on_roles(roles, hosts:, parallel: true, &block) — SSHKitDslRoles

on_roles(roles, hosts:, parallel: true, &block)

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

Parameters

roles req
hosts keyreq
parallel key = true
block block

Source

# 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

Defined in lib/kamal/sshkit_with_ext.rb line 230 · View on GitHub · Improve this page · Find usages on GitHub

Defined in SSHKitDslRoles

Signature

Parameters