Pharos init command for cluster.yml bootstrapping

lib/pharos/init_command.rb

@@ -0,0 +1,154 @@
+# frozen_string_literal: true
+
+module Pharos
+  class InitCommand < Pharos::Command
+    using Pharos::CoreExt::DeepTransformKeys
+
+    banner 'Create a Pharos cluster configuration'
+
+    option %w(-c --config), 'FILE', 'output filename', default: 'cluster.yml', attribute_name: :config_file
+    option '--defaults', :flag, 'include all configuration default values'
+
+    option %w(-m --master), 'HOST', 'master host [user@]address[:port] (can be given multiple times)' do |master|
+      @hosts ||= []
+      @hosts << parse_host(master).merge(role: 'master')
+    end
+
+    option %w(-w --worker), 'HOST', 'worker host [user@]address[:port] (can be given multiple times)' do |worker|
+      @hosts ||= []
+      @hosts << parse_host(worker).merge(role: 'worker')
+    end
+
+    option %w(-b --bastion), 'HOST', 'bastion (ssh proxy) host [user@]address[:port]' do |bastion|
+      parse_host(bastion)
+    end
+
+    option %w(-n --name), 'NAME', 'cluster name'
+
+    option %w(-e --env), 'KEY=VALUE', 'host environment variables (can be given multiple times)', multivalued: true do |kv_pair|
+      Hash[*kv_pair.split('=', 2)]
+    end
+
+    option %w(-i --ssh-key-path), 'PATH', 'ssh key path'
+
+    def parse_host(host_str)
+      user = host_str[/(.+?)@/, 1]
+      address = host_str[/(?:.+?@)?([^:]+)/, 1]
+      ssh_port = host_str[/:(\d+)/, 1]&.to_i
+      { address: address, user: user, ssh_port: ssh_port }
+    end
+
+    PRESET_CFG = <<~CONFIG_TPL
+      # For full configuration reference, see https://pharos.sh/docs/configuration/
+      ---
+      name: <%= name  %>
+
+      host_defaults: &host_defaults
+        user: <%= host_defaults[:user] %>
+        <%- if host_defaults[:ssh_key_path] -%>
+        ssh_key_path: <%= host_defaults[:ssh_key_path] %>
+        <%- else -%>
+        # ssh_key_path: ~/.ssh/id_rsa
+        <%- end -%>
+        ssh_port: 22
+        <%- if host_defaults[:environment] -%>
+        environment:
+          <%- host_defaults[:environment].each do |key, value| -%>
+          <%= key %>: <%= value.inspect %>
+          <%- end -%>
+        <%- else -%>
+        # environment:
+        #   HTTP_PROXY: 192.168.0.1
+        <%- end -%>
+        <%- if host_defaults[:bastion] -%>
+        bastion:
+          address: <%= host_defaults[:bastion][:address] %>
+          <%- if host_defaults[:bastion][:user] -%>
+          user: <%= host_defaults[:bastion][:user] %>
+          <%- end -%>
+          <%- if host_defaults[:bastion][:ssh_port] -%>
+          ssh_port: <%= host_defaults[:bastion][:ssh_port] %>
+          <%- end -%>
+          <%- if host_defaults[:ssh_key_path] -%>
+          ssh_key_path: <%= host_defaults[:ssh_key_path] %>
+          <%- else -%>
+          # ssh_key_path: ~/.ssh/id_rsa
+          <%- end -%>
+        <%- else -%>
+        # bastion:
+        #   address: 192.168.0.1
+        #   user: bastion
+        #   ssh_key_path: ~/.ssh/id_rsa
+        <%- end -%>
+
+      hosts:
+        <%- hosts.each do |host| -%>
+        - <<: *host_defaults
+          address: <%= host[:address] %>
+          <%- if host[:user] && host[:user] != host_defaults[:user] -%>
+          user: <%= host[:user] %>
+          <%- end -%>
+          <%- if host[:private_address] -%>
+          private_address: <%= host[:private_address] %>
+          <%- else -%>
+          # private_address: 10.0.0.1
+          <%- end -%>
+          <%- if host[:ssh_port] != host_defaults[:ssh_port] -%>
+          ssh_port: <%= host[:ssh_port] %>
+          <%- end -%>
+          role: <%= host[:role] %>
+        <%- end -%>
+
+      network:
+        provider: weave
+
+      addons:
+        ingress-nginx:
+          enabled: true
+    CONFIG_TPL
+
+    def default_name
+      Pharos::Phases::ConfigureClusterName.new('').random_name
+    end
+
+    def host_defaults
+      {}.tap do |defaults|
+        defaults[:bastion] = bastion if bastion
+        defaults[:user] = hosts.find { |h| h[:user] }&.fetch(:user) || ENV['USER'] || 'username'
+        defaults[:environment] = env_list.inject(:merge) unless env_list.empty?
+        defaults[:ssh_key_path] = ssh_key_path if ssh_key_path
+      end
+    end
+
+    def hosts
+      @hosts ||= [
+        # dummy example hosts
+        { address: '10.0.0.1', private_address: '172.16.0.1', role: 'master', ssh_key_path: '~/.ssh/id_rsa' },
+        { address: '10.0.0.2', private_address: '172.16.0.2', role: 'worker', ssh_key_path: '~/.ssh/id_rsa' }
+      ]
+    end
+
+    def config_content
+      require 'pharos/phases/configure_cluster_name'
+
+      if defaults?
+        hosts.each { |h| h.replace(host_defaults.merge(h)) }
+        {
+          name: name,
+          hosts: hosts.map { |h| h.merge(host_defaults) }
+        }.merge(Pharos::Config.new.to_h).deep_stringify_keys.to_yaml
+      else
+        Pharos::YamlFile.new(StringIO.new(PRESET_CFG)).erb_result(
+          hosts: hosts,
+          host_defaults: host_defaults,
+          name: name
+        )
+      end
+    end
+
+    def execute
+      signal_error "configuration file #{config_file} already exists" if File.exist?(config_file)
+      File.write(config_file, config_content)
+    end
+  end
+end

lib/pharos/phases/configure_cluster_name.rb

@@ -71,10 +71,14 @@ def generate_new_name
         return false if @config.name
         return nil if cluster_context['no-generate-name']
 
-        new_name = "#{ADJECTIVES.sample}-#{NOUNS.sample}-#{'%04d' % rand(9999)}"
+        new_name = random_name
         logger.info "Using generated random name #{new_name.magenta} as cluster name"
         new_name
       end
+
+      def random_name
+        "#{ADJECTIVES.sample}-#{NOUNS.sample}-#{'%04d' % rand(9999)}"
+      end
     end
   end
 end

lib/pharos/root_command.rb

@@ -6,6 +6,7 @@
 require_relative 'kubeconfig_command'
 require_relative 'exec_command'
 require_relative 'terraform_command'
+require_relative 'init_command'
 
 module Pharos
   class RootCommand < Pharos::Command
@@ -16,6 +17,7 @@ class RootCommand < Pharos::Command
     subcommand "reset", "reset cluster", ResetCommand
     subcommand %w(exec ssh), "run a command or an interactive session on a host", ExecCommand
     subcommand %w(tf terraform), "terraform specific commands", TerraformCommand
+    subcommand "init", "create an initial cluster configuration file", InitCommand
     subcommand "version", "show version information", VersionCommand
   end
 end