DaCHS on Docker

Update:

Recently the Dachs-on-Docker images repository -- on DockerHub -- have been changed from chbrandt to gavodachsorganisation. The documentation is being reviewed and updated accordingly, but if/whenever you see a chbrandt/dachs, read, change it to gavodachs/dachs.

Here you'll find recipes for building and running GAVO DaCHS in Docker containers.

These files build the images available in DockerHub's gavodachs repositories.

• Quick Dachs
  1. Run it
  2. Build it
  3. Images
• Other pages:
  • versioning your resources,
  • persisting data,
  • upgrading DaCHS,
  • running dachs and postgresql individually.

Quick Dachs

DaCHS service is composed by two daemons: PostgreSQL and the Dachs server. Postgres stores the data, while Dachs-server interfaces the user (web, api) and manages the astro/planetary data accordingly. By default, Dachs provides its (api) endpoints at port 8080 on localhost.

For fine details about DaCHS, refer to the official docs: soft.g-vo.org.

Run it

If all you wanna do now is to see Dachs-on-Docker running:

[~/]$ docker run -it -p 8080:8080 --name dachs gavodachs/dachs

# some initialization output (...)

[root@10dd4547e]$ service postgresql start
Starting PostgreSQL 13 database server: main.
[root@10dd4547e]$
[root@10dd4547e]$ dachs serve debug
<date> [-] Log opened.
<date> [-] Site starting on 8080
<date> [-] Starting factory <twisted.web.server.Site object at 0x7fb33c844fd0>
Starting VO server: dachs.

Docker run will instantiate the container and hand you a bash session from inside the container. Then we start Postgres to finally start Dachs (in debug mode to have it verbose).

The /dachs.sh you will find in the container is a simple script to start/stop the servers for your convenience (eg, /dachs.sh start will do the above steps).

You go to http://localhost:8080 and you should see Dachs frontpage:

And in the terminal, lines like the following should pop out in the terminal:

<date> [-] 172.17.0.1 - - [<date>] "GET / HTTP/1.1" 200 1221 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.1.2 Safari/605.1.15"
<date> [-] 172.17.0.1 - - [<date>] "GET /static/js/jquery-gavo.js HTTP/1.1" 200 66576 "http://localhost:8080/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.1.2 Safari/605.1.15"
<date> [-] 172.17.0.1 - - [<date>] "GET /static/img/logo_medium.png HTTP/1.1" 200 48422 "http://localhost:8080/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.1.2 Safari/605.1.15"
(...)

While this terminal is being used by dachs server we can open another terminal and attach to the same container (dachs):

[~/]$ docker exec -it dachs bash
[root@10dd4547e]$
[root@10dd4547e]$ # The services running, for example:
[root@10dd4547e]$
[root@10dd4547e]$ ps ax
  PID TTY      STAT   TIME COMMAND
    1 pts/0    Ss     0:00 /bin/bash --rcfile /help.sh
   50 ?        Ss     0:00 /usr/lib/postgresql/13/bin/postgres -D /var/lib/postgresql/13/main -c config_file=/etc/postgresql/13/main/postgresql.conf
   52 ?        Ss     0:00 postgres: 13/main: checkpointer 
   53 ?        Ss     0:00 postgres: 13/main: background writer 
   54 ?        Ss     0:00 postgres: 13/main: walwriter 
   55 ?        Ss     0:00 postgres: 13/main: autovacuum launcher 
   56 ?        Ss     0:00 postgres: 13/main: stats collector 
   57 ?        Ss     0:00 postgres: 13/main: logical replication launcher 
   75 pts/0    Sl+    0:01 /usr/bin/python3 /usr/bin/dachs serve debug
   76 ?        Ss     0:00 postgres: 13/main: gavo gavo 127.0.0.1(53334) idle
   78 ?        Ss     0:00 postgres: 13/main: gavo gavo 127.0.0.1(53338) idle
  133 pts/1    Ss     0:00 bash
  139 pts/1    R+     0:00 ps ax
  [root@10dd4547e]$

Build it

Likewise, if you just want to build the latest dachs image, do:

[~/]$ cd dockerfiles
[~/dockerfiles]$ docker build -t my_dachs dachs/
(...)
=> => exporting layers
=> => writing image sha256:ddb02867...
=> => naming to docker.io/library/my_dachs

[~/dockerfiles]$ docker run --rm my_dachs /help.sh

==========================================================
This image provides dachs & postgresql bundled together,

(...)

DaCHS version: 2.5
PSQL version: 13.5
==========================================================

[~/dockerfiles]$ 

For more details on building images, go to dockerfiles/README.md

Images

The containers are built on top of Debian Bullseye image, which GAVO/DaCHS package is part of the main (and backports) repository (current Dachs version: 2.3). For the latest images we use also GAVO repositories, where updates go first (current Dachs version: 2.5).

There are three images in our context: dachs, server, postgres. Those three images are to provide two different running setup: using just one image, dachs, like we just did; Or as a pair of containers, postgres and (dachs) server, talking to each other.

The single-container setup:

• gavodachs/dachs[:tag] provides a "one-shot" solution for having Dachs running in its simple; Dachs-server and Postgres run inside the same container.

The other two images provide Dachs and Postgres in their individual containers:

• gavodachs/server[:tag] provides gavodachs-server, depends on postgres.

• gavodachs/postgres[:tag] provides PostgreSQL for use by dachs-server.

  How to run server/postgres is covered in page 'individual_containers.md'.

Tags

The tags reflect the apt repositories set up in there:

• latest,gavo: uses all repositories (Debian and Gavo)
• backports: uses all Debian repositories
• main: uses only Debian's stable/main

See etc/apt_sources.list for the actual list of repositories used (they are enabled-or-not during the building of the image, according to building arguments).

Check the documents directory (docs/) for more content.

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