ci: free disk space before Runner Tests to avoid Docker pull failures

[MiroCillik]

Summary

The Runner Tests job runs on a Microsoft-hosted ubuntu-latest agent and pulls many large component images during the suite. That exhausts /var/lib/docker and the job fails intermittently with:

Cannot pull image '…keboola.snowflake-transformation:1.5.0':
write /var/lib/docker/tmp/GetImageBlob…: no space left on device

This is not a test failure — it's the agent running out of disk mid-run.

Fix

Add a Free disk space step at the start of the runnerTests job that reclaims the OS disk (where /var/lib/docker lives) by removing the large preinstalled toolsets the agent image ships but this repo never uses — .NET (/usr/share/dotnet), Android SDK (/usr/local/lib/android), Haskell (/opt/ghc, /usr/local/.ghcup) and CodeQL (/opt/hostedtoolcache/CodeQL) — and runs docker system prune -af. It prints df -h and a du breakdown before/after so we can see actual numbers and tune later.

Scoped to runnerTests (the job that fails). If the same wall is hit by other hosted-agent jobs (e.g. the storage-backend suites) the same step can be added there; if freeing the OS disk turns out to be insufficient, the fallback is relocating Docker's data-root to a larger mounted volume.

Unblocks CI for #805 (AJDA-3007).

Release Notes

• Justification

  • CI-only change. The Runner Tests job intermittently fails because the hosted build agent runs out of disk while pulling component images; this frees agent disk so the suite can complete. No product/runtime code is touched.

• Plans for Customer Communication

  • None. Internal CI change, no customer-facing impact.

• Impact Analysis

  • Affects only the CI pipeline (azure-pipelines.yml), the runnerTests job. The removed directories are unused preinstalled toolsets on the ephemeral agent; deletion is scoped to the agent VM for that run. No impact on tenants or runtime behavior.

• Deployment Plan

  • Merge to main; applies to subsequent pipeline runs. No deployment.

• Rollback Plan

  • Fully reversible — revert the commit.

• Post-Release Support Plan

  • None. Watch the next Runner Tests run; the before/after df -h output confirms how much space is reclaimed.

[keboola-pr-reviewer-bot]

Verdict: needs_human (risk 2/5) · profile ajda

CI/CD pipeline edit — policy mandates human review for pipeline changes regardless of size.

Concerns:

• azure-pipelines.yml: CI pipeline change (needs human per policy); adds sudo rm -rf + docker prune to runnerTests

Suggested reviewers: pr-author

[Copilot]

Pull request overview

This PR updates the Azure Pipelines CI to reduce intermittent Runner Tests failures caused by the hosted ubuntu-latest agent running out of disk space under /var/lib/docker while pulling large Docker images.

Changes:

• Add a Free disk space step at the start of the runnerTests job to remove large preinstalled toolsets (e.g., .NET, Android, GHC) and prune Docker state.
• Print df -h / before/after cleanup to make reclaimed space visible in CI logs.

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