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, vendor_index, working_dir, backend) ⇒ Object 



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# File 'lib/inspec/dependencies/resolver.rb', line 26

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

Instance Method Details

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



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# File 'lib/inspec/dependencies/resolver.rb', line 34

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

  deps.each do |dep|
    path_string = if path_string.empty?
                    dep.name
                  else
                    path_string + " -> #{dep.name}"
                  end

    if seen_items.key?(dep.source_url)
      fail Inspec::CyclicDependencyError, "Dependency #{dep} would cause a dependency cycle (#{path_string})"
    else
      seen_items[dep.source_url] = true
    end

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

    Inspec::Log.debug("Adding #{dep.source_url}")
    graph[dep.name] = dep
    if !dep.dependencies.empty?
      # Recursively resolve any transitive dependencies.
      resolve(dep.dependencies, false, seen_items.dup, path_string)
    end
  end

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