Class: Inspec::Resolver

Inherits:
Object
  • Object
show all
Defined in:
lib/inspec/dependencies/resolver.rb

Overview

Inspec::Resolver is a simple dependency resolver. Unlike Bundler or Berkshelf, it does not attempt to resolve each named dependency to a single version. Rather, it traverses down the dependency tree and:

  • Fetches the dependency from the source

  • Checks the presence of cycles, and

  • Checks that the specified dependency source satisfies the specified version constraint

The full dependency tree is then available for the loader, which will provide the isolation necessary to support multiple versions of the same profile being used at runtime.

Currently the fetching happens somewhat lazily depending on the implementation of the fetcher being used.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.resolve(dependencies, cache, working_dir, backend) ⇒ Object

Here deps is an Array of Hashes



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# File 'lib/inspec/dependencies/resolver.rb', line 27

def self.resolve(dependencies, cache, working_dir, backend)
  reqs = dependencies.map do |dep|
    req = Inspec::Requirement.from_metadata(dep, cache, cwd: working_dir, backend: backend)
    req || raise("Cannot initialize dependency: #{req}")
  end
  new.resolve(reqs)
end

Instance Method Details

#detect_duplicates(deps, top_level, path_string) ⇒ Object 



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# File 'lib/inspec/dependencies/resolver.rb', line 35

def detect_duplicates(deps, top_level, path_string)
  seen_items_local = []
  deps.each do |dep|
    if seen_items_local.include?(dep.name)
      problem_cookbook = if top_level
                           'the inspec.yml for this profile.'
                         else
                           "the dependency information for #{path_string.split(' ').last}"
                         end
      raise Inspec::DuplicateDep, "The dependency #{dep.name} is listed twice in #{problem_cookbook}"
    else
      seen_items_local << dep.name
    end
  end
end

#resolve(deps, top_level = true, seen_items = {}, path_string = '') ⇒ Object

Here deps is an Array of Inspec::Requirement



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# File 'lib/inspec/dependencies/resolver.rb', line 52

def resolve(deps, top_level = true, seen_items = {}, path_string = '') # rubocop:disable Metrics/AbcSize
  graph = {}
  if top_level
    Inspec::Log.debug("Starting traversal of dependencies #{deps.map(&:to_s)}")
  else
    Inspec::Log.debug("Traversing dependency tree of transitive dependency #{deps.map(&:name)}")
  end

  detect_duplicates(deps, top_level, path_string)
  deps.each do |dep|
    new_seen_items = seen_items.dup
    new_path_string = if path_string.empty?
                        dep.name
                      else
                        path_string + " -> #{dep.name}"
                      end

    raise Inspec::CyclicDependencyError, "Dependency #{dep} would cause a dependency cycle (#{new_path_string})" if new_seen_items.key?(dep.resolved_source)

    new_seen_items[dep.resolved_source] = true

    if !dep.source_satisfies_spec?
      raise Inspec::UnsatisfiedVersionSpecification, "The profile #{dep.name} from #{dep.resolved_source} has a version #{dep.source_version} which doesn't match #{dep.version_constraints}"
    end

    Inspec::Log.debug("Adding dependency #{dep.name} (#{dep.resolved_source})")
    graph[dep.name] = dep
    if !dep.dependencies.empty?
      resolve(dep.dependencies, false, new_seen_items.dup, new_path_string)
    end
  end

  Inspec::Log.debug('Dependency traversal complete.') if top_level
  graph
end