Consider installing tomcat native libraries or provide variant that does.

[dougborg]

We are currently doing this in our tomcat container ((https://registry.hub.docker.com/u/readytalk/tomcat-native/dockerfile/), and I think it should actually be part of the official one :

ENV DEBIAN_FRONTEND noninteractive
ENV LD_LIBRARY_PATH ${LD_LIBRARY_PATH}:/usr/lib/x86_64-linux-gnu/

RUN apt-get update
RUN apt-get install -y libtcnative-1

More information on the tomcat native libraries here:
http://tomcat.apache.org/tomcat-8.0-doc/apr.html

From the docs:

Tomcat can use the Apache Portable Runtime to provide superior scalability, performance, and better integration with native server technologies. The Apache Portable Runtime is a highly portable library that is at the heart of Apache HTTP Server 2.x. APR has many uses, including access to advanced IO functionality (such as sendfile, epoll and OpenSSL), OS level functionality (random number generation, system status, etc), and native process handling (shared memory, NT pipes and Unix sockets).

These features allows making Tomcat a general purpose webserver, will enable much better integration with other native web technologies, and overall make Java much more viable as a full fledged webserver platform rather than simply a backend focused technology.

I'd be happy to open a pull request if this is something people are interested in.

[yosifkit]

This seems fine to me, but I am just the maintainer and not a user. Any users have an opinion here? Would a separate tag be better (there are already quite a few of them) or just include it always?

What is the size difference if we add this just before the RUN gpg --keyserver... lines?

RUN apt-get update \
    && apt-get install -y libtcnative-1 \
    && rm -rf /var/lib/apt/lists/*

[tianon]

Wouldn't we need to pull libtcnative from upstream instead of from
packages, like how we pull tomcat?

[alexsantos]

👍

BTW, installing from packages I get this INFO:

INFO: An older version 1.1.32 of the APR based Apache Tomcat Native library is installed, while Tomcat recommends a minimum version of 1.1.33

[md5]

Based on @alexsantos's comment, I think the answer to @tianon's question about whether to pull from upstream instead from packages is "Yes". Looks like 1.1.33 is available in Debian Sid, but not in any of the other suites.

[md5]

Regarding @yosifkit's comments, I don't think that including libtcnative necessitates additional tags. APR support should be built into all versions of the tomcat image.

[yosifkit]

Cool, anyone up to adding an up-to-date libtcnative?

[md5]

I don't have time at the moment, but it looks pretty easy. The build instructions are here: https://svn.apache.org/repos/asf/tomcat/native/branches/1.1.x/native/BUILDING

The source package and GPG signature can be downloaded via: https://tomcat.apache.org/download-native.cgi

[md5]

I spent a little time tonight getting libtcnative to build from source. The result is here: master...appropriate:libtcnative

I didn't bother to update the update.sh script yet because I didn't look into how to determine the right version of libtcnative required for a particular version of Tomcat.

You may also notice that I had to install the full JDK in order to build libtcnative... It gets removed in the same RUN statement, so the resulting layer is about 4 megabytes (it could be smaller by half if I removed the libtcnative*.a file that gets installed).

[md5]

I just noticed this in the docs:

The wrapper library sources are located in the Tomcat binary bundle, in the bin/tomcat-native.tar.gz archive.

That should mean that the approach I took in my demonstration branch of downloading tomcat-native-$TCNATIVE_VERSION-src.tar.gz is unnecessary. I don't have time to test right now, but it seems worth investigating.

[md5]

OK, I lied. I did at least have time to confirm that the sources are already there:

$ docker run --rm tomcat find /usr/local/tomcat -name '*.tar.gz'
/usr/local/tomcat/bin/commons-daemon-native.tar.gz
/usr/local/tomcat/bin/tomcat-native.tar.gz

[ismaello]

Just after install tomcat7:
#No install libnative via apt-get
RUN apt-get update &&
apt-get install -yq build-essential openssl libssl-dev curl

RUN cd /tmp
&& curl -fSL "http://www.us.apache.org/dist//apr/apr-1.5.2.tar.gz" -O
&& tar xvzf apr-1.5.2.tar.gz && cd apr-1.5.2
&& ./configure --prefix=/usr/local/apr && make && make install

RUN cd /tmp
&& curl -fSL "http://www.us.apache.org/dist/tomcat/tomcat-connectors/native/1.1.33/source/tomcat-native-1.1.33-src.tar.gz" -O
&& tar xvzf tomcat-native-1.1.33-src.tar.gz && cd tomcat-native-1.1.33-src/jni/native
&& ./configure --with-apr=/usr/local/apr && make && make install

ENV LD_LIBRARY_PATH /usr/local/apr/lib:$LD_LIBRARY_PATH

[md5]

Thanks @ismaello!

These steps look correct, but I also think installing libapr1 from the Debian package would be fine. In addition, I believe it's prudent to use the tomcat-native source that's bundled with the version of Tomcat used in the image in order to ensure that the correct version is used.

Any chance you'd want to create a PR based on your instructions, but using apt-get to install libapr1 and using the tomcat-native tarball at /usr/local/tomcat/bin/tomcat-native.tar.gz? You'll need to install and remove libapr-dev as well for building the tomcat-native source.