AWS Lambda 上的 Python Wand 和 ImageMagick

Question

Trying to run Wand on AWS Lambda for some simple image manipulation.

So far I've:

1. created an instance that's identical to lambda environment

2. installed imagemagick from source

    wget ImageMagick cd ImageMagick-... ./configure --prefix=/home/ec2-user/im --without-x make && make install

3. set MAGICK_HOME to /home/ec2-user/im/

4. pip install wand

but when I try to import wand.image I get:

import wand.image
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ec2-user/cv/local/lib64/python2.7/site-packages/wand/image.py", line 20, in <module>
    from .api import MagickPixelPacket, libc, libmagick, library
  File "/home/ec2-user/cv/local/lib64/python2.7/site-packages/wand/api.py", line 206, in <module>
    'Try to install:\n  ' + msg)
ImportError: MagickWand shared library not found.
You probably had not installed ImageMagick library.
Try to install:
  http://docs.wand-py.org/en/latest/guide/install.html

It works fine when I do a yum install ImageMagick , but since I want to bundle it I thought I'd need to include the binary and point the wand installation to it.

Any thoughts?

Answer 1

Since someone else is interested now, I solved this issue and currently manage my lambda projects similar to below.

folder structure

-project
  -init_libs.py
  -lambda_function.py
  -libs
    -libMagickWand-6.Q16.so
    -libMagickCore-6.Q16.so
    -libMagick++-6.Q16.so
  -site-packages
    -wand
  -other_modules

init_libs.py loads native libraries like Wand.

import sys
import os
from ctypes import cdll
from os.path import join

# manually load libraries and set paths so native libraries can be used.
exec_dir = os.getcwd()
sys.path.append(join(exec_dir, 'site-packages'))

# required for Wand
os.environ['MAGICK_HOME'] = exec_dir

lib_dir = join(exec_dir, 'lib')

# add lib to sys path for general loading
sys.path.append(lib_dir)

lambda_function.py can now import wand

from wand.image import Image

print Image

Answer 2

This may not be helpful to the question asked, but if the desired goal is to do some simple file conversion (pdf to jpg/png etc.) one can bypass wand and invoke ImageMagick/GhostScript directly (these are packaged with the Python3.6 AWS environment).

eg

# converts local pdf to jpg using ImageMagick
os.system("convert -density 200x200 /tmp/in_pdf.pdf /tmp/out_jpg.jpg")

# converts local pdf to jpg using GhostScript
os.system(
        "gs -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT "
        "-dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 "
        "-sDEVICE=jpeg -dTextAlphaBits=4 -dGraphicsAlphaBits=4 -r150 "
        "-sOutputFile=/tmp/out_jpg-%d.jpg /tmp/in_pdf.pdf"
    )

The reason I am using /tmp as a file location is because lambda allows you to store files up to 500MB there during the running of the lambda function.

I hope this helps someone!

Answer 3

Inspired from https://gist.github.com/bensie/56f51bc33d4a55e2fc9a#gistcomment-3133859 , I was able to successfully package ImageMagick and Ghostscript in a Python 3.8 compatible AWS Lambda layer and use wand to convert the pages in a PDF into PNG by following these instructions:

1. Start an EC2 instance and SSH into it. I used the AMI amzn2-ami-hvm-2.0.20210126.0-x86_64-gp2 .
2. Download ImageMagick 6.9.11.

    wget https://download.imagemagick.org/ImageMagick/download/ImageMagick-6.9.11-60.tar.gz

3. Extract the folder.

    tar zxvf ImageMagick-6.9.11-60.tar.gz

4. cd into the extracted folder.

    cd ImageMagick-6.9.11-60

5. Edit the policy.xml file to allow PDF to PNG conversion.

    nano config/policy.xml

   I copy-pasted the following content but you can modify it as needed.

    <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE policymap [ <!ELEMENT policymap (policy)+> <!ELEMENT policy (#PCDATA)> <!ATTLIST policy domain (delegate|coder|filter|path|resource) #IMPLIED> <!ATTLIST policy name CDATA #IMPLIED> <!ATTLIST policy rights CDATA #IMPLIED> <!ATTLIST policy pattern CDATA #IMPLIED> <!ATTLIST policy value CDATA #IMPLIED> ]> <!-- Configure ImageMagick policies. Domains include system, delegate, coder, filter, path, or resource. Rights include none, read, write, and execute. Use | to combine them, for example: "read | write" to permit read from, or write to, a path. Use a glob expression as a pattern. Suppose we do not want users to process MPEG video images: <policy domain="delegate" rights="none" pattern="mpeg:decode" /> Here we do not want users reading images from HTTP: <policy domain="coder" rights="none" pattern="HTTP" /> Lets prevent users from executing any image filters: <policy domain="filter" rights="none" pattern="*" /> The /repository file system is restricted to read only. We use a glob expression to match all paths that start with /repository: <policy domain="path" rights="read" pattern="/repository/*" /> Let's prevent possible exploits by removing the right to use indirect reads. <policy domain="path" rights="none" pattern="@*" /> Any large image is cached to disk rather than memory: <policy domain="resource" name="area" value="1GB"/> Define arguments for the memory, map, area, width, height, and disk resources with SI prefixes (.eg 100MB). In addition, resource policies are maximums for each instance of ImageMagick (eg policy memory limit 1GB, -limit 2GB exceeds policy maximum so memory limit is 1GB). --> <policymap> <!-- <policy domain="resource" name="temporary-path" value="/tmp"/> --> <policy domain="resource" name="memory" value="256MiB"/> <policy domain="resource" name="map" value="512MiB"/> <policy domain="resource" name="width" value="16KP"/> <policy domain="resource" name="height" value="16KP"/> <policy domain="resource" name="area" value="128MB"/> <policy domain="resource" name="disk" value="1GiB"/> <!-- <policy domain="resource" name="file" value="768"/> --> <!-- <policy domain="resource" name="thread" value="4"/> --> <!-- <policy domain="resource" name="throttle" value="0"/> --> <!-- <policy domain="resource" name="time" value="3600"/> --> <!-- <policy domain="system" name="precision" value="6"/> --> <!-- not needed due to the need to use explicitly by mvg: --> <!-- <policy domain="delegate" rights="none" pattern="MVG" /> --> <!-- use curl --> <policy domain="delegate" rights="none" pattern="URL" /> <policy domain="delegate" rights="none" pattern="HTTPS" /> <policy domain="delegate" rights="none" pattern="HTTP" /> <!-- in order to avoid to get image with password text --> <policy domain="path" rights="none" pattern="@*"/> <policy domain="cache" name="shared-secret" value="passphrase" stealth="true"/> <!-- disable ghostscript format types --> <policy domain="coder" rights="none" pattern="PS" /> <policy domain="coder" rights="none" pattern="EPI" /> <policy domain="coder" rights="read|write" pattern="PDF" /> <policy domain="coder" rights="none" pattern="XPS" /> <policy domain="coder" rights="read|write" pattern="LABEL" /> </policymap>

