fix(ci): use BuildKit secrets instead of build-arg for GITHUB_TOKEN#327
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fix(ci): use BuildKit secrets instead of build-arg for GITHUB_TOKEN#327
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Build arguments persist in Docker image layer metadata and can be extracted with docker history or docker inspect. Switch to --mount=type=secret so the token is only available during the RUN step and never written to any image layer.
johntmyers
approved these changes
Mar 15, 2026
drew
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Mar 16, 2026
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Summary
MISE_GITHUB_TOKENwas passed via--build-argin the CI image build, which persists the value in Docker image layer metadata (extractable viadocker history/docker inspect)--mount=type=secretso the token is only available as a tmpfs file during theRUNstep and is never written to any image layerChanges
.github/workflows/ci-image.yml— replaced--build-arg MISE_GITHUB_TOKEN=...with--secret id=MISE_GITHUB_TOKEN,env=MISE_GITHUB_TOKEN; token is set as a step-levelenvvardeploy/docker/Dockerfile.ci— removedARG MISE_GITHUB_TOKEN; added--mount=type=secret,id=MISE_GITHUB_TOKENto theRUNinstruction that callsmise installTesting
# syntax=docker/dockerfile:1.4(BuildKit enabled), so--mount=type=secretis fully supported2>/dev/null || truefallback ensures local builds without the secret still workmainafter merge