go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/auth/integration/gsutil/boto.go (about)

     1  // Copyright 2019 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package gsutil
    16  
    17  import (
    18  	"bytes"
    19  	"os"
    20  	"path/filepath"
    21  
    22  	"go.chromium.org/luci/common/errors"
    23  )
    24  
    25  // Boto represents a subset of .boto gsutil configuration file.
    26  type Boto struct {
    27  	StateDir          string // value of GSUtil.state_dir
    28  	RefreshToken      string // value of Credentials.gs_oauth2_refresh_token
    29  	GCEServiceAccount string // value of GoogleCompute.service_account
    30  	ProviderLabel     string // value of OAuth2.provider_label
    31  	ProviderAuthURI   string // value of OAuth2.provider_authorization_uri
    32  	ProviderTokenURI  string // value of OAuth2.provider_token_uri
    33  }
    34  
    35  // Write creates the config file.
    36  func (b *Boto) Write(path string) error {
    37  	buf := bytes.Buffer{}
    38  
    39  	line := func(s string) {
    40  		buf.WriteString(s)
    41  		buf.WriteRune('\n')
    42  	}
    43  
    44  	opts := func(name, value string) {
    45  		if value != "" {
    46  			buf.WriteString(name)
    47  			buf.WriteString(" = ")
    48  			buf.WriteString(value)
    49  			buf.WriteRune('\n')
    50  		}
    51  	}
    52  
    53  	line("# Autogenerated by LUCI. Do not edit.")
    54  	line("")
    55  	line("[GSUtil]")
    56  	opts("software_update_check_period", "0")
    57  	opts("state_dir", b.StateDir)
    58  	if b.RefreshToken != "" {
    59  		line("")
    60  		line("[Credentials]")
    61  		opts("gs_oauth2_refresh_token", b.RefreshToken)
    62  	}
    63  	if b.GCEServiceAccount != "" {
    64  		line("")
    65  		line("[GoogleCompute]")
    66  		opts("service_account", b.GCEServiceAccount)
    67  	}
    68  	if b.ProviderLabel != "" || b.ProviderAuthURI != "" || b.ProviderTokenURI != "" {
    69  		line("")
    70  		line("[OAuth2]")
    71  		opts("provider_label", b.ProviderLabel)
    72  		opts("provider_authorization_uri", b.ProviderAuthURI)
    73  		opts("provider_token_uri", b.ProviderTokenURI)
    74  	}
    75  
    76  	return os.WriteFile(path, buf.Bytes(), 0600)
    77  }
    78  
    79  // PrepareStateDir prepares a directory (based on b.StateDir) for gsutil to keep
    80  // its state and drops .boto config there.
    81  //
    82  // Returns path to the created .boto file.
    83  func PrepareStateDir(b *Boto) (string, error) {
    84  	if err := os.MkdirAll(b.StateDir, 0700); err != nil {
    85  		return "", errors.Annotate(err, "failed to create gsutil state dir at %s", b.StateDir).Err()
    86  	}
    87  
    88  	botoCfg := filepath.Join(b.StateDir, ".boto")
    89  	if err := b.Write(botoCfg); err != nil {
    90  		return "", errors.Annotate(err, "failed to write %s", botoCfg).Err()
    91  	}
    92  
    93  	// Make sure the credentials cache file is empty, otherwise it will grow
    94  	// after each server launch, since it uses refresh_token (which we may
    95  	// generate randomly) as a cache key. We don't really need this cache anyway.
    96  	if err := os.Remove(filepath.Join(b.StateDir, "credstore")); err != nil && !os.IsNotExist(err) {
    97  		return "", errors.Annotate(err, "failed to remove credstore").Err()
    98  	}
    99  
   100  	return botoCfg, nil
   101  }