github.com/rigado/snapd@v2.42.5-go-mod+incompatible/cmd/snap/cmd_known.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 main
    21  
    22  import (
    23  	"fmt"
    24  	"strings"
    25  
    26  	"github.com/snapcore/snapd/asserts"
    27  	"github.com/snapcore/snapd/i18n"
    28  	"github.com/snapcore/snapd/overlord/auth"
    29  	"github.com/snapcore/snapd/store"
    30  
    31  	"github.com/jessevdk/go-flags"
    32  )
    33  
    34  type cmdKnown struct {
    35  	clientMixin
    36  	KnownOptions struct {
    37  		// XXX: how to get a list of assert types for completion?
    38  		AssertTypeName assertTypeName `required:"true"`
    39  		HeaderFilters  []string       `required:"0"`
    40  	} `positional-args:"true" required:"true"`
    41  
    42  	Remote bool `long:"remote"`
    43  }
    44  
    45  var shortKnownHelp = i18n.G("Show known assertions of the provided type")
    46  var longKnownHelp = i18n.G(`
    47  The known command shows known assertions of the provided type.
    48  If header=value pairs are provided after the assertion type, the assertions
    49  shown must also have the specified headers matching the provided values.
    50  `)
    51  
    52  func init() {
    53  	addCommand("known", shortKnownHelp, longKnownHelp, func() flags.Commander {
    54  		return &cmdKnown{}
    55  	}, nil, []argDesc{
    56  		{
    57  			// TRANSLATORS: This needs to begin with < and end with >
    58  			name: i18n.G("<assertion type>"),
    59  			// TRANSLATORS: This should not start with a lowercase letter.
    60  			desc: i18n.G("Assertion type name"),
    61  		}, {
    62  			// TRANSLATORS: This needs to begin with < and end with >
    63  			name: i18n.G("<header filter>"),
    64  			// TRANSLATORS: This should not start with a lowercase letter.
    65  			desc: i18n.G("Constrain listing to those matching header=value"),
    66  		},
    67  	})
    68  }
    69  
    70  var storeNew = store.New
    71  
    72  func downloadAssertion(typeName string, headers map[string]string) ([]asserts.Assertion, error) {
    73  	var user *auth.UserState
    74  
    75  	// FIXME: set auth context
    76  	var storeCtx store.DeviceAndAuthContext
    77  
    78  	at := asserts.Type(typeName)
    79  	if at == nil {
    80  		return nil, fmt.Errorf("cannot find assertion type %q", typeName)
    81  	}
    82  	primaryKeys, err := asserts.PrimaryKeyFromHeaders(at, headers)
    83  	if err != nil {
    84  		return nil, fmt.Errorf("cannot query remote assertion: %v", err)
    85  	}
    86  
    87  	sto := storeNew(nil, storeCtx)
    88  	as, err := sto.Assertion(at, primaryKeys, user)
    89  	if err != nil {
    90  		return nil, err
    91  	}
    92  
    93  	return []asserts.Assertion{as}, nil
    94  }
    95  
    96  func (x *cmdKnown) Execute(args []string) error {
    97  	if len(args) > 0 {
    98  		return ErrExtraArgs
    99  	}
   100  
   101  	// TODO: share this kind of parsing once it's clearer how often is used in snap
   102  	headers := map[string]string{}
   103  	for _, headerFilter := range x.KnownOptions.HeaderFilters {
   104  		parts := strings.SplitN(headerFilter, "=", 2)
   105  		if len(parts) != 2 {
   106  			return fmt.Errorf(i18n.G("invalid header filter: %q (want key=value)"), headerFilter)
   107  		}
   108  		headers[parts[0]] = parts[1]
   109  	}
   110  
   111  	var assertions []asserts.Assertion
   112  	var err error
   113  	if x.Remote {
   114  		assertions, err = downloadAssertion(string(x.KnownOptions.AssertTypeName), headers)
   115  	} else {
   116  		assertions, err = x.client.Known(string(x.KnownOptions.AssertTypeName), headers)
   117  	}
   118  	if err != nil {
   119  		return err
   120  	}
   121  
   122  	enc := asserts.NewEncoder(Stdout)
   123  	for _, a := range assertions {
   124  		enc.Encode(a)
   125  	}
   126  
   127  	return nil
   128  }