Script to create Oracle XE slim images

[marcelo-ochoa]

The idea is to provide an slim version of latest Oracle XE Docker image image only with binaries and the ability to recreate a fresh Oracle instance from golden images in RMAN compressed full backup format.
Once of mainly motivation of smaller image size and faster creation time is to have a Docker image ready to be used in CI/CD pipelines which requires a fresh RDBMS for unit testing, also an slim image will reduce the network traffic between the CI/CD testing server and the private/public registry hosting the slim image.
Comparison results using this new image:
Image size: 30% of the original (8.52Gb -> 2.61Gb)
DB Creation time, 3x faster:

dbca : 8".8s (traditional way)
init-db.tar.gz : 3".5s
rman comp. : 2".59s

Docker image creation process uses multi-stage build and a modified script shared by Gerald Venzl and Jacek Gebal to cleanup non necessary stuff.
To get a golden image file either in format tar, tar.gz an RMAN directory with a setup script could be used in conjunction with oracle:18.4.0 image as:

$ docker run -ti --rm --name freshdb -v /home/setup:/opt/oracle/scripts/setup -v /run/shm:/dev/shm oracle/database:18.4.0-xe

directory /home/setup having:

$ ll /home/setup/
total 20
drwxr-xr-x 2 oracle oinstall  4096 feb 26 16:29 ./
drwxr-xr-x 8 mochoa mochoa   12288 feb 26 16:29 ../
-rwxr-xr-x 1 oracle oinstall   330 feb 26 16:29 zz-backup-full.sh*

$ cat /home/setup/zz-backup-full.sh
#!/bin/bash
su -p oracle -c "rman target /<<EOF
shutdown immediate;
startup mount;
backup as compressed backupset database format '/opt/oracle/scripts/setup/%U';
backup current controlfile format '/opt/oracle/scripts/setup/control.bks';
backup spfile format '/opt/oracle/scripts/setup/spfile.bks';
alter database open;
exit;
EOF"

once the log output shows "DATABASE IS READY TO USE!" setup directory will have a golden image DB as RMAN format which will be passed as setup directory for oracle/database:18.4.0-xe-slim image or packaged as .tar or .tar.gz file format, here the content of full backup directory:

$ ll /home/setup/
total 699436
drwxr-xr-x 2 oracle oinstall      4096 feb 26 16:53 ./
drwxr-xr-x 8 mochoa mochoa       12288 feb 26 16:29 ../
-rw-r----- 1 oracle oinstall 347537408 feb 26 16:52 01uphaqd_1_1
-rw-r----- 1 oracle oinstall 175022080 feb 26 16:52 02upharq_1_1
-rw-r----- 1 oracle oinstall 174718976 feb 26 16:53 03uphasj_1_1
-rw-r----- 1 oracle oinstall  18808832 feb 26 16:53 control.bks
-rw-r----- 1 oracle oinstall    114688 feb 26 16:53 spfile.bks
-rwxr-xr-x 1 oracle oinstall       330 feb 26 16:29 zz-backup-full.sh*

Make sure that /home/setup is owned by Oracle (54321:54321) in order to get RMAN working.
To pack RMAN content as init-db.tar.gz just use:

$ sudo tar cvfz /tmp/init-db.tar.gz control.bks spfile.bks 0*
control.bks
spfile.bks
01uphaqd_1_1
02upharq_1_1
03uphasj_1_1

PD: This PR also included Dockerfile.nfs files as example of how to use Oracle dNFS backup file-system for datafiles.

[Djelibeybi]

I notice you called this PR "Oracle XE slim image" but the actual Dockerfile is for Enterprise 18.3. Can you clarify that?

[marcelo-ochoa]

Avi:
[18.3.0|19.3.0]/Dockerfile.nfs are samples for using Oracle dNFS multi-path access to the datafiles.
https://medium.com/oracledevs/oracle-dnfs-with-docker-8a3e35c0b558
Docker slim image is mainly located at 18.4.0 directory which is XE version.
Marcelo.

[Djelibeybi]

I would suggest splitting this PR into two: one for the Oracle XE slim image and another one for dNFS support for Oracle EE 18.3/19.3.

[Djelibeybi]

I would also highly recommend creating a branch for each of these and squashing your commits for each feature prior to submitting the separated PRs.

[marcelo-ochoa]

Ready, dNFS samples in other PR soon

[Djelibeybi]

Included in #1666