[Fixes #12939] Add rootless support for geonode, cited on GNIP 101 (#12769)

[giohappy]

Original contribution by @cmotadev in #12940

Geonode Docker, now rootless!!!

Objectives

• Make geonode (django/celery) to run rootless
• Apply some Dockerfile best practices, to reduce image size and number of layers
• Evict to make deeper modifications, like change libraries (except the use of curl and wget - in this case we removed wget and changed to curl)

Summary of modifications

General

• Add minimal Dockerfile labels
• Grouped apt-get commands in one RUN
• All writable files and dirctories were granted to root group (docker engine and kubernetes add container user to root group)
• No file or directories are created in runtime. if the container needs to write files, a directory are created on build time and receive chmod g=u, if the container need to create files in a system directory, the file are touched and chmoded in build time
• preserved legacy operations like sourcing .bashrc and .override_env from $HOME dir. In case of .bashrc, the entrypoint script checks if the running user has entry on /etc/passwd. if not, copy a .bashrc template from skel dir.
• created a function to parse bool entries

Specific

• Add Environment variable to set container user ID: GEONODE_USER (default 0 - root)
• Point django, celery and invoke logs to /var/log/geonode
• Tag all images on docekr-compose-dev.yml as "dev"
• Sanitize ENV and ARGs
• Removed "service cron restart" -> We can schedule tasks on genode using external cron (calling docker or docker-machine) or use a CronJob on kubernetes based systems (rancher, openshift, minikube...)

Next steps:

• Make similar modifications proposed by this PR and apply to geonode-project repo
• Apply docker best practices to geonode base image (further work)

Post Scriptum

(PS1) Geonode Volumes: If run geonode as uid 0 (root), then stop, change to unprivileged user, and start, geonode will crash due permission issues. There is two things to do: 1) Remove all volumes before change UID and start or 2) mount all volumes in a dummy container and grant write privileges to root group.

(PS2) Setting GEONODE_UID=0, geonode will run as root, like all other versions.

Documentation on rootless best practices

• https://developers.redhat.com/articles/2021/11/11/best-practices-building-images-pass-red-hat-container-certification#best_practice__3__set_group_ownership_and_file_permissions
• https://sysdig.com/learn-cloud-native/dockerfile-best-practices/

Checklist

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• There is a ticket in https://github.com/GeoNode/geonode/issues describing the issue/improvement/feature (a notable exemption is, changes not visible to end-users)
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[mattiagiupponi]

this will not be removed by the other PR for getting rid of the geoserver_data?

[cmotadev]

yes, when no longer needed

[mattiagiupponi]

Made the following test:

1. build the images for nginx, geoserver and geoserver_data from geonode-docker repo
2. set in the .env file the GEONODE_UID as 1000 since is my local user ID
   
3. update the docker-compose file to re-enable the entrypoint.sh file, otherwise Django and celery were not running
4. update the docker-compose file to use the root_less images generated at point 1
   
5. run docker-compose file as my user (not root)
   
6. Geonode is still running as root

Did i miss some step? @cmotadev @giohappy ?

[mattiagiupponi]

ok, with @giohappy we made the following two changes:

1. re-comment the entrypoint.sh in the docker-compose file
2. the entrypoint in the Dockerfile should be updated as the following: ENTRYPOINT ["/usr/src/geonode/entrypoint.sh"] by using the absolute path of the entrypoint. In this way the user is used instead of root: