Missing perl command in Perl image - docker

Question

I'm sure this is an incredibly simple fix. I tried to build Docker image with Perl in it (plus some Perl) modules. However, when I go to run this, it says there is no /bin/perl. The question is:
Why did the Perl Docker Image not have Perl in it?
My Dockerfile below:
FROM perl:5.20
ENV PERL_MM_USE_DEFAULT 1
RUN cpan install Net::SSL inc:latest
RUN mkdir /ssc
COPY /ssc /ssc
RUN mkdir /tmp/ssc-bin-files;cp /ssc/bin/*.sh /tmp/ssc-bin-files;chmod a+rx /tmp/ssc-bin-files/*;cp /tmp/ssc-bin-files/* /ssc/bin
RUN chmod a+rx /ssc/bin/*.sh
ENTRYPOINT ["/ssc/bin/put-and-submit.sh"]
Jenkins Pipeline snippet:
stage('Build, Tag and Push SSC Dockerfile'){
tagAsTest = "${IMAGE_NAME}:test"
REPO = "chq-ic2e-sprint-images-docker-local"
println "Docker App Build"
docker.build(tagAsTest,"-f Dockerfile .")
sh 'docker image ls | grep rules-client'
}
stage('Set image tag to :approved'){
hasReachedDockerComposeUp=false;
REPO = "chq-ic2e-sprint-images-docker-local"
sh "docker tag ${IMAGE_NAME}:test ${IMAGE_NAME}:approved"
buildInfo = rtDocker.push("${IMAGE_NAME}:approved", REPO , buildInfo)
server.publishBuildInfo buildInfo
}
The Jenkins log below:
[Pipeline] sh
+ docker build -t chq-ic2e-sprint-images-docker-local.artifactory.swg-devops.com/ssc-cost-file-processor:test -f Dockerfile .
Sending build context to Docker daemon 39.42kB
Step 1/8 : FROM perl:5.20
---> bbe5a82c1dbe
Step 2/8 : ENV PERL_MM_USE_DEFAULT 1
---> Using cache
---> ca2769a89ab8
Step 3/8 : RUN cpan install Net::SSL inc:latest
---> Using cache
---> 1e53f0573131
Step 4/8 : RUN mkdir /ssc
---> Using cache
---> a324effec8ce
Step 5/8 : COPY /ssc /ssc
---> d40bf34f8565
Step 6/8 : RUN mkdir /tmp/ssc-bin-files;cp /ssc/bin/*.sh /tmp/ssc-bin-files;chmod a+rx /tmp/ssc-bin-files/*;cp /tmp/ssc-bin-files/* /ssc/bin
---> Running in 02386f41174f
Removing intermediate container 02386f41174f
---> 4767a8e6f23a
Step 7/8 : RUN chmod a+rx /ssc/bin/*.sh
---> Running in 07646aa96048
Removing intermediate container 07646aa96048
---> f070fcd8a9e9
Step 8/8 : ENTRYPOINT ["/ssc/bin/put-and-submit.sh"]
---> Running in e6bab12f8f40
Removing intermediate container e6bab12f8f40
---> 1422df9d957b
Successfully built 1422df9d957b
Successfully tagged chq-ic2e-sprint-images-docker-local.artifactory.swg-devops.com/ssc-cost-file-processor:test
[Pipeline] sh
+ docker image ls
+ grep rules-client
chq-ic2e-sprint-images-docker-local.artifactory.swg-devops.com/rules-client approved da334d1d8fae 2 days ago 22.5MB
chq-ic2e-sprint-images-docker-local.artifactory.swg-devops.com/rules-client test da334d1d8fae 2 days ago 22.5MB
Script is being run via pipeline like this:
stage('Run image'){
sh '''
docker run -i -v \
--mount type=bind,source="$(pwd)/host-dirs,target=/host-dirs" \
chq-ic2e-sprint-images-docker-local.artifactory.swg-devops.com/ssc-cost-file-processor:approved
sh
'''
}
or from terminal like this:
#!/bin/bash
docker run -it \
--mount type=bind,source="$(pwd)/host-dirs,target=/host-dirs" \
chq-ic2e-sprint-images-docker-local.artifactory.swg-devops.com/ssc-cost-file-processor:approved sh

Answer 1

The perl binary is probably in /usr/local/bin/perl. You can check that in a shell in the running container.
host> docker exec -it your_container bash
container> which perl
/usr/local/bin/perl
container> exit

Answer 2

It sure has perl version 5.20 in it. I'm just curious about the entrypoint script in your dockerfile. You're running a shell script by default when the container is started. What the script starts or runs? If you want to run perl without entering the container, use --entrypoint=perl with your docker run command.
docker run --rm --name perl perl:5.20 perl --version
### Output
This is perl 5, version 20, subversion 3 (v5.20.3) built for x86_64-linux
(with 1 registered patch, see perl -V for more detail)
Copyright 1987-2015, Larry Wall
Perl may be copied only under the terms of either the Artistic License or the
GNU General Public License, which may be found in the Perl 5 source kit.
Complete documentation for Perl, including FAQ lists, should be found on
this system using "man perl" or "perldoc perl". If you have access to the
Internet, point your browser at http://www.perl.org/, the Perl Home Page.
###