Skip to content

build(image): drop the Go build cache from the container image #376

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
sunib merged 1 commit into from
Sep 18, 2026
Merged

build(image): drop the Go build cache from the container image #376

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 18 additions & 4 deletions .devcontainer/Dockerfile
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -276,19 +276,29 @@ RUN chgrp -R godev /go && \

# Install Go tools used by the project (using @version doesn't need go.mod)
# These run AFTER permissions are set to ensure proper group ownership
#
# `go clean -cache` drops the Go *build* cache each `go install` leaves behind.
# Only the module cache (/go/pkg/mod) is worth shipping: it is stable, highly
# reusable, and Go never trims it. A build cache cannot survive in an image,
# because a layer freezes every entry's mtime and Go garbage-collects entries
# by mtime -- so once this layer is older than trimLimit (5 days) the first
# `go` build in any container deletes ~90% of it regardless. Cleaning in the
# same layer keeps those ~400MB out of the image instead of merely hiding them.
RUN go install sigs.k8s.io/controller-tools/cmd/controller-gen@v0.22.0 \
&& go install github.com/onsi/ginkgo/v2/ginkgo@v2.32.1 \
&& go install sigs.k8s.io/controller-runtime/tools/setup-envtest@v0.25.0 \
&& go install golang.org/x/tools/cmd/goimports@v0.49.0 \
&& go install github.com/boyter/scc/v4@v4.0.0
&& go install github.com/boyter/scc/v4@v4.0.0 \
&& go clean -cache

# Initialize golangci-lint cache by running it once on an empty directory
# This downloads linter dependencies without needing source code
RUN mkdir -p /tmp/golangci-init && cd /tmp/golangci-init \
&& go mod init example.com/init \
&& printf 'package main\n\nfunc main() {}\n' > main.go \
&& golangci-lint run --timeout=5m || true \
&& cd / && rm -rf /tmp/golangci-init
&& cd / && rm -rf /tmp/golangci-init \
&& go clean -cache

# Pre-download Go modules for caching - placed AFTER tool installation
# This layer will be cached and only rebuilt when go.mod/go.sum changes
Expand Down Expand Up @@ -390,15 +400,19 @@ RUN arch="$(dpkg --print-architecture)" && \

# Install Delve debugger for Go debugging in VSCode
# ACLs from CI stage should be preserved, so no need to re-apply
RUN go install github.com/go-delve/delve/cmd/dlv@${DLV_VERSION}
# Build cache cleaned for the same reason as the ci stage above; the devcontainer
# works as `vscode`, so root's build cache here is only dead image weight.
RUN go install github.com/go-delve/delve/cmd/dlv@${DLV_VERSION} \
&& go clean -cache

# Install VSCode Go extension tools (gopls and staticcheck). Both are editor-only:
# gopls is the language server, and this standalone staticcheck powers the editor's
# live (as-you-type) diagnostics. Neither is a lint step -- `task lint` already runs
# staticcheck's analyzers via golangci-lint's bundled staticcheck linter (configured in
# .golangci.yml), so this binary is for the IDE, not a second lint pass.
RUN go install golang.org/x/tools/gopls@${GOPLS_VERSION} \
&& go install honnef.co/go/tools/cmd/staticcheck@${STATICCHECK_VERSION}
&& go install honnef.co/go/tools/cmd/staticcheck@${STATICCHECK_VERSION} \
&& go clean -cache

# Create vscode user for non-root development and add to godev group
RUN groupadd --gid 1000 vscode \
Expand Down
Loading