rough draft for systemd export support

http://0pointer.de/blog/projects/systemd.html

This adds support for exporting systemd targets and services.  The
structure is based on the existing upstart support.

Quality is draft and expected to refine in the coming weeks.

One Foremanism that is not respected by these export templates is the
usual log output location, instead stdout and stderr go to syslog.

data/export/systemd/master.target.erb

@@ -0,0 +1 @@
+[Unit]

data/export/systemd/process.service.erb

@@ -0,0 +1,17 @@
+[Unit]
+StopWhenUnneeded=true
+
+[Service]
+User=<%= user %>
+WorkingDirectory=<%= engine.root %>
+Environment=PORT=<%= port %><% engine.env.each_pair do |var,env| %>
+Environment=<%= var.upcase %>=<%= env %><% end %>
+ExecStart=/bin/bash -lc '<%= process.command %>'
+Restart=always
+StandardInput=null
+StandardOutput=syslog
+StandardError=syslog
+SyslogIdentifier=%n
+
+[Install]
+WantedBy=<%= app %>-<%= name %>.target

data/export/systemd/process_master.target.erb

@@ -0,0 +1,5 @@
+[Unit]
+StopWhenUnneeded=true
+
+[Install]
+WantedBy=<%= app %>.target

lib/foreman/export.rb

@@ -32,3 +32,4 @@ require "foreman/export/bluepill"
 require "foreman/export/runit"
 require "foreman/export/supervisord"
 require "foreman/export/launchd"
+require "foreman/export/systemd"

lib/foreman/export/systemd.rb

@@ -0,0 +1,25 @@
+require "erb"
+require "foreman/export"
+
+class Foreman::Export::Systemd < Foreman::Export::Base
+
+  def export
+    super
+
+    Dir["#{location}/#{app}*.target"].concat(Dir["#{location}/#{app}*.service"]).each do |file|
+      clean file
+    end
+
+    write_template "systemd/master.target.erb", "#{app}.target", binding
+
+    engine.each_process do |name, process|
+      next if engine.formation[name] < 1
+      write_template "systemd/process_master.target.erb", "#{app}-#{name}.target", binding
+
+      1.upto(engine.formation[name]) do |num|
+        port = engine.port_for(process, num)
+        write_template "systemd/process.service.erb", "#{app}-#{name}-#{num}.service", binding
+      end
+    end
+  end
+end

man/foreman.1.ronn

@@ -103,6 +103,8 @@ foreman currently supports the following output formats:
 
   * runit
 
+  * systemd
+
   * upstart
 
 ## INITTAB EXPORT
@@ -114,6 +116,17 @@ Will export a chunk of inittab-compatible configuration:
     EX02:4:respawn:/bin/su - example -c 'PORT=5100 bundle exec rake jobs:work >> /var/log/job-1.log 2>&1'
     # ----- end foreman example processes -----
 
+## SYSTEMD EXPORT
+
+Will create a series of systemd scripts in the location you specify. Scripts
+will be structured to make the following commands valid:
+
+  `systemctl start appname.target`
+
+  `systemctl stop appname-processname.target`
+
+  `systemctl restart appname-processname-3.service`
+
 ## UPSTART EXPORT
 
