
Markus Thömmes contributed to several Chainguard repositories, focusing on infrastructure automation and reliability. He enhanced the terraform-provider-chainguard by implementing advanced data source features, such as multi-repository queries and improved debugging, using Go and Terraform. In chainguard-dev/terraform-infra-common, he strengthened error handling for cloud event ingestion by introducing robust retry logic and safe file deletion, reducing state loss risks. Markus also stabilized build and test workflows in chainguard-dev/melange by restoring apkofs.DirFS, ensuring CI reliability. His work on release automation and attestation integrity in chainguard-images/images and terraform-provider-cosign demonstrated depth in CI/CD, DevOps, and infrastructure as code.

September 2025: Delivered two changes with direct business value across Chainguard repos that boost release velocity and attestation integrity. Implemented Active Tag Publishing in the chainguard-images/images release workflow with a new make target for enabling active tag updates and an override file added to gitignore to support dynamic tag publishing during releases. Fixed a critical bug in chainguard-dev/terraform-provider-cosign by changing the default conflict resolution to SKIPSAME for both attest and sign, ensuring attestations are replaced rather than appended and preventing incorrect attestations. Commit references map to key changes: 60e9477791fdd9634f1ecc7157b4271e10d6ec63 (Enable active_tags publishing (#3015)) and dd0d7a8fe6a4b5444e11705233410d7f7ffce31d (Change default conflict mode to "SKIPSAME" (#393)).
September 2025: Delivered two changes with direct business value across Chainguard repos that boost release velocity and attestation integrity. Implemented Active Tag Publishing in the chainguard-images/images release workflow with a new make target for enabling active tag updates and an override file added to gitignore to support dynamic tag publishing during releases. Fixed a critical bug in chainguard-dev/terraform-provider-cosign by changing the default conflict resolution to SKIPSAME for both attest and sign, ensuring attestations are replaced rather than appended and preventing incorrect attestations. Commit references map to key changes: 60e9477791fdd9634f1ecc7157b4271e10d6ec63 (Enable active_tags publishing (#3015)) and dd0d7a8fe6a4b5444e11705233410d7f7ffce31d (Change default conflict mode to "SKIPSAME" (#393)).
In August 2025, delivered significant data-source enhancements for the Chainguard Terraform provider, improving image repository queries, debugging, and multi-repo access. Implemented active_tags plumbing in image_repo data source, added debugging InputParams, introduced aliases for chainguard_image_repo, and launched chainguard_image_repos data source with optional filters. Updated docs and usage examples, improving developer experience and reducing toil for operators.
In August 2025, delivered significant data-source enhancements for the Chainguard Terraform provider, improving image repository queries, debugging, and multi-repo access. Implemented active_tags plumbing in image_repo data source, added debugging InputParams, introduced aliases for chainguard_image_repo, and launched chainguard_image_repos data source with optional filters. Updated docs and usage examples, improving developer experience and reducing toil for operators.
2025-07 monthly summary: Reinstated apkofs.DirFS across melange build, tests, license checks, and linting to restore stability after reverting a previous change to os.DirFS. This stabilized CI, fixed build/test failures, and preserved tooling compatibility, enabling reliable shipping.
2025-07 monthly summary: Reinstated apkofs.DirFS across melange build, tests, license checks, and linting to restore stability after reverting a previous change to os.DirFS. This stabilized CI, fixed build/test failures, and preserved tooling compatibility, enabling reliable shipping.
June 2025: Reliability-focused improvements for Cloud Events ingestion in chainguard-dev/terraform-infra-common. Implemented a robust retry across the full upload lifecycle and adjusted deletion semantics to occur only after a successful close, reducing risk of state loss and orphaned files.
June 2025: Reliability-focused improvements for Cloud Events ingestion in chainguard-dev/terraform-infra-common. Implemented a robust retry across the full upload lifecycle and adjusted deletion semantics to occur only after a successful close, reducing risk of state loss and orphaned files.
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