I think there is som confusion of what RUN in a Dockerfile does. It executes the command during the build of the image. That would be handled by a shell provisioner in Packer.
What process gets started when you *run* the container from the resulting image is handled by ENTRYPOINT and CMD those can be set in packer with the changes 1). So to produce a image that runs systemd do: a) shell provisioner to install systemd and services b) change the ENTRYPOINT/CMD in changes to run systemd. 1) https://packer.io/docs/builders/docker.html#changes // Rickard PS. Multiprocess containers can (and should) really be questioned. On Tue, Feb 12, 2019 at 6:14 PM Vincent Rubiolo < vincent.rubi...@datameer.com> wrote: > Hi Daniel, > On 2/12/19 2:29 AM, Daniel Ortega wrote: > > We want to use our Java docker image (tagged as > *idealista/8u181-stretch-openjdk-headless > <https://hub.docker.com/r/idealista/jdk/tags>* in Docker Hub) which is > based in Debian Stretch Slim. > > This image *doesn't have systemd* (neither official image, nor our > derived image one), so this package should be installed to be used later to > configure our services. AFAIK, if you want to use systemd to manage > services, this process should be the first -> should be present in Docker > run command. But the problem is, before installation /lib/system/systemd is > not present, so the container cannot start. This could be solved using RUN > when you are using Dockerfiles, because that commands are executed in the > image "build phase". You can install systemd before and execute > /lib/system/systemd at container startup. > > As Rickard said, you can use a shell provisioner to run any command you > want (in this case the one to start systemd) once your container is up with > Packer. Another solution is to override the RUN command (as per > https://www.packer.io/docs/builders/docker.html#run_command) to specify > what you want. > > So in short I'd advise: > > 1. Start your container with Packer using the default settings. > 2. Install the packages you want (either via a shell or Ansible > provisioner), like systemd. > 3. In your shell provisioner, manually start systemd, then use it to > configure the services > > AFAIK, systemd must be running when you use commands like 'service' but it > does not need to be started when the container starts (there are ways to do > that if needed). > > On a related note, I had a similar issue with the container not starting, > because the default Packer 'docker run' command relies on /bin/bash + not > having an entrypoint set (cf > https://github.com/hashicorp/packer/issues/6920). The changes was made > but later reverted because of backward compatibility issues. You might find > the issue useful in your case tool. > > Let us know how it goes, > > Vincent > > -- > This mailing list is governed under the HashiCorp Community Guidelines - > https://www.hashicorp.com/community-guidelines.html. Behavior in > violation of those guidelines may result in your removal from this mailing > list. > > GitHub Issues: https://github.com/mitchellh/packer/issues > IRC: #packer-tool on Freenode > --- > You received this message because you are subscribed to the Google Groups > "Packer" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to packer-tool+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/packer-tool/72c11e2b-38c1-2890-8ba0-ae3da7012f40%40datameer.com > <https://groups.google.com/d/msgid/packer-tool/72c11e2b-38c1-2890-8ba0-ae3da7012f40%40datameer.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- This mailing list is governed under the HashiCorp Community Guidelines - https://www.hashicorp.com/community-guidelines.html. Behavior in violation of those guidelines may result in your removal from this mailing list. GitHub Issues: https://github.com/mitchellh/packer/issues IRC: #packer-tool on Freenode --- You received this message because you are subscribed to the Google Groups "Packer" group. To unsubscribe from this group and stop receiving emails from it, send an email to packer-tool+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/packer-tool/CALz9Rt95T1LBKUrJPYEkg_4SdqtMzxDkC_5wtDK3ohS_3m0wAw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