 Will create a series of upstart scripts in the location you specify. Scripts

spec/foreman/export/systemd_spec.rb

@@ -0,0 +1,87 @@
+require "spec_helper"
+require "foreman/engine"
+require "foreman/export/systemd"
+require "tmpdir"
+
+describe Foreman::Export::Systemd, :fakefs do
+  let(:procfile)  { write_procfile("/tmp/app/Procfile") }
+  let(:formation) { nil }
+  let(:engine)    { Foreman::Engine.new(:formation => formation).load_procfile(procfile) }
+  let(:options)   { Hash.new }
+  let(:systemd)   { Foreman::Export::Systemd.new("/tmp/init", engine, options) }
+
+  before(:each) { load_export_templates_into_fakefs("systemd") }
+  before(:each) { stub(systemd).say }
+
+  it "exports to the filesystem" do
+    systemd.export
+
+    File.read("/tmp/init/app.target").should          == example_export_file("systemd/app.target")
+    File.read("/tmp/init/app-alpha.target").should    == example_export_file("systemd/app-alpha.target")
+    File.read("/tmp/init/app-alpha-1.service").should == example_export_file("systemd/app-alpha-1.service")
+    File.read("/tmp/init/app-bravo.target").should    == example_export_file("systemd/app-bravo.target")
+    File.read("/tmp/init/app-bravo-1.service").should == example_export_file("systemd/app-bravo-1.service")
+  end
+
+  it "cleans up if exporting into an existing dir" do
+    mock(FileUtils).rm("/tmp/init/app.target")
+    mock(FileUtils).rm("/tmp/init/app-alpha.target")
+    mock(FileUtils).rm("/tmp/init/app-alpha-1.service")
+    mock(FileUtils).rm("/tmp/init/app-bravo.target")
+    mock(FileUtils).rm("/tmp/init/app-bravo-1.service")
+
+    systemd.export
+    systemd.export
+  end
+
+  it "includes environment variables" do
+    engine.env['KEY'] = 'some "value"'
+    systemd.export
+    File.read("/tmp/init/app-alpha-1.service").should =~ /KEY=some "value"$/
+  end
+
+  context "with a formation" do
+    let(:formation) { "alpha=2" }
+
+    it "exports to the filesystem with concurrency" do
+      systemd.export
+
+      File.read("/tmp/init/app.target").should             == example_export_file("systemd/app.target")
+      File.read("/tmp/init/app-alpha.target").should       == example_export_file("systemd/app-alpha.target")
+      File.read("/tmp/init/app-alpha-1.service").should    == example_export_file("systemd/app-alpha-1.service")
+      File.read("/tmp/init/app-alpha-2.service").should    == example_export_file("systemd/app-alpha-2.service")
+      File.exists?("/tmp/init/app-bravo-1.service").should == false
+    end
+  end
+
+  context "with alternate templates" do
+    let(:template) { "/tmp/alternate" }
+    let(:options)  { { :app => "app", :template => template } }
+
+    before do
+      FileUtils.mkdir_p template
+      File.open("#{template}/master.target.erb", "w") { |f| f.puts "alternate_template" }
+    end
+
+    it "can export with alternate template files" do
+      systemd.export
+      File.read("/tmp/init/app.target").should == "alternate_template\n"
+    end
+  end
+
+  context "with alternate templates from home dir" do
+
+    before do
+      FileUtils.mkdir_p File.expand_path("~/.foreman/templates/systemd")
+      File.open(File.expand_path("~/.foreman/templates/systemd/master.target.erb"), "w") do |file|
+        file.puts "default_alternate_template"
+      end
+    end
+
+    it "can export with alternate template files" do
+      systemd.export
+      File.read("/tmp/init/app.target").should == "default_alternate_template\n"
+    end
+  end
+
+end

spec/resources/export/systemd/app-alpha-1.service

@@ -0,0 +1,16 @@
+[Unit]
+StopWhenUnneeded=true
+
+[Service]
+User=app
+WorkingDirectory=/tmp/app
+Environment=PORT=5000
+ExecStart=/bin/bash -lc './alpha'
+Restart=always
+StandardInput=null
+StandardOutput=syslog
+StandardError=syslog
+SyslogIdentifier=%n
+
+[Install]
+WantedBy=app-alpha.target

spec/resources/export/systemd/app-alpha-2.service

@@ -0,0 +1,16 @@
+[Unit]
+StopWhenUnneeded=true
+
+[Service]
+User=app
+WorkingDirectory=/tmp/app
+Environment=PORT=5001
+ExecStart=/bin/bash -lc './alpha'
+Restart=always
+StandardInput=null
+StandardOutput=syslog
+StandardError=syslog
+SyslogIdentifier=%n
+
+[Install]
+WantedBy=app-alpha.target

spec/resources/export/systemd/app-alpha.target

@@ -0,0 +1,5 @@
+[Unit]
+StopWhenUnneeded=true
+
+[Install]
+WantedBy=app.target

spec/resources/export/systemd/app-bravo-1.service

@@ -0,0 +1,16 @@
+[Unit]
+StopWhenUnneeded=true
+
+[Service]
+User=app
+WorkingDirectory=/tmp/app
+Environment=PORT=5100
+ExecStart=/bin/bash -lc './bravo'
+Restart=always
+StandardInput=null
+StandardOutput=syslog
+StandardError=syslog
+SyslogIdentifier=%n
+
+[Install]
+WantedBy=app-bravo.target

spec/resources/export/systemd/app-bravo.target

@@ -0,0 +1,5 @@
+[Unit]
+StopWhenUnneeded=true
+
+[Install]
+WantedBy=app.target

spec/resources/export/systemd/app.target

@@ -0,0 +1 @@
+[Unit]