ruby - 应用引擎 : Launching a script upon update/run

Question

我正在使用 App Engine，我正在考虑在我的下一个项目中使用 LESS CSS 扩展。没有用 Python 编写的好的 LESS CSS 库，所以我继续使用原始的 Ruby 库，它工作得很好而且开箱即用。我希望 App Engine 在运行开发服务器之前和将文件上传到云端之前执行 lessc ./templates/css/style.less。自动化这个的最好方法是什么？我在想:

#run.sh:
lessc ./templates/css/style.less
.gae/dev_appserver.py --use_sqlite .

和

#deploy.sh
lessc ./templates/css/style.less
.gae/appcfg.py update .

我是在正确的道路上还是有更优雅的做事方式，也许在 appcfg.py 级别？

谢谢。

Answer 1

一种选择是使用 Less 的 javascript 版本，从而在浏览器中进行 less 到 css 的转换。只需上传您的 less 格式的文件(详情请参阅 http://lesscss.org/)。

或者，我在执行许多操作的部署脚本中进行转换(首先使用 less，现在我使用 sass)

• 检查我的源代码控制是否没有 checkout 未完成的文件(未提交的更改)
• 将我的 .js 代码(并在其上运行 jslint)合并并缩小到一个文件中
• 生成其他内容(包括将源代码控制版本作为版本号标记到某些关键文件中，并作为某些文件的参数以避免缓存问题)所以我的主页会引入带有 URL 的脚本，例如“allmysource.js? v=585".. 该文件可能是静态的，但添加的参数强制缓存失效
• 调用 appcfg 执行上传并检查返回码
• 使用 wget 调用真实站点来检查之前生成的文件是否实际返回，方法是检查它们是否标记了预期的版本
• 应用另一个源代码控制标签来表示预期版本已成功部署

我的脚本还接受一个“-preview”标志，在这种情况下它实际上并不进行上传，而是报告自上次部署以来更改内容的版本控制评论。

me@here $ ./deploy -preview
Deployment preview...
Would deploy v596 to the production site (currently v593, previously v587)
  594       Fix blah blah blah for X Y Z
  595       New feature nah nah nah 
  596       Update help pages

这非常方便，可以提醒我需要在更新日志中添加什么

我还计划扩展它，这样我就可以作为我的源代码控制的一部分，添加任何只在部署时需要运行一次的代码(例如数据库架构更改)，并且知道它会在我下次运行时自动运行部署新版本。

正如人们所问的，下面脚本的本质......它没有显示我的“检查代码、生成、加入和缩小”，因为那是另一个脚本......我意识到最初的问题是询问那一步当然 :) 但你可以看到你在哪里添加生成 CSS 等的调用

#!/bin/sh

function abort () {
    echo
    echo "ERROR: $1"
    echo "$2"
    exit 99
}

function warn () {
    echo
    echo "WARNING: $1"
    echo "$2"
}

# Overrides the Gentoo eselect mechanism to force the python version the GAE scripts expect
export EPYTHON=python2.5

# names of tags used to label bzr versions    
CURR_DTAG=deployed
PREV_DTAG=prevDeployed

# command line options
PREVIEW=0
IGNORE_BZR=0

# These next few vars are set to values to identify my site, insert your own values here...
APPID=your_gae_appid_here
ADMIN_EMAIL=your_admin_email_address_here
SRCDIR=directory_to_deploy
CHECK_URL=url_of_page_to_retrive_that_does_upload_initialisation

for ARG; do
    if [[ "$ARG" == "-preview" ]]; then
        echo "Deployment preview..."
        PREVIEW=1
    fi
    if [[ "$ARG" == "-force" ]]; then
        echo "Ignoring the fact some files may not be committed to bzr..."
        IGNORE_BZR=1
    fi
done
echo

