hexagonit.recipe.download 1.4.1

1.4.1 (2010-04-08)

• Implemented support for specifying the filename of a downloaded file when using download-only = true. This closes http://github.com/hexagonit/hexagonit.recipe.download/issues#issue/3 [dokai]

• Fixed the filename handling for download-only = true. The filename hashing introduced in 1.4.0 resulted in the names of the downloaded files to be hashed also. Now the original filename is preserved regardless whether filenames are hashed in the download cache. This closes http://github.com/hexagonit/hexagonit.recipe.download/issues#issue/2 [dokai]

1.4.0 (2010-04-06)

• Changed the download policy to hash the downloaded filenames by default. You can revert back to the original behavior by setting a hash-name = false parameter in the section using the recipe. This closes http://github.com/hexagonit/hexagonit.recipe.download/issues#issue/1 [dokai]

1.3.0 (2009-09-20)

• Removed support for the deprecated download-directory option. [dokai]

• Refactored the download logic to use the Download API in zc.buildout. We now require zc.buildout >= 1.4.0. [dokai]

1.2.2 (2009-08-17)

• Merged the current trunk (revision 79982) from the Plone Collective Subversion repository. The collective repository is now abandoned and the Github repository is the canonical one. [dokai]

• Open files in binary mode when calculating MD5 checksums. This fixes a bug with checksums on the Windows platform. Bug report and patch thanks to Alexander Ivanov. [dokai]

1.2.1 (2008-04-13)

• Rename the buildout download-directory option to download-cache (which is the name used by buildout) [thefunny]

• Added BBB support for the download-directory option. It will emit a deprecation warning and set the download-cache option accordingly. [dokai]

1.2.0 (2008-01-19)

• Added the download-only option to allow downloading arbitrary files. [dokai]

1.1.0 (2007-10-14)

• Refactored the install method so recipe subclasses can override the base directory. For more info see calculate_base method on Recipe class. [hexsprite]

• Recipe is now a new-style Python class so recipe subclasses can use super() method to get some default behavior. [hexsprite]

1.0.1 (2007-08-14)

• For consistency with other similar recipes, the recipe now sets a location option which may be read by other sections to learn where the package was extracted. This is an alias for the destination option.

1.0.0

• First public release.

Supported options

The hexagonit.recipe.download recipe can be used to download and extract packages from the net. It supports the following options:

url

URL to the package that will be downloaded and extracted. The supported package formats are .tar.gz, .tar.bz2, and .zip. The value must be a full URL, e.g. http://python.org/ftp/python/2.4.4/Python-2.4.4.tgz.

strip-top-level-dir

Switch to remove the top level directory from the extracted archive. This will work only if the archive has exactly one top level directory. Accepted values are ‘true’ or ‘false’. Defaults to ‘false’.

ignore-existing

Switch to ignore existing files and/or directories. By default, the extraction process fails if there is existing files or directories matching the ones from the archive. Enabling this option will skip these files/directories from the archive. When this recipe is uninstalled the ignored files/directories will not be removed. Accepted values are ‘true’ or ‘false’. Defaults to ‘false’.

md5sum

MD5 checksum for the package file. If available the MD5 checksum of the downloaded package will be compared to this value and if the values do not match the execution of the recipe will fail.

destination

Path to a directory where the extracted contents of the package will be placed. If omitted, a directory will be created under the buildout['parts-directory'] with the name of the section using the recipe.

download-only

When set to ‘true’, the recipe downloads the file without trying to extract it. This is useful for downloading non-tarball files. The strip-top-level-dir option will be ignored if this option is enabled. Defaults to false.

filename

Allows renaming the downloaded file when using download-only = true. The downloaded file will still be placed under the destination directory with the given filename. If download-only = false this option will be ignored. By default the original filename will be used. New in version 1.4.1.

hash-name

When set to ‘true’, passes the hash_name=True keyword parameter to the zc.buildout Download utility which in turn uses MD5 hashes to name the downloaded files. See the corresponding documentation for details. Setting the parameter to false will use the original filename. Defaults to true. New in version 1.4.0.

The recipe uses the zc.buildout Download API to perform the actual download which allows additional configuration of the download process.

By default, the recipe sets the download-cache option to ${buildout:directory}/downloads and creates the directory if necessary. This can be overridden by providing the download-cache option in your [buildout] section.

Simple example

>>> import os.path
>>> testdata = join(os.path.dirname(__file__), 'testdata')
>>> server = start_server(testdata)

In the simplest form we can download a simple package and have it extracted in the parts directory.

