updater.py

#!/usr/bin/python
# Copyright 2013 BrewPi
# This file is part of BrewPi.

# BrewPi is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# BrewPi is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with BrewPi. If not, see <http://www.gnu.org/licenses/>.

### Geo Van O, v0.9, Sep 2013
### Elco Jacobs, sept 2013

import subprocess
from time import localtime, strftime
import sys
import os
import urllib2
import getopt

try:
    import git
except ImportError:
    print "This update script requires gitpython, please install it with 'sudo pip install gitpython"
    sys.exit(1)


# Read in command line arguments
try:
    opts, args = getopt.getopt(sys.argv[1:], "a", ['ask'])
except getopt.GetoptError:
    print ("Unknown parameter, available options: \n" +
          "  updater.py --ask\t\t do not use default options, but ask me which branches to check out")
    sys.exit()

userInput = False
for o, a in opts:
    # print help message for command line options
    if o in ('-a', '--ask'):
        print "\nUsing interactive (advanced) update with user input \n\n"
        userInput = True


### Quits all running instances of BrewPi
def quitBrewPi(webPath):
    print "\nStopping running instances of BrewPi"
    import BrewPiProcess
    allProcesses = BrewPiProcess.BrewPiProcesses()
    allProcesses.stopAll(webPath+"/do_not_run_brewpi")

# remove do_not_run file
def startBrewPi(webPath):
    filePath = webPath+"/do_not_run_brewpi"
    if os.path.isfile(filePath):
        os.remove(filePath)


### calls update-tools-repo, which returns 0 if the brewpi-tools repo is up-to-date
def checkForUpdates():
    if os.path.exists(os.path.dirname(os.path.realpath(__file__)) + "/update-tools-repo.sh"):
        try:
            print "Checking whether the update script is up to date"
            subprocess.check_call(["sudo", "bash", os.path.dirname(os.path.realpath(__file__)) + "/update-tools-repo.sh"],
                                  stderr=subprocess.STDOUT)
        except subprocess.CalledProcessError:
            print "This script was not up-to-date and has been automatically updated. Please re-run updater.py."
            sys.exit(1)
    else:
        print "The required file update-this-repo.sh was not found. This is likely to occur if you manually copied updater.py here.\n"+ \
            "Please run this from the original location you installed the brewpi-tools git repo and try again."
        sys.exit(1)


### call installDependencies.sh, so commands are only defined in one place.
def runAfterUpdate(scriptDir):
    try:
        print "Installing dependencies, updating CRON and fixing file permissions..."
        subprocess.check_call(["sudo", "bash", scriptDir + "/utils/runAfterUpdate.sh"], stderr=subprocess.STDOUT)
    except subprocess.CalledProcessError:
        print "I tried to execute the runAfterUpdate.sh bash script, but an error occurred. " + \
              "Try running it from the command line in your <brewpi-script>/utils dir"

### Stash any local repo changes
def stashChanges(repo):
    print "\nYou have local changes in this repository, that are prevent a successful merge."
    print "These changes can be stashed to bring your repository back to its original state so we can merge."
    print "Your changes are not lost, but saved on the stash." +\
          "You can (optionally) get them back later with 'git stash pop'."
    choice = raw_input("Would you like to stash local changes? (Required to continue) [Y/n]: ")
    if any(choice == x for x in ["", "yes", "Yes", "YES", "yes", "y", "Y"]):
        print "Attempting to stash any changes...\n"
        try:
            repo.git.config('--get', 'user.name')
        except git.GitCommandError, e:
            print "Warning: No user name set for git, which is necessary to stash."
            userName = raw_input("--> Please enter a global username for git on this system (just make something up): ")
            repo.git.config('--global', 'user.name', userName)
        try:
            repo.git.config('--get', 'user.email')
        except git.GitCommandError, e:
            print "Warning: No user e-mail address set for git, which is necessary to stash."
            userEmail = raw_input("--> Please enter a global user e-mail address for git on this system: ")
            repo.git.config('--global', 'user.email', userEmail)
        try:
            resp = repo.git.stash()
            print "\n" + resp + "\n"
            print "Stash successful"

            print "##################################################################"
            print "#Your local changes were in conflict with the last update of code.#"
            print "##################################################################"
            print "The conflict was:\n"
            print "-------------------------------------------------------"
            print  repo.git.stash("show", "--full-diff", "stash@{0}")
            print "-------------------------------------------------------"
            print ""
            print  ("To make merging possible, these changes were stashed." +
                    "To merge the changes back in, you can use 'git stash pop'."
                    "Only do this if you really know what you are doing!" +
                    "Your changes might be incompatible with the update or could cause a new merge conflict.")

            return True
        except git.GitCommandError, e:
            print e
            print "Unable to stash, don't want to overwrite your stuff, aborting this branch update"
            return False
    else:
        print "Changes are not stashed, cannot continue without stashing. Aborting update"
        return False


