| name | nic-docker-images |
| description | Docker image build system, Dockerfile structure, image variants, build scripts, and Makefile targets for NIC. Use when building container images, modifying the Dockerfile, adding new image variants, debugging image builds, or working with build scripts. |
NIC Docker Image Build System
Dockerfile Architecture
Single build/Dockerfile (~850 lines), heavily multi-stage. The BUILD_OS arg selects which base image stage is used.
nginx-files (scratch) <- Collects repo files, signing keys, scripts
|
OS-specific base stages <- One per variant (debian, alpine, ubi, *-plus, *-nap)
|
FROM ${BUILD_OS} AS common <- Runs common.sh + patch-os.sh, sets permissions
|
TARGET stages (final image) <- local, container, goreleaser, debug, download, aws, patched
Image Variants
3 OS families x 2 NGINX editions x optional NAP = ~20 variants.
| OS | OSS | Plus | Plus+WAF | Plus+WAFv5 | Plus+DoS | Plus+WAF+DoS | Plus+FIPS | Plus+WAF+FIPS | Plus+WAFv5+FIPS |
|---|
| Debian | yes | yes | yes | yes | yes | yes | - | - | - |
| Alpine | yes | yes | - | - | - | - | yes | yes | yes |
| UBI 10 | yes | yes | yes | yes | yes | yes | - | - | - |
Architecture: amd64 + arm64 for OSS and Plus. NAP variants are amd64 only.
Makefile Image Targets
All targets call docker build --platform linux/$(ARCH) --target $(TARGET) -f build/Dockerfile.
| Target | BUILD_OS | NAP_MODULES |
|---|
debian-image | debian | - |
alpine-image | alpine | - |
ubi-image | ubi | - |
debian-image-plus | debian-plus | - |
alpine-image-plus | alpine-plus | - |
alpine-image-plus-fips | alpine-plus-fips | - |
alpine-image-nap-plus-fips | alpine-plus-nap-fips | waf |
alpine-image-nap-v5-plus-fips | alpine-plus-nap-v5-fips | waf |
ubi-image-plus | ubi-10-plus | - |
debian-image-nap-plus | debian-plus-nap | waf |
debian-image-nap-v5-plus | debian-plus-nap-v5 | waf |
debian-image-dos-plus | debian-plus-nap | dos |
debian-image-nap-dos-plus | debian-plus-nap | waf,dos |
ubi-image-nap-plus | ubi-10-plus-nap | waf |
ubi-image-nap-v5-plus | ubi-10-plus-nap-v5 | waf |
ubi-image-dos-plus | ubi-10-plus-nap | dos |
ubi-image-nap-dos-plus | ubi-10-plus-nap | waf,dos |
all-images | Builds 18 variants | - |
push | docker push to PREFIX:TAG | - |
patch-os | OS patches existing image | - |
Plus images receive $(PLUS_ARGS): --secret id=nginx-repo.crt --secret id=nginx-repo.key.
TARGET Variable
| Target | Use Case |
|---|
local | Default -- binary pre-built on host, copied in |
container | Binary built inside Docker (multi-arch capable) |
goreleaser | Binary from GoReleaser dist/ (CI builds) |
debug | Includes delve debugger |
download | Extracts binary from published Docker Hub image |
aws | AWS marketplace variant |
patched | OS patches an existing image |
Key Build Args
| Arg | Purpose | Example |
|---|
BUILD_OS | Base image stage | debian, alpine-plus, ubi-10-plus-nap |
IC_VERSION | Ingress controller version | 5.5.0 |
NGINX_PLUS_VERSION | NGINX Plus version | R36 |
NAP_MODULES | App Protect modules | waf, dos, waf,dos |
PREBUILT_BASE_IMG | Base for prebuilt targets | GCR image ref |
Build Scripts (build/scripts/)
| Script | Purpose |
|---|
common.sh | Sets up directories, copies NGINX templates (v1/v2), sets file permissions (101:0), runs setcap on nginx binaries |
agent.sh | Configures nginx-agent ownership; creates NMS compiler symlinks for NAP v4 |
nap-waf.sh | Creates WAF directories (/etc/nginx/waf/nac-policies, /opt/app_protect/) |
nap-dos.sh | Creates DoS directories (/root/app_protect_dos, /shared/cores) |
ubi-setup.sh | UBI-specific: installs shadow-utils, creates nginx user/group (101:0) |
ubi-clean.sh | UBI-specific: removes build-time packages, cleans dnf cache |
Key Conventions
- All images run as UID 101 (nginx user), with
setcap cap_net_bind_service for ports 80/443
- Docker BuildKit always enabled: uses
--mount=type=bind, --mount=type=secret, --mount=type=cache
- Plus credentials use
--secret mounts, never COPY into layers
- Fixed upstream base images use pinned
@sha256: digests for reproducibility; some stages intentionally use build-arg/tag-selected bases (for example BUILD_OS or download/prebuilt images)
- All images include
nginx-module-otel (OpenTelemetry) and nginx-agent (usage reporting)
- Plus images add
njs and fips-check modules
- Renovate manages base image digests and tool versions via
# renovate: comments
Gotchas
- Never store Plus credentials in image layers -- always use
--secret mounts
- Never add
arm64 to NAP image matrices -- NAP is amd64 only
- Always use
BUILD_OS to select variants, not separate Dockerfiles
- The
common stage unifies all variants -- changes there affect every image
common.sh detects Plus via BUILD_OS containing "plus" and creates OIDC directoriespatch-os.sh handles OS-level security updates at build time- When adding new image dependencies, update the relevant OS-specific stage AND the common stage if needed