6. Configure and install ImageMagick.

    ./configure --prefix=/var/task/imagemagick --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared=no --enable-static=yes --with-modules --with-perl=no --with-x=no --with-gslib=no --with-lcms --without-rsvg --with-xml --without-dps --disable-hdri --with-quantum-depth=8 --disable-openmp make sudo make install

7. Copy the required .so files.

    mkdir lib cd /usr/lib64/ cp -L libbz2.so.1 libexpat.so.1 libfontconfig.so.1 libfreetype.so.6 libgs.so.9 libjbig.so.2.0 libjpeg.so.62 liblcms2.so.2 liblzma.so.5 libpng15.so.15 libtiff.so.5 libxml2.so.2 libMagickCore-6.Q16.so.6 libMagickWand-6.Q16.so.6 libXext.so.6 libXt.so.6 libltdl.so.7 libSM.so.6 libICE.so.6 libX11.so.6 libgomp.so.1 libuuid.so.1 libxcb.so.1 libXau.so.6 libMagickCore-6.Q8.so.6 libMagickWand-6.Q8.so.6 libm.so.6 libz.so.1 libjasper.so.1 /home/ec2-user/lib/ cp -r ImageMagick-6.9.10/ ImageMagick-6.9.11/ /home/ec2-user/lib/ cd /home/ec2-user tar zcf lib.tar.gz lib/

   Copy the lib.tar.gz file from the server to your local machine.
8. Copy the required binary files.

    cd /var/task/imagemagick sudo tar zcf bin.tar.gz bin/ cp bin.tar.gz /home/ec2-user/bin.tar.gz

   Copy the bin.tar.gz file from the server to your local machine.
9. Copy the XML files required by ImageMagick.

    cd /etc/ sudo tar zcf etc.tar.gz ImageMagick-6/ cp etc.tar.gz /home/ec2-user/etc.tar.gz

   Copy the etc.tar.gz file from the server to your local machine.
10. Close the SSH session.
11. On your local machine, extract the contents of the 3 *.tar.gz files.
12. Download ghostscript from https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs9533/ghostscript-9.53.3-linux-x86_64.tgz and extract the ghostscript binary into the bin/ folder and rename it to gs . Run chmod +x bin/gs to make it executable.
13. Compress the 3 - lib , bin and etc - folders into a ZIP file. The tree structure of the ZIP file would look like

    file.zip/ |-- bin | |-- convert | |-- ... | `-- gs |-- etc | `-- ImageMagick-6 | |-- coder.xml | |-- ... | `-- type.xml `-- lib |-- ImageMagick-6.9.10 | |-- config-Q16 | | `-- configure.xml | `-- modules-Q16 | |-- coders | | |-- aai.la | | |-- ... | | `-- yuv.so | `-- filters | |-- analyze.la | `-- analyze.so |-- ImageMagick-6.9.11 | |-- config-Q8 | | `-- configure.xml | `-- modules-Q8 | |-- coders | | |-- aai.la | | |-- ... | | `-- yuv.so | `-- filters | |-- analyze.la | `-- analyze.so |-- libICE.so.6 |-- ... `-- libz.so.1

    I have used ... wherever the folder contained more than 2 files to denote that there are more files present.
14. Create a Python 3.8 runtime compatible layer on AWS Lambda and use the ZIP created in step 13.
15. Add the layer to your AWS Lambda function.
16. Update the environment variables so that wand can find ImageMagick.

     import os os.environ["PATH"] = f"/opt/bin:{os.environ['PATH']}" os.environ["LD_LIBRARY_PATH"] = f"/opt/lib:{os.environ['LD_LIBRARY_PATH']}" os.environ["MAGICK_HOME"] = "/opt/" os.environ["WAND_MAGICK_LIBRARY_SUFFIX"] = "-6.Q8" os.environ["MAGICK_CONFIGURE_PATH"] = "/opt/etc/ImageMagick-6/" os.environ["MAGICK_CODER_MODULE_PATH"] = "/opt/lib/ImageMagick-6.9.11/modules-Q8/coders/"

Note: If the size of the uncompressed ZIP file is too large and you reach AWS Lambda size limits, remove the binaries that you don't need from the bin/ folder. In my case, I only kept Magick-config , MagickCore-config , MagickWand-config , Wand-config , convert and gs and removed others.