ClearCutt
Hardened Image Blueprint
.NET
.NET 8 · Dev · Nix Builder Base

clearcutt-dotnet8 : dev

Builder tier — full toolchain, shells, debug utilities, credential helper.

v0.2.1 amd64arm64 Status: active Support: LTS Non-Prod Only Cosign signed SLSA L3 SBOM attached Scan pending Vulnerability gate passed
Multi-arch Manifest Digest:
sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15

Published Fri, 29 May 2026 13:44:59 GMT

Last Rebuilt Fri, 29 May 2026 13:44:59 GMT

Continuous Scan Active
1

About this Image & Usage

Explore container capabilities, common use cases, and complete integration blueprints.

Capabilities & Guarantees

This .NET SDK developer image delivers .NET 8 SDK, MSBuild, NuGet, and complete compiler pipelines. It is optimized for source compilation and unit testing inside OCI environments.

Common Use Cases

  • Compiling, packing, and publishing C# and F# enterprise applications from source code
  • Running MSBuild and dotnet test execution stages inside automated pipelines
  • Building highly secure C# microservices with isolated NuPkg package restores

Runtime Security & Execution Contract

Shell Presence Yes (BusyBox/Bash)
Package Manager Yes (Active)
Secure UID Operator UID 10001
Production Tier No (Dev Builder)
CA Certificates Present / Active
Timezone Data Present / Active

Developer blueprints

Copy pre-configured code structures to accelerate deployment pipelines.

Dockerfile dockerfile
# Stage 1: Build and publish .NET assembly in SDK dev builder
FROM ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev AS builder
WORKDIR /app

COPY *.csproj ./
RUN dotnet restore

COPY . .
RUN dotnet publish -c Release -o out --no-restore

# Stage 2: Hardened runner stage (distroless or slim ASP.NET runtime)
FROM ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev
WORKDIR /app

# Copy published assemblies
COPY --from=builder /app/out ./

# Set environment and run as secure non-root operator
USER 10001:10001
ENV ASPNETCORE_URLS=http://+:8080
ENV DOTNET_CLI_TELEMETRY_OPTOUT=1
CMD ["dotnet", "MyDotnetApp.dll"]

If your organization mandates a certified base OS (like Red Hat UBI, Amazon Linux, or Ubuntu Pro) for compliance, you can stack ClearCutt's RPATH-bound /nix/store closure directly on top without modifying base layers or bundled agents.

Dockerfile.overlay dockerfile
# Stage 1: Pull the ClearCutt secure runtime OCI image to extract its store
FROM ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev AS clearcutt

# Stage 2: Graft the runtime onto your mandated base OS (Red Hat UBI, AL2023, Ubuntu)
FROM registry.access.redhat.com/ubi9/ubi-minimal:9.4

# Copy the immutable Nix store closure (leaves base OS layers and agents intact)
COPY --from=clearcutt /nix /nix

# Stabilize the runtime path behind /usr/local/bin so ENTRYPOINTs survive store bumps
RUN set -eux; \
    runtime_bin="$(find /nix/store -maxdepth 3 -type f -path '*/bin/dotnet' | head -n1)"; \
    test -n "$runtime_bin"; \
    ln -sf "$runtime_bin" /usr/local/bin/dotnet; \
    /usr/local/bin/dotnet --version || /usr/local/bin/dotnet -version || true

# Set workspace and run as ClearCutt's secure non-root user (UID 10001)
WORKDIR /app
COPY . .
USER 10001:10001

ENTRYPOINT ["/usr/local/bin/dotnet"]
flake.nix nix
# Run an interactive local dev shell with the exact same remediated .NET SDK:
$ nix shell github:northcutted/clearcutt-images/v0.2.1#clearcuttDotnet8-native

# Or declare inside your local flake.nix environment:
{
  inputs.clearcutt.url = "github:northcutted/clearcutt-images/v0.2.1";
  outputs = { self, nixpkgs, clearcutt }: {
    devShells.x86_64-linux.default = let
      pkgs = import nixpkgs {
        system = "x86_64-linux";
        overlays = [ clearcutt.overlays.default ];
      };
    in pkgs.mkShell {
      buildInputs = [ pkgs.clearcuttDotnet8 ];
    };
  };
}
layer.nix nix
# Layer a .NET runtime release into a custom OCI image declaratively in Nix
pkgs.dockerTools.buildImage {
  name = "custom-dotnet-service";
  tag = "latest";
  
  # Layer on top of ClearCutt's runtime base
  fromImage = clearcutt-base-image;

  copyToRoot = pkgs.buildEnv {
    name = "image-root";
    paths = [
      dotnet-published-package # Monopackage compiled cleanly via Nix env
    ];
    pathsToLink = [ "/bin" ];
  };

  config = {
    Cmd = [ "/bin/dotnet-service" ];
    User = "10001:10001";
  };
}

Pull & Run Workspace

Select your preferred container engine or deployment platform target.

