image.py

# -*- python -*-
# -*- coding: utf-8 -*-
# Started 10/05/2011 by Seblu <seblu@seblu.net>

'''
Image stuff
'''

import os
import stat
import time
import json
import difflib
import ConfigParser
import subprocess
import re
import shutil
import gzip
import gzipstream #until python support gzip not seekable
import cStringIO
import installsystems
import installsystems.template as istemplate
import installsystems.tools as istools
import installsystems.tarfile as tarfile #until python2.7 is default
from installsystems.printer import *
from installsystems.tools import PipeFile
from installsystems.tarball import Tarball


class Image(object):
    '''
    Abstract class of images
    '''

    format = "1"
    extension = ".isimage"

    @staticmethod
    def check_image_name(buf):
        '''
        Check if @buf is a valid image name
        '''
        if re.match("^[-_\w]+$", buf) is None:
            raise Exception("Invalid image name %s" % buf)

    @staticmethod
    def check_image_version(buf):
        '''
        Check if @buf is a valid image version
        '''
        if re.match("^\d+$", buf) is None:
            raise Exception("Invalid image version %s" % buf)

    @staticmethod
    def compare_versions(v1, v2):
        '''
        Compare v1 and v2
        return > 0 if v1 > v2
        return < 0 if v2 > v1
        return = 0 if v1 == v2
        '''
        # check v1
        try:
            i1 = int(v1)
        except ValueError:
            if isinstance(v1, basestring):
                v1m = re.search("\d+", v1)
                if v1m is None:
                    raise Exception("Invalid version %s" % v1)
                i1 = int(v1m.group(0))
        # check v2
        try:
            i2 = int(v2)
        except ValueError:
            if isinstance(v2, basestring):
                v2m = re.search("\d+", v1)
                if v2m is None:
                    raise Exception("Invalid version %s" % v2)
                i2 = int(v2m.group(0))
        return i1 - i2


class SourceImage(Image):
    '''
    Image source manipulation class
    '''

    @classmethod
    def create(cls, path, force=False):
        '''
        Create an empty source image
        '''
        # check local repository
        if not istools.isfile(path):
            raise NotImplementedError("SourceImage must be local")
        # main path
        parser_path = os.path.join(path, "parser")
        setup_path = os.path.join(path, "setup")
        payload_path = os.path.join(path, "payload")
        # create base directories
        arrow("Creating base directories")
        try:
            for d in (path, parser_path, setup_path, payload_path):
                if not os.path.exists(d) or not os.path.isdir(d):
                    os.mkdir(d)
        except Exception as e:
            raise Exception("Unable to create directory: %s: %s" % (d, e))
        # create example files
        arrow("Creating examples")
        arrowlevel(1)
        # create dict of file to create
        examples = {}
        # create description example from template
        examples["description"] = {"path": "description",
                                   "content": istemplate.description % {
                "name": "",
                "version": "1",
                "description": "",
                "author": "",
                "is_min_version": installsystems.version}}
        # create changelog example from template
        examples["changelog"] = {"path": "changelog", "content": istemplate.changelog}
        # create parser example from template
        examples["parser"] = {"path": "parser/01-parser.py", "content": istemplate.parser}
        # create setup example from template
        examples["setup"] = {"path": "setup/01-setup.py", "content": istemplate.setup}
        for name in examples:
            try:
                arrow("Creating %s example" % name)
                expath = os.path.join(path, examples[name]["path"])
                if not force and os.path.exists(expath):
                    warn("%s already exists. Skipping!" % expath)
                    continue
                open(expath, "w").write(examples[name]["content"])
            except Exception as e:
                raise Exception("Unable to create example file: %s" % e)
        try:
            # setting executable rights on files in setup and parser
            arrow("Setting executable rights on scripts")
            umask = os.umask(0)
            os.umask(umask)
            for dpath in (parser_path, setup_path):
                for f in os.listdir(dpath):
                    istools.chrights(os.path.join(dpath, f), mode=0777 & ~umask)
        except Exception as e:
            raise Exception("Unable to set rights on %s: %s" % (pf, e))
        arrowlevel(-1)

    def __init__(self, path):
        # check local repository
        if not istools.isfile(path):
            raise NotImplementedError("SourceImage must be local")
        Image.__init__(self)
        self.base_path = path
        self.parser_path = os.path.join(path, "parser")
        self.setup_path = os.path.join(path, "setup")
        self.payload_path = os.path.join(path, "payload")
        self.validate_source_files()
        self.description = self.parse_description()
        self.changelog = self.parse_changelog()
        # script tarball path
        self.image_name = "%s-%s%s" % (self.description["name"],
                                       self.description["version"],
                                       self.extension)

    def validate_source_files(self):
        '''
        Check if we are a valid SourceImage directories
        '''
        for d in (self.base_path, self.parser_path, self.setup_path, self.payload_path):
            if not os.path.exists(d):
                raise Exception("Missing directory: %s" % d)
            if not os.path.isdir(d):
                raise Exception("Not a directory: %s" % d)
            if not os.access(d, os.R_OK|os.X_OK):
                raise Exception("Unable to access to %s" % d)
        if not os.path.exists(os.path.join(self.base_path, "description")):
            raise Exception("No description file")

    def build(self, force=False, check=True):
        '''
        Create packaged image
        '''
        # check if free to create script tarball
        if os.path.exists(self.image_name) and force == False:
            raise Exception("Tarball already exists. Remove it before")
        # Check python file
        if check:
            self.check_scripts(self.parser_path)
            self.check_scripts(self.setup_path)
        # Create payload files
        payloads = self.create_payloads()
        # generate a JSON description
        jdesc = self.generate_json_description(payloads)
        # creating scripts tarball
        self.create_image(jdesc)

    def create_image(self, jdescription):
        '''
        Create a script tarball in current directory