Module: QB::Util::DockerMixin::ClassMethods

Defined in:
lib/qb/util/docker_mixin.rb

Overview

Class methods to extend the receiver with when QB::Util::DockerMixin is included.

Instance Method Summary collapse

Instance Method Details

#check_docker_tag(string) ⇒ nil

Check that string is a valid Docker image tag, raising an error if not.

Check is performed via #valid_docker_tag.

Parameters:

  • string —

    see QB::Util::DockerMixin::ClassMethods#valid_docker_tag

Returns:

  • (nil) 


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# File 'lib/qb/util/docker_mixin.rb', line 41

def check_docker_tag string
  unless valid_docker_tag? string
    raise ArgumentError.new NRSER.squish <<-END
      Argument #{ string.inspect } is not a valid Docker image tag.
    END
  end
  nil
end

#to_docker_tag(semver) ⇒ String

Convert a Semver version string to a string suitable for use as a Docker image tag, which, as of writing, are restricted to

[A-Za-z0-9_.-]

and 128 characters max (used to be 30, but seems it's been increased).

This restriction prohibits Semver strings that use + to separate the build segments.

We replace + with _.

_ is not a legal character in Semver or Ruby Gem versions, making it clear that the resulting string is for Docker use, and allowing parsing to get back to an equal Package::Version instance.

Parameters:

  • semver (String) —

    A legal [Semver][] version string to convert.

Returns:

  • (String) —

    Legal Docker image tag corresponding to semver.

Raises:

  • (ArgumentError) —

    If the resulting string is longer than DOCKER_TAG_MAX_CHARACTERS.

  • (ArgumentError) —

    If the resulting string still contains invalid characters for a Docker image tag after the substitution.



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# File 'lib/qb/util/docker_mixin.rb', line 87

def to_docker_tag semver
  semver.gsub('+', '_').tap { |docker_tag|
    check_docker_tag docker_tag
  }
end

#valid_docker_tag?(string) ⇒ Boolean

Test if string is a valid Docker image tag by seeing if it matches DOCKER_TAG_VALID_RE

Parameters:

  • string (String) —

    String to test.

Returns:

  • (Boolean) —

    True if string is a valid Docker image tag.



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# File 'lib/qb/util/docker_mixin.rb', line 28

def valid_docker_tag? string
  DockerMixin::DOCKER_TAG_VALID_RE =~ string
end