/root-rw/overlay,workdir=/media/root-rw/overlay-workdir/_",
    89  		overlay:   "/overlay",
    90  	}, {
    91  		// The special cased version for Manjaro live CD,
    92  		mountinfo: "37 1 0:24 / / rw,realtime shared:1 - overlay overlay rw,lowerdir=/run/miso/sfs/livefs:/run/miso/sfs/mhwdfs:/run/miso/sfs/desktopfs:/run/miso/sfs/rootfs,upperdir=/run/miso/overlay_root/upper,workdir=/run/miso/overlay_root/work,index=off",
    93  		overlay:   "/upper",
    94  	}}
    95  	for _, tc := range cases {
    96  		restore := osutil.MockMountInfo(tc.mountinfo)
    97  		defer restore()
    98  
    99  		overlay, err := osutil.IsRootWritableOverlay()
   100  		if tc.errorPattern != "" {
   101  			c.Assert(err, ErrorMatches, tc.errorPattern, Commentf("test case %#v", tc))
   102  		} else {
   103  			c.Assert(err, IsNil)
   104  		}
   105  		c.Assert(overlay, Equals, tc.overlay)
   106  	}
   107  }