# check bzr for uncommited changed    
BSTATUS=`bzr status`
if [[ "$BSTATUS" != "" ]]; then
    if [[ "$IGNORE_BZR" == "0" ]]; then 
        abort "There are uncommited changes - commit/revert/ignore all files before deploying" "$BSTATUS"
    else
        warn  "There are uncommited changes" "$BSTATUS"
    fi
fi

# get version of numbers of last deployed etc
currver=`bzr log -l1 --line                | sed -e 's/: .*//'`
lastver=`bzr log -rtag:${CURR_DTAG} --line | sed -e 's/: .*//'`
prevver=`bzr log -rtag:${PREV_DTAG} --line | sed -e 's/: .*//'`
lastlog=`bzr log -l 1 --line gae/changelog | sed -e 's/: .*//'`

RELEASE_NOTES=`bzr log --short --forward -r $lastver..$currver \
    | perl -ne '$ver = $1 if /^ {0,4}(\d+) /; print "  $ver $_" if ($ver and /^ {5,}\w/)' \
    | grep -v "^ *$lastver "`

LOG_NOTES=`bzr log --short --forward -r $lastlog..$currver \
    | perl -ne '$ver = $1 if /^ {0,4}(\d+) /; print "  $ver $_" if ($ver and /^ {5,}\w/)' \
    | grep -v "^ *$lastlog "`

# Crude but old habit - BUGBUGBUG is a marker in the code for things to be fixed before deployment
echo "Checking code for outstanding issues before deployment"
BUGSTATUS=`grep BUGBUGBUG js/*js`
if [[ "$BUGSTATUS" != "" ]]; then
    if [[ "$IGNORE_BZR" == "0" ]]; then 
        abort "There are outstanding BUGBUGBUGs - fix them before deploying" "$BUGSTATUS"
    else
        warn  "There are outstanding BUGBUGBUGs" "$BUGSTATUS"
    fi
fi

echo
echo "Deploy v$currver to the production site (currently v$lastver, previously v$prevver)"
echo "$RELEASE_NOTES"
echo

if [[ "$currver" -gt "$lastlog" && "$lastver" -ne "$lastlog" ]]; then
    echo "Changes since the changelog was last updated"
    echo "$LOG_NOTES"
    echo
fi

if [[ "$IGNORE_BZR" == "0" && $lastver -ge $currver ]]; then
    abort "There don't appear to be any changes to deploy..."
fi

if [[ "$PREVIEW" == "1" ]]; then
    exit 0
fi

$EPYTHON -c "import ssl" \
    || abort "$EPYTHON can't find ssl module for $EPYTHON - download it from pypi and install with the inbuilt setup.py"

# REMOVED - call to my script that calls jslint, generates files and compresses JS etc
#   || abort "Generation of code failed"

/opt/google_appengine/appcfg.py --email=$ADMIN_EMAIL -v -A $APPID update $SRCDIR \
    || abort "Appcfg failed - upload presumably incomplete"

# move the tags to show we deployed properly
bzr tag -r $lastver --force ${PREV_DTAG}
bzr tag -r $currver --force ${CURR_DTAG}

echo
echo "Production site updated from v$lastver to v$currver (in turn from v$prevver)"
echo
echo "Now visiting $CHECK_URL to upload the source to the database"

# new version doesn't seem to always be there (may be caching by the webserver etc) to be uploaded into the database.. try again just in case
for cb in $RANDOM $RANDOM $RANDOM $RANDOM ; do
    prodver=`wget $CHECK_URL?_cb=$cb -q -O - | perl -ne 'print $1 if /^\s*Rev #(\d+)\s*$/'`
    if [[ "$currver" == "$prodver" ]]; then
        echo "OK: New version $prodver successfully deployed"
        exit 0
    fi
    echo "Retrying the upload of source to the database"
    sleep 5
done
abort "The new source doesn't seem to be loading into the database" "Try 'wget $CHECK_URL?_cb=$RANDOM -q -O -'"

它不是特别大或聪明，但它可以自动完成上传工作