Pull by multi-arch digest (Recommended, Secure)

docker pull ghcr.io/northcutted/clearcutt/clearcutt-dotnet8@sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15

Pinned to release

docker pull ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev

Quick pull (rolling)

docker pull ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:dev

Hardened docker run

docker run --rm \
  --read-only \
  --cap-drop=ALL \
  --security-opt no-new-privileges \
  --user 10001:10001 \
  --tmpfs /tmp:mode=1777 \
  ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev

Pull by multi-arch digest (Recommended, Secure)

podman pull ghcr.io/northcutted/clearcutt/clearcutt-dotnet8@sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15

Pinned to release

podman pull ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev

Quick pull (rolling)

podman pull ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:dev

Hardened podman run

podman run --rm \
  --read-only \
  --cap-drop=ALL \
  --security-opt no-new-privileges \
  --user 10001:10001 \
  --tmpfs /tmp:mode=1777 \
  ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev
docker-compose.yml yaml
services:
  app:
    image: ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev
    read_only: true
    user: "10001:10001"
    security_opt:
      - no-new-privileges:true
    cap_drop:
      - ALL
    tmpfs:
      - /tmp:mode=1777
pod.yaml yaml
apiVersion: v1
kind: Pod
metadata:
  name: clearcutt-dotnet8
spec:
  automountServiceAccountToken: false
  securityContext:
    runAsNonRoot: true
    runAsUser: 10001
    runAsGroup: 10001
    seccompProfile: { type: RuntimeDefault }
  containers:
    - name: app
      image: ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:v0.2.1-dev
      imagePullPolicy: IfNotPresent
      securityContext:
        readOnlyRootFilesystem: true
        allowPrivilegeEscalation: false
        capabilities: { drop: ["ALL"] }
      volumeMounts:
        - { name: tmp, mountPath: /tmp }
  volumes:
    - { name: tmp, emptyDir: { medium: Memory } }
flake.nix nix
{
  inputs.clearcutt.url = "github:northcutted/clearcutt/v0.2.1";
  outputs = { self, nixpkgs, clearcutt }: {
    devShells.x86_64-linux.default = let
      pkgs = import nixpkgs {
        system = "x86_64-linux";
        overlays = [ clearcutt.overlays.default ];
      };
    in pkgs.mkShell {
      buildInputs = [ pkgs.clearcuttDotnet8 ];
    };
  };
}
2

Verify & Audit Compliance

Inspect supply chain provenance, run local cryptographic OIDC audits, and review vulnerability gates.

Provenance & signatures

Cryptographically audit OCI identity claims and supply chain gating artifacts.

raw in-toto JSONL

Cryptographic Proof

VERIFIED KEYLESS
Signing Workflow release.yml
Workflow Ref refs/heads/main
OIDC Issuer token.actions.githubusercontent.com
OIDC Certificate Subject
https://github.com/northcutted/clearcutt/.github/workflows/release.yml@refs/heads/main

Supply Chain Provenance

SLSA LEVEL 3
Build Type GitHub Actions Workflow
Predicate Schema SLSA Provenance v1.0
Source Material github.com/northcutted/clearcutt
Commit SHA d729c1c ↗
Non-falsifiable attestation: Passed

Compilation & Gates

GATES PASSED
Gating timestamp: 2026-05-29T13:18

Attestations

4 kinds of evidence for this image. The counts are how many times each was independently signed into the public transparency log — not how many distinct artifacts exist.

24 signed records
Subject ghcr.io/northcutted/clearcutt/clearcutt-dotnet8 Digest sha256:0f0dcc219810... index · amd64+arm64 Signed By release.yml @ main keyless ✓
Two ways to verify — pick the ecosystem you know
cosign · OCI Attestation lives with the image in the registry. Verify with cosign verify-attestation.
gh CLI · GitHub GitHub first-party attestation. Verify with gh attestation verify.

The subject above is the multi-arch index (amd64 + arm64). Each architecture's SBOM is attested separately, in both ecosystems — so one SBOM naturally appears as several signed records below. Records also accumulate as the image is rebuilt, with each release re-signing into the transparency log afresh. Every entry is independent and publicly verifiable: click any #index below to inspect it in Sigstore Rekor, or use the copy-paste commands below to verify them locally.

Build provenance slsa.dev/provenance/v1

How and where the image was built — binds this digest to the exact workflow run, commit, and builder.

signed
Verify with
Inