Oracle on Alpine linux

I am trying to install OCI8 extension on my Alpine Linux Docker environment. Although there are several places saying it won't work, there are some which say it actually does. I have a 3.4 version and for corporate reasons it is staying like that for now.

I have done this within my Docker conf:

# Install Oracle Client and build OCI8 (Oracel Command Interface 8 - PHP extension)
USER root
ENV LD_LIBRARY_PATH=/usr/local/instantclient
ENV ORACLE_HOME=/usr/local/instantclient

RUN apk update && apk upgrade
RUN apk add musl-dev libaio autoconf && apk add --update make

## Unzip Instant Client v12
RUN pecl channel-update pecl.php.net
COPY instantclient_12_2.zip /var/www/html/instantclient_12_2.zip
RUN unzip -d /usr/local/ /var/www/html/instantclient_12_2.zip
RUN ln -s /usr/local/instantclient_12_2 /${ORACLE_HOME} && \
    ln -s /${ORACLE_HOME}/libclntsh.so.* /${ORACLE_HOME}/libclntsh.so && \
    ln -s /${ORACLE_HOME}/libocci.so.* /${ORACLE_HOME}/libocci.so && \
    ln -s /${ORACLE_HOME}/lib* /usr/lib && \
    ln -s /${ORACLE_HOME}/sqlplus /usr/bin/sqlplus &&\
    ln -s /usr/lib/libnsl.so.2.0.0  /usr/lib/libnsl.so.1

RUN apk add gcc; exit 0 # This has a history of failing sometimes

RUN echo "instantclient,/usr/local/instantclient" | pecl install oci8 &&\
    echo 'extension=oci8.so' > /usr/local/etc/php/conf.d/30-oci8.ini &&\
    rm -rf /tmp/*.zip /var/cache/apk/* /tmp/pear/

Now the build passes, and it looks okay, however when I do a php -v I am getting the following:

PHP Warning: PHP Startup: Unable to load dynamic library '/usr/local/lib/php/extensions/no-debug-non-zts-20160303/oci8.so' - Error loading shared library libnsl.so.1: No such file or directory (needed by /usr/local/instantclient/libclntsh.so.12.1) in Unknown on line 0

PHP version is 7.1.12.

What I've tried is doing apk add libnsl but this returns me this error:

ERROR: unsatisfiable constraints: so:libtirpc.so.3 (missing):

So I tried also adding apk add libtirpc-dev (the 'plain' libtirpc isn't available for my version or something), but that changed nothing.

Any clues?

I'd recommend using an operating system supported by Oracle, thus avoiding the headache of hacking Alpine and the uncertainty that it won't fall over at a critical time. And thus giving you some confidence your business won't be negatively impacted. Try https://github.com/oracle/docker-images/tree/master/OracleInstantClient

Other comments

Don't set ORACLE_HOME when using Instant Client. That variable is for full software installs.
Use ldconfig to set the system library path, see the Instant Client installation instructions e.g. here.
Use Instant Client 18.3, which can connect to the same DB versions that 12.2 can. (18.3 is really the renamed 12.2.0.2 in the new versioning system)
Using Oracle Linux Docker images has the advantage that it will download and install the 18.3 Instant Client without you having to manually do the download.

See this blog for info about the 'slim' Oracle Linux container it uses.