### Function used to stash local changes and update a branch passed to it
def update_repo(repo, remote, branch):
    stashed = False
    repo.git.fetch(remote, branch)
    try:
        print repo.git.merge(remote + '/' + branch)
    except git.GitCommandError, e:
        print e
        if "Your local changes to the following files would be overwritten by merge" in str(e):
            stashed = stashChanges(repo)
            if not stashed:
                return False

        print "Trying to merge again..."
        try:
            print repo.git.merge(remote + '/' + branch)
        except git.GitCommandError, e:
            print e
            print "Sorry, cannot automatically stash/discard local changes. Aborting"
            return False


    print branch + " updated!"
    return True


### Function to be used to check most recent commit date on the repo passed to it
def check_repo(repo):
    updated = False
    localBranch = repo.active_branch.name
    newBranch = localBranch
    remoteRef = None

    print "You are on branch " + localBranch

    if localBranch != "master" and not userInput:
        print "Your checked out branch is not master, our stable release branch."
        choice = raw_input("It is highly recommended that you switch to the stable master branch."
                          " Would you like to do that? [Y/n]:")
        if any(choice == x for x in ["", "yes", "Yes", "YES", "yes", "y", "Y"]):
            print "Switching branch to master"
            newBranch = "master"


    ### Get available remotes
    remote = repo.remotes[0] # default to first found remote
    if userInput and len(repo.remotes) > 1:
        print "Multiple remotes found in " + repo.working_tree_dir
        for i, rem in enumerate(repo.remotes):
            print "[%d] %s" % (i, rem.name)
        print "[" + str(len(repo.remotes)) + "] Skip updating this repository"
        while 1:
            try:
                choice = raw_input("From which remote do you want to update? [%s]:" % remote)
                if choice == "":
                    print "Updating from default remote %s" % remote
                    break
                else:
                    selection = int(choice)
            except ValueError:
                print "Use the number!"
                continue
            if selection == len(repo.remotes):
                return False # choice = skip updating
            try:
                remote = repo.remotes[selection]
            except IndexError:
                print "Not a valid selection. Try again"
                continue
            break

    repo.git.fetch(remote.name, "--prune")

    ### Get available branches on the remote
    try:
        remoteBranches = remote.refs
    except AssertionError as e:
        print "Failed to get references from remote: " + repr(e)
        print "Aborting update of " + repo.working_tree_dir
        return False

    if userInput:
        print "\nAvailable branches on the remote '%s' for %s:" % (remote.name, repo.working_tree_dir)

    for i, ref in enumerate(remoteBranches):
        remoteRefName = "%s" % ref
        if "/HEAD" in remoteRefName:
            remoteBranches.pop(i)  # remove HEAD from list

    for i, ref in enumerate(remoteBranches):
        remoteRefName = "%s" % ref
        remoteBranchName = remoteRefName.replace(remote.name + "/", "")
        if remoteBranchName == newBranch:
            remoteRef = ref
        if userInput:
            print "[%d] %s" % (i, remoteBranchName)

    if userInput:
        print "[" + str(len(remoteBranches)) + "] Skip updating this repository"

        while 1:
            try:
                choice = raw_input("Enter the number of the branch you wish to update [%s]:" % localBranch)
                if choice == "":
                    print "Keeping current branch %s" % localBranch
                    break
                else:
                    selection = int(choice)
            except ValueError:
                print "Use the number!"
                continue
            if selection == len(remoteBranches):
                return False # choice = skip updating
            try:
                remoteRef = remoteBranches[selection]
            except IndexError:
                print "Not a valid selection. Try again"
                continue
            break

    if remoteRef is None:
        print "Could not find branch selected branch on remote! Aborting"
        return False

    remoteBranch = ("%s" % remoteRef).replace(remote.name + "/", "")

    checkedOutDifferentBranch = False
    if localBranch != remoteBranch:
        choice = raw_input("The " + remoteBranch + " branch is not your currently active branch - " +
                           "would you like me to check it out for you now? (Required to continue) [Y/n]: ")
        if any(choice == x for x in ["", "yes", "Yes", "YES", "yes", "y", "Y"]):
            stashedForCheckout = False
            while True:
                try:
                    if remoteBranch in repo.branches:
                        print repo.git.checkout(remoteBranch)
                    else:
                        print repo.git.checkout(remoteRef, b=remoteBranch)
                    print "Successfully switched to " + remoteBranch
                    checkedOutDifferentBranch = True
                    break
                except git.GitCommandError, e:
                    if not stashedForCheckout:
                        if "Your local changes to the following files would be overwritten by checkout" in str(e):
                            print "Local changes exist in your current files that need to be stashed to continue"
                            if not stashChanges(repo):
                                return
                            print "Trying to checkout again..."
                            stashedForCheckout = True # keep track of stashing, so it is only tried once
                            continue # retry after stash
                    else:
                        print e
                        print "I was unable to checkout. Please try it manually from the command line and re-run this tool"
                        return False
        else:
            print "Skipping this branch"
            return False

    if remoteRef is None:
        print "Error: Could not determine which remote reference to use, aborting"
        return False

