github.com/kubiko/snapd@v0.0.0-20201013125620-d4f3094d9ddf/client/icons.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2016 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 client
    21  
    22  import (
    23  	"context"
    24  	"fmt"
    25  	"io/ioutil"
    26  	"regexp"
    27  
    28  	"golang.org/x/xerrors"
    29  )
    30  
    31  // Icon represents the icon of an installed snap
    32  type Icon struct {
    33  	Filename string
    34  	Content  []byte
    35  }
    36  
    37  var contentDispositionMatcher = regexp.MustCompile(`attachment; filename=(.+)`).FindStringSubmatch
    38  
    39  // Icon returns the Icon belonging to an installed snap
    40  func (c *Client) Icon(pkgID string) (*Icon, error) {
    41  	const errPrefix = "cannot retrieve icon"
    42  
    43  	response, cancel, err := c.rawWithTimeout(context.Background(), "GET", fmt.Sprintf("/v2/icons/%s/icon", pkgID), nil, nil, nil, nil)
    44  	if err != nil {
    45  		fmt := "%s: failed to communicate with server: %w"
    46  		return nil, xerrors.Errorf(fmt, errPrefix, err)
    47  	}
    48  	defer cancel()
    49  	defer response.Body.Close()
    50  
    51  	if response.StatusCode != 200 {
    52  		return nil, fmt.Errorf("%s: Not Found", errPrefix)
    53  	}
    54  
    55  	matches := contentDispositionMatcher(response.Header.Get("Content-Disposition"))
    56  
    57  	if matches == nil || matches[1] == "" {
    58  		return nil, fmt.Errorf("%s: cannot determine filename", errPrefix)
    59  	}
    60  
    61  	content, err := ioutil.ReadAll(response.Body)
    62  	if err != nil {
    63  		return nil, fmt.Errorf("%s: %s", errPrefix, err)
    64  	}
    65  
    66  	icon := &Icon{
    67  		Filename: matches[1],
    68  		Content:  content,
    69  	}
    70  
    71  	return icon, nil
    72  }