* Add systemd_exporter Ansible role and Prometheus scrape config
- Create systemd_exporter role (download binary, create user, deploy service)
- Add scrape job for london-b:9558 and copenhagen-a:9558
- Add systemd_exporter_hosts inventory group
- Add stage 3b to deploy.yml
- Map role to deploy-on-merge scope
Closes PESO-120
* Fix line length lint violations in systemd_exporter tasks
* Fix var-naming lint: use systemd_exporter_ prefix for role variables
Instead of deploying to the entire fleet on every merge, detect which
files changed and limit ansible-playbook to only affected hosts.
Maps ansible roles, services, and host_vars to their target hosts.
Falls back to full fleet deploy for unmapped paths or changes to
shared infrastructure (common role, deploy.yml, inventory).
Closes PESO-108
Both deploy-on-merge.yml and deploy.yml install ansible via pip but
never install the required Galaxy collections (community.docker,
community.general, ansible.posix) from ansible/requirements.yml.
This works by accident because the pip ansible package bundles some
collections, but it's fragile — a pip upgrade or runner image change
could break deploys silently.
Fixes PESO-110
* Add Docker official apt repo to docker role
The docker role was installing docker-compose-plugin which is only
available from Docker's official apt repository. helsinki-a had it
configured manually, but london-b and copenhagen-a did not, causing
deploy failures.
Now the role:
- Adds Docker's GPG key and apt repo (handles both Debian and Ubuntu)
- Installs docker-ce, docker-ce-cli, containerd.io, docker-compose-plugin
- Removes conflicting stock packages (docker.io, docker-compose)
* fix: resolve yamllint violations in docker role
- Remove standalone comment blocks that caused indentation errors
- Collapse multiline repo string to single line
- Ensure document start marker is present
* fix: keep all lines under 160 chars for yamllint
Use set_fact to build the Docker repo line in parts instead of
one long inline string.
* fix: resolve yamllint errors in london-b host_vars and promtail config
- Remove trailing blank line in inventory/host_vars/london-b.yml
- Add missing document start marker to promtail config
- Fix indentation in promtail scrape_configs (indent list items under key)
* Remove ansible-lint on push, keep PR-only
Lint already runs on pull_request — no need to double up on push to main.