This document discusses the author's early experiences with Docker six years ago. It describes how Docker helped solve an issue where a Postgres database update failed, breaking a Nuxeo installation. By using previous Postgres Docker images from the image history, the author was able to dump the old database, start a new database container, and import the dump to fix the problem. The author notes how Docker image history has provided other useful capabilities, such as investigating security issues and using outdated software versions.

1. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 1/9
DOCKERDOCKER
6th Anniversary !6th Anniversary !
My small humble use casesMy small humble use cases

2. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 2/9
2 words about me2 words about me
$ cat ~/.bash_profile
NAME="René Ribaud"
AGE=43
source ./1998.sh
PROFESSION="Unices system and storage"
"administrator , since 2003"
HISTORY="Lots (too many) infrastructure"
"implementation projects"
"Discover Linux & FLOSS between"
"1995 / 2000"
"First step in the cloud around 2011"
", pre-sales solution architect"
"2014 (Cloud, DevOps)"
"I’m an Ops !"
COMPANY="CGI 20th November 2017"
JOB="Information system architect"
"specialized around DevOps technologies"

3. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 3/9
The beginning of the storyThe beginning of the story
It starts from Yann's callIt starts from Yann's call

4. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 4/9
The battlefieldThe battlefield

5. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 5/9
Crime scene investigationCrime scene investigation
Who: Nuxeo is dead !
Murder weapon:
Postgres
Evidence: Debian update

6. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 6/9
Postgres stuckPostgres stuck
Postgres update failure
Postgres migration DB failed
But engine updated
Engine can not start with the old DB
Package downgrade looks tricky due
to dependencies
Not sure about backups... 😰

7. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 7/9
Docker to the rescue ! 🐳Docker to the rescue ! 🐳
Install Docker
Get previous Postgres image thanks
to Docker hub history
Start the old DB with Docker
Dump the DB using Docker and
pg_dump
Wipe the old DB
Restart the new engine
Import the dump
Problem fixed 🤘

8. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 8/9
Images historyImages history
Other use casesOther use cases
Get previous Rust (language 🦀)
tooling
Investigate security issues
(shellshock)
Use python3 on RHEL7 not
configured with supplemental
repository
Docker images history brings value,
it allows to play with old software
revisions with minimal system
intrusion

9. 3/27/2019 Docker 6th Anniversary !
localhost:8000/docker6anniversary/?print-pdf#/ 9/9
THANK YOUTHANK YOU
René Ribaud
<rene.ribaud@cgi.com>