github.com/google/cadvisor@v0.49.1/container/containerd/identifiers/validate.go (about)

     1  // Copyright 2017 Google Inc. All Rights Reserved.
     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     Copyright The containerd Authors.
    16  
    17     Licensed under the Apache License, Version 2.0 (the "License");
    18     you may not use this file except in compliance with the License.
    19     You may obtain a copy of the License at
    20  
    21         http://www.apache.org/licenses/LICENSE-2.0
    22  
    23     Unless required by applicable law or agreed to in writing, software
    24     distributed under the License is distributed on an "AS IS" BASIS,
    25     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    26     See the License for the specific language governing permissions and
    27     limitations under the License.
    28  */
    29  
    30  // Package identifiers provides common validation for identifiers and keys
    31  // across containerd.
    32  //
    33  // Identifiers in containerd must be a alphanumeric, allowing limited
    34  // underscores, dashes and dots.
    35  //
    36  // While the character set may be expanded in the future, identifiers
    37  // are guaranteed to be safely used as filesystem path components.
    38  package identifiers
    39  
    40  import (
    41  	"regexp"
    42  
    43  	"github.com/google/cadvisor/container/containerd/errdefs"
    44  	"github.com/pkg/errors"
    45  )
    46  
    47  const (
    48  	maxLength  = 76
    49  	alphanum   = `[A-Za-z0-9]+`
    50  	separators = `[._-]`
    51  )
    52  
    53  var (
    54  	// identifierRe defines the pattern for valid identifiers.
    55  	identifierRe = regexp.MustCompile(reAnchor(alphanum + reGroup(separators+reGroup(alphanum)) + "*"))
    56  )
    57  
    58  // Validate returns nil if the string s is a valid identifier.
    59  //
    60  // identifiers are similar to the domain name rules according to RFC 1035, section 2.3.1. However
    61  // rules in this package are relaxed to allow numerals to follow period (".") and mixed case is
    62  // allowed.
    63  //
    64  // In general identifiers that pass this validation should be safe for use as filesystem path components.
    65  func Validate(s string) error {
    66  	if len(s) == 0 {
    67  		return errors.Wrapf(errdefs.ErrInvalidArgument, "identifier must not be empty")
    68  	}
    69  
    70  	if len(s) > maxLength {
    71  		return errors.Wrapf(errdefs.ErrInvalidArgument, "identifier %q greater than maximum length (%d characters)", s, maxLength)
    72  	}
    73  
    74  	if !identifierRe.MatchString(s) {
    75  		return errors.Wrapf(errdefs.ErrInvalidArgument, "identifier %q must match %v", s, identifierRe)
    76  	}
    77  	return nil
    78  }
    79  
    80  func reGroup(s string) string {
    81  	return `(?:` + s + `)`
    82  }
    83  
    84  func reAnchor(s string) string {
    85  	return `^` + s + `$`
    86  }