Files for deployment of OCR-D processing-server

What is this?

briefly

Start OCR-D Processing-Server together with the OCR-D Webapi in a VM

Summary of what is done to run the Processing-Server

• Processing-Server and Webapi run in docker on the VM
• Workers are started on the VM
• Workers are installed in a venv
• Traefik to route to either the Processing-Server or Webapi (for workflows/workspaces management)

Details of deployment

1. create venv on VM with script ocrd-venv.sh. The needed processors are installed to this venv. venv is added to PATH with ~/.profile:

if [ -d '$HOME/venv-ocrd/bin' ]; then
  PATH=$HOME/venv-ocrd/bin:$PATH
fi

2. create ssh-key for Procesing-Server to ssh into the VM (its own host)

• the pub-key is added to ~/.ssh/authorized keys and the private key will be volume-mounted to the Processing-Server Docker Container

3. clone Webapi-Repo

• https://github.com/OCR-D/ocrd-webapi-implementation
• Reason: Webapi-container will be build from this cloned repo

4. Create Volume folder for workspaces:

• /tmp/ocrd-webapi-data
• owner is normal user (uid 1000)
• folder must be created before webapi-container startup, otherwise it will be owned by root
• must be identically for what is used in the webapi: OCRD_WEBAPI_BASE_DIR and the volume mount of /tmp/ocrd-webapi-data:/tmp/ocrd-webapi-data. Otherwise workspace_id resolving will not work

5. upload processing-server config:

• must be volume mounted to the processing-server

6. start docker-compose.yml in vm

• currently username and password are commented in the docker-compose file. They must be set to make uploading possible

Ansible

• I use the ansible-playbook to set up the VM
• the repos structure currently is based on my needs to work together with my other ansible stuff I use for other projects.

Installation and setup for/of ansible

• I forgot how I installed ansible, but that should be simple
• Ansible needs to know how to login to the servers. There is a default way to provide this info (hosts-file in /etc/ansible). But I wanted to keep the hosts here so I use ansible.cfg to set where to look for the hosts
• So it is neccessary to copy ansible.cfg.example to ansible.cfg and set inventory to the folder of this repo.
  • info regarding ansible.cfg detection: https://docs.ansible.com/ansible/latest/reference_appendices/config.html
    • first it checks env-var, then current dir, then home then /etc/ansible/ansible.cfg
• Hosts file must be copied as well: cp hosts.example hosts and the path to the ssh-key must be set

Usage:

• ansible-playbook p_install_processing_server.yml

further Infos:

• In ansible there are roles and tasks. For this script I only use tasks because of interference with my other ansible playbooks/setup
• I have a ansible-script to to a basic cloud-server setup (I use that for all my vms): install some stuff like fzf and ripgrep, disable password login, vimrc, docker-mtu etc. But this is not included here, this playbook is only about what is specific for ocrd-webapi/processing-server

Examples / Test

• the examples folder contains example workflows and my script which I use to test a running installation

usage

• create config.yaml from template config.example.yaml. Fill variables especially HOST, USER and PASSWORD which are required for running a workflow
• ./ocrd-ps-test-tool.py run-workflow -e PAGE wf_halle_example.nf