vagrant/plugins/providers/docker/command/logs.rb

module VagrantPlugins
  module DockerProvider
    module Command
      class Logs < Vagrant.plugin("2", :command)
        def self.synopsis
          "outputs the logs from the Docker container"
        end

        def execute
          options = {}
          options[:follow] = false
          options[:prefix] = true

          opts = OptionParser.new do |o|
            o.banner = "Usage: vagrant docker-logs [options]"
            o.separator ""
            o.separator "Options:"
            o.separator ""

            o.on("--[no-]follow", "Continue streaming in log output") do |f|
              options[:follow] = f
            end

            o.on("--[no-]prefix", "Don't prefix output with machine names") do |p|
              options[:prefix] = p
            end
          end

          # Parse the options
          argv = parse_options(opts)
          return if !argv

          output_options = {}
          output_options[:prefix] = false if !options[:prefix]

          # TODO: exit with exit status != 0 if all machines are unknown
          # or not created.

          # Go through each machine and execute the client on it
          with_target_vms(argv) do |machine|
            if machine.provider_name != :docker
              machine.ui.output(I18n.t("docker_provider.not_docker_provder"))
              next
            end

            state = machine.state
            if state == :host_state_unknown
              machine.ui.output(I18n.t("docker_provider.logs_host_state_unknown"))
              next
            elsif state == :not_created
              machine.ui.output(I18n.t("docker_provider.not_created_skip"))
              next
            end

            command = ["docker", "logs"]
            command << "--follow" if options[:follow]
            command << machine.id

            data_acc = ""
            machine.provider.driver.execute(*command) do |type, data|
              # Accumulate the data so we only output lines at a time
              data_acc << data

              # If we have a newline, then output all the lines we have so far
              if data_acc.include?("\n")
                lines    = data_acc.split("\n")

                if !data_acc.end_with?("\n")
                  data_acc = lines.pop.chomp
                else
                  data_acc = ""
                end

                lines.each do |line|
                  line = " " if line == ""
                  machine.ui.output(line, **output_options)
                end
              end
            end

            # Output any remaining data
            machine.ui.output(data_acc, **output_options) if !data_acc.empty?
          end
        end
      end
    end
  end
end