Add salt plugin

- uses salt bootstrap to install minion code
 - custom grains can be set.
 - option to specify master in the manifest.

e.g manifest (TODO: Add this to doc.)

"salt": {
            "install_source": "git",
            "version": "develop", \\ Only if the source is git
            "master": "", \\ salt master ip or fqdn
            "grains": {
                "custom_grain1": "custom_grain_value1",
                "custom_grain2": "custom_grain_value2",
            }
        }

bootstrapvz/plugins/salt/__init__.py

@@ -0,0 +1,14 @@
+import tasks
+
+
+def validate_manifest(data, validator, error):
+	import os.path
+	schema_path = os.path.normpath(os.path.join(os.path.dirname(__file__), 'manifest-schema.json'))
+	validator(data, schema_path)
+
+
+def resolve_tasks(taskset, manifest):
+	taskset.add(tasks.InstallSaltDependencies)
+	taskset.add(tasks.BootstrapSaltMinion)
+	if 'grains' in manifest.plugins['salt']:
+		taskset.add(tasks.SetSaltGrains)

bootstrapvz/plugins/salt/manifest-schema.json

@@ -0,0 +1,38 @@
+{
+	"$schema": "http://json-schema.org/draft-04/schema#",
+	"title": "Saltstack plugin manifest",
+	"type": "object",
+	"properties": {
+		"plugins": {
+			"type": "object",
+			"properties": {
+				"salt": {
+					"type": "object",
+					"properties": {
+						"master": {
+							"type": "string"
+						},
+                        "install_source": {
+                            "type": "string"
+                        },
+						"version": {
+							"type": "string"
+						},
+                        "grains": {
+                            "type": "object",
+                            "patternProperties": {
+						        "^[^\/\\0]+$": {
+							        "type": "string"
+						        }
+					        },
+                            "minItems": 1
+                        }
+					},
+					"required": ["install_source"]
+				}
+			},
+			"required": ["salt"]
+		}
+	},
+	"required": ["plugins"]
+}

bootstrapvz/plugins/salt/tasks.py

@@ -0,0 +1,65 @@
+from bootstrapvz.base import Task
+from bootstrapvz.common import phases
+from bootstrapvz.common.tasks import packages
+from bootstrapvz.common.tasks import apt
+from bootstrapvz.common.tools import log_check_call
+from bootstrapvz.common.tools import sed_i
+import os
+import urllib
+
+
+class InstallSaltDependencies(Task):
+	description = 'Add depended packages for salt-minion'
+	phase = phases.package_installation
+	predecessors = [apt.AddDefaultSources]
+
+	@classmethod
+	def run(cls, info):
+		info.packages.add('curl')
+		info.packages.add('ca-certificates')
+
+
+class BootstrapSaltMinion(Task):
+	description = 'Installing salt-minion using the bootstrap script'
+	phase = phases.package_installation
+	predecessors = [packages.InstallPackages]
+
+	@classmethod
+	def run(cls, info):
+		# Download bootstrap script
+		bootstrap_script = os.path.join(info.root, 'install_salt.sh')
+		with open(bootstrap_script, 'w') as f:
+			d = urllib.urlopen('http://bootstrap.saltstack.org')
+			f.write(d.read())
+
+		# This is needed since bootstrap doesn't handle -X for debian distros properly.
+		# We disable checking for running services at end since we do not start them.
+		sed_i(
+			bootstrap_script, 'install_debian_check_services',
+			"disabled_debian_check_services")
+
+		bootstrap_command = [
+			'chroot', info.root, 'bash', 'install_salt.sh', '-X']
+
+		if 'master' in info.manifest.plugins['salt']:
+			bootstrap_command.extend(['-A', info.manifest.plugins['salt']['master']])
+
+		install_source = info.manifest.plugins['salt']['install_source']
+
+		bootstrap_command.append(install_source)
+		if install_source == 'git' and ('version' in info.manifest.plugins['salt']):
+			bootstrap_command.append(info.manifest.plugins['salt']['version'])
+		log_check_call(bootstrap_command)
+
+
+class SetSaltGrains(Task):
+	description = 'Set custom salt grains'
+	phase = phases.system_modification
+
+	@classmethod
+	def run(cls, info):
+		grains_file = os.path.join(info.root, 'etc/salt/grains')
+		grains = info.manifest.plugins['salt']['grains']
+		with open(grains_file, 'a') as f:
+			for g in grains:
+				f.write('%s: %s\n' % (g, grains[g]))