Module: SSHKitDslRoles

Defined in:
lib/kamal/sshkit_with_ext.rb

Instance Method Summary collapse

Instance Method Details

#on_roles(roles, hosts:, parallel: true, &block) ⇒ Object

Execute on hosts grouped by role.

Unlike ‘on()` which deduplicates hosts, this allows the same host to have multiple concurrent connections when it appears in multiple roles.

Options:

hosts: The hosts to run on (required)
parallel: When true, each role runs in its own thread with separate
          connections. When false, hosts run in parallel but roles on each
          host run sequentially (default: true)

Example:

on_roles(roles) do |host, role|
  # deploy role to host
end



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# File 'lib/kamal/sshkit_with_ext.rb', line 230

def on_roles(roles, hosts:, parallel: true, &block)
  if parallel
    threads = roles.filter_map do |role|
      if (role_hosts = role.hosts & hosts).any?
        Thread.new do
          on(role_hosts) { |host| instance_exec(host, role, &block) }
        rescue StandardError => e
          raise SSHKit::Runner::ExecuteError.new(e), "Exception while executing on #{role}: #{e.message}"
        end
      end
    end

    exceptions = []
    threads.each do |t|
      begin
        t.join
      rescue SSHKit::Runner::ExecuteError => e
        exceptions << e
      end
    end

    if exceptions.one?
      raise exceptions.first
    elsif exceptions.many?
      raise exceptions.first, [ "Exceptions on #{exceptions.count} roles:", exceptions.map(&:message) ].join("\n")
    end
  else
    # Host-first iteration: hosts run in parallel, roles on each host run sequentially
    on(hosts) do |host|
      roles.each do |role|
        instance_exec(host, role, &block) if role.hosts.include?(host.to_s)
      end
    end
  end
end