>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %spackage1-1.2.3-final.tar.gz
... """ % server)

Ok, let’s run the buildout:

>>> print system(buildout)
Installing package1.
Downloading http://test.server/package1-1.2.3-final.tar.gz
package1: Extracting package to /sample-buildout/parts/package1

Let’s take a look at the buildout parts directory now.

>>> ls(sample_buildout, 'parts')
d package1

The containing directory is named after our part name. Within this directory are the contents of the extracted package.

>>> ls(sample_buildout, 'parts', 'package1')
d package1-1.2.3-final

The package contained a single top level directory. Let’s peek what’s inside.

>>> ls(sample_buildout, 'parts', 'package1', 'package1-1.2.3-final')
- CHANGES.txt
- README.txt
d src

>>> rmdir('downloads')

Sharing packages between buildouts

Using the download-cache option in the buildout allows you to store the downloaded packages in central location on your filesystem. Using the the same location for the download-cache in multiple buildouts will effectively share the packages between them and reduce the network traffic and storage requirements.

Let’s create a directory to be used as the download cache.

>>> cache = tmpdir('cache')

And create a new buildout that sets the buildout-cache option accordingly.

>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = sharedpackage
... download-cache = %(cache)s
...
... [sharedpackage]
... recipe = hexagonit.recipe.download
... url = %(server)spackage1-1.2.3-final.tar.gz
... """ % dict(cache=cache, server=server))

Ok, let’s run the buildout:

>>> print system(buildout)
Uninstalling package1.
Installing sharedpackage.
Downloading http://test.server/package1-1.2.3-final.tar.gz
sharedpackage: Extracting package to /sample-buildout/parts/sharedpackage

We can see that the package was placed under the shared container instead of the default location under the buildout directory. By default the the filename of the downloaded package is hashed.

>>> ls(cache)
-  dfb1e3136ba092f200be0f9c57cf62ec
d  dist

We can keep the original filename by setting the hash-name parameter to false. For readability all the following examples will have hashing disabled.

MD5 checksums

The downloaded package can be verified against an MD5 checksum. This will make it easier to spot problems if the file has been changed.

If the checksum fails we get an error.

>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %spackage1-1.2.3-final.tar.gz
... md5sum = invalid
... hash-name = false
... """ % server)

>>> print system(buildout)
Uninstalling sharedpackage.
Installing package1.
Downloading http://test.server/package1-1.2.3-final.tar.gz
While:
  Installing package1.
Error: MD5 checksum mismatch downloading 'http://test.server/package1-1.2.3-final.tar.gz'

Using a valid checksum allows the recipe to proceed.

>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %s/package1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... hash-name = false
... """ % server)

>>> print system(buildout)
Installing package1.
Downloading http://test.server//package1-1.2.3-final.tar.gz
package1: Extracting package to /sample-buildout/parts/package1

Controlling the extraction process

We can also extract the archive to any arbitrary location and have the top level directory be stripped, which is often a useful feature.

>>> tmpcontainer = tmpdir('otherplace')
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %(server)s/package1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... destination = %(dest)s
... strip-top-level-dir = true
... hash-name = false
... """ % dict(server=server, dest=tmpcontainer))

Rerunning the buildout now gives us

>>> print system(buildout)
Uninstalling package1.
Installing package1.
package1: Extracting package to /otherplace

Taking a look at the extracted contents we can also see that the top-level directory has been stripped.

>>> ls(tmpcontainer)
- CHANGES.txt
- README.txt
d src

Partial extraction over existing content

By default, the recipe will fail if the destination where the package will be extracted already contains files or directories also included in the package.

>>> container = tmpdir('existing')
>>> existingdir = mkdir(container, 'src')

>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %(server)s/package1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... destination = %(dest)s
... strip-top-level-dir = true
... hash-name = false
... """ % dict(server=server, dest=container))

Running the buildout now will fail because of the existing src directory in the destination.

>>> print system(buildout)
Uninstalling package1.
Installing package1.
package1: Extracting package to /existing
package1: Target /existing/src already exists. Either remove it or set ``ignore-existing = true`` in your buildout.cfg to ignore existing files and directories.
While:
  Installing package1.
Error: File or directory already exists.

Setting the ignore-existing option will allow the recipe to proceed.