    localDate = repo.head.commit.committed_date
    localDateString = strftime("%a, %d %b %Y %H:%M:%S", localtime(localDate))
    localSha = repo.head.commit.hexsha
    localName = repo.working_tree_dir

    remoteDate = remoteRef.commit.committed_date
    remoteDateString = strftime("%a, %d %b %Y %H:%M:%S", localtime(remoteDate))
    remoteSha = remoteRef.commit.hexsha
    remoteName = remoteRef.name
    alignLength = max(len(localName), len(remoteName))

    print "The latest commit in " + localName.ljust(alignLength) + " is " + localSha + " on " + localDateString
    print "The latest commit on " + remoteName.ljust(alignLength) + " is " + remoteSha + " on " + remoteDateString

    if localDate < remoteDate:
        print "*** Updates are available! ****"
        choice = raw_input("Would you like to update " + localName + " from " + remoteName + " [Y/n]: ")
        if any(choice == x for x in ["", "yes", "Yes", "YES", "yes", "y", "Y"]):
            updated = update_repo(repo, remote.name, remoteBranch)
    else:
        print "Your local version of " + localName + " is up to date!"
    return updated or checkedOutDifferentBranch


print "######################################################"
print "####                                              ####"
print "####        Welcome to the BrewPi Updater!        ####"
print "####                                              ####"
print "######################################################"
print ""

if os.geteuid() != 0:
    print "This update script should be run as root."
    print "Try running it gain with sudo, exiting..."
    exit(1)

checkForUpdates()
print ""

changed = False
scriptPath = '/home/brewpi'
webPath = '/var/www'

print "\n\n*** Updating BrewPi script repository ***"

for i in range(3):
    correctRepo = False
    try:
        scriptRepo = git.Repo(scriptPath)
        gitConfig = open(scriptPath + '/.git/config', 'r')
        for line in gitConfig:
            if "url =" in line and "brewpi-script" in line:
                correctRepo = True
                break
        gitConfig.close()
    except git.NoSuchPathError:
        print "The path '%s' does not exist" % scriptPath
        scriptPath = raw_input("What path did you install the BrewPi python scripts to?")
        continue
    except (git.InvalidGitRepositoryError, IOError):
        print "The path '%s' does not seem to be a valid git repository" % scriptPath
        scriptPath = raw_input("What path did you install the BrewPi python scripts to?")
        continue

    if not correctRepo:
        print "The path '%s' does not seem to be the BrewPi python script git repository" % scriptPath
        scriptPath = raw_input("What path did you install the BrewPi python scripts to?")
        continue
    ### Add BrewPi repo into the sys path, so we can import those modules as needed later
    sys.path.insert(0, scriptPath)
    quitBrewPi(webPath) # exit running instances of BrewPi
    changed = check_repo(scriptRepo) or changed
    break
else:
    print "Maximum number of tries reached, updating BrewPi scripts aborted"

print "\n\n*** Updating BrewPi web interface repository ***"
for i in range(3):
    correctRepo = False
    try:
        webRepo = git.Repo(webPath)
        gitConfig = open(webPath + '/.git/config', 'r')
        for line in gitConfig:
            if "url =" in line and "brewpi-www" in line:
                correctRepo = True
                break
        gitConfig.close()
    except git.NoSuchPathError:
        print "The path '%s' does not exist" % webPath
        webPath = raw_input("What path did you install the BrewPi web interface scripts to? ")
        continue
    except (git.InvalidGitRepositoryError, IOError):
        print "The path '%s' does not seem to be a valid git repository" % webPath
        webPath = raw_input("What path did you install the BrewPi web interface scripts to? ")
        continue
    if not correctRepo:
        print "The path '%s' does not seem to be the BrewPi web interface git repository" % webPath
        webPath = raw_input("What path did you install the BrewPi web interface scripts to? ")
        continue
    changed = check_repo(webRepo) or changed
    break
else:
    print "Maximum number of tries reached, updating BrewPi web interface aborted"

if changed:
    print "\nOne our more repositories were updated, running runAfterUpdate.sh from %s/utils..." % scriptPath
    runAfterUpdate(scriptPath)
else:
    print "\nNo changes were made, skipping runAfterUpdate.sh."
    print "If you encounter problems, you can start it manually with:"
    print "sudo %s/utils/runAfterUpdate.sh" % scriptPath

choice = raw_input("\nThe update script can automatically check your controller firmware version and " +
                   "program it with the latest release on GitHub, would you like to do this now? [Y/n]:")
if any(choice == x for x in ["", "yes", "Yes", "YES", "yes", "y", "Y"]):
    try:
        sys.path.append(scriptPath + "/utils")  # append directory to be able to import files
        import updateFirmware
    except:
        print "Could not find updateFirmware.py in the script directory, is it up-to-date?"
    updateFirmware.updateFromGitHub(userInput) # update and restore settings, do not prompt user
else:
    print "Skipping controller update"

startBrewPi(webPath)
print "\n\n*** Done updating BrewPi! ***\n"