>>> rmdir(container)
>>> container = tmpdir('existing')
>>> existingdir = mkdir(container, 'src')

>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %(server)s/package1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... destination = %(dest)s
... strip-top-level-dir = true
... ignore-existing = true
... hash-name = false
... """ % dict(server=server, dest=container))

>>> print system(buildout)
Installing package1.
package1: Extracting package to /existing
package1: Ignoring existing target: /existing/src

>>> ls(container)
- CHANGES.txt
- README.txt
d src

Also note that when the recipe is uninstalled the ignored targets will not be removed as they are not part of the output of this recipe. We can verify this by running the buildout again with a different destination.

>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %(server)s/package1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... strip-top-level-dir = true
... ignore-existing = true
... hash-name = false
... """ % dict(server=server))

>>> print system(buildout)
Uninstalling package1.
Installing package1.
package1: Extracting package to /sample-buildout/parts/package1

Now when we look into the directory containing the previous buildout we can see that the src directory is still there but the rest of the files are gone.

>>> ls(container)
d src

Offline mode

If the buildout is run in offline mode the recipe will still work if the package is cached in the downloads directory. Otherwise the user will be informed that downloading the file is not possible in offline mode.

>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
... offline = true
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %(server)s/package1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... strip-top-level-dir = true
... hash-name = false
... """ % dict(server=server))

Let’s verify that we do have a cached copy in our downloads directory.

>>> ls(sample_buildout, 'downloads')
-  package1-1.2.3-final.tar.gz

>>> print system(buildout)
Uninstalling package1.
Installing package1.
package1: Extracting package to /sample-buildout/parts/package1

When we remove the file from the filesystem the recipe will not work.

>>> remove(sample_buildout, 'downloads', 'package1-1.2.3-final.tar.gz')
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package1
... offline = true
...
... [package1]
... recipe = hexagonit.recipe.download
... url = %(server)spackage1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... hash-name = false
... """ % dict(server=server))

>>> print system(buildout)
Uninstalling package1.
Installing package1.
While:
  Installing package1.
Error: Couldn't download 'http://test.server/package1-1.2.3-final.tar.gz' in offline mode.

Downloading arbitrary files

We can download any file when setting the download-only option to true. This will simply place the file in the destination directory.

>>> empty_download_cache(cache)
>>> downloads = tmpdir('my-downloads')
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package
... download-cache = %(cache)s
...
... [package]
... recipe = hexagonit.recipe.download
... url = %(server)spackage1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... destination = %(dest)s
... download-only = true
... """ % dict(server=server, dest=downloads, cache=cache))

>>> print system(buildout)
Installing package.
Downloading http://test.server/package1-1.2.3-final.tar.gz

Looking into the destination directory we can see that the file was downloaded but not extracted. Using the download-only option will work for any file regardless of the type.

>>> ls(downloads)
-  package1-1.2.3-final.tar.gz

As seen above, with download-only the original filename will be preserved regardless whether filename hashing is in use or not. However, the cached copy will be hashed by default.

>>> ls(cache)
-  dfb1e3136ba092f200be0f9c57cf62ec
d  dist

The downloaded files may also be renamed to better reflect their purpose using the filename parameter.

>>> empty_download_cache(cache)
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package
... download-cache = %(cache)s
...
... [package]
... recipe = hexagonit.recipe.download
... url = %(server)spackage1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... destination = %(dest)s
... download-only = true
... filename = renamed-package-1.2.3.tgz
... """ % dict(server=server, dest=downloads, cache=cache))

>>> print system(buildout)
Uninstalling package.
Installing package.
Downloading http://test.server/package1-1.2.3-final.tar.gz

>>> ls(downloads)
-  renamed-package-1.2.3.tgz

Variable substitions may be used with the filename parameter to generate the resulting filename dynamically.

>>> empty_download_cache(cache)
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... newest = false
... parts = package
... download-cache = %(cache)s
... example = foobar-1.2.3
...
... [package]
... recipe = hexagonit.recipe.download
... url = %(server)spackage1-1.2.3-final.tar.gz
... md5sum = 821ecd681758d3fc03dcf76d3de00412
... destination = %(dest)s
... download-only = true
... filename = ${:_buildout_section_name_}-${buildout:example}.tgz
... """ % dict(server=server, dest=downloads, cache=cache))

>>> print system(buildout)
Uninstalling package.
Installing package.
Downloading http://test.server/package1-1.2.3-final.tar.gz

In this example we have used the section name and a value from the [buildout] section to demonstrate the dynamic naming.

>>> ls(downloads)
-  package-foobar-1.2.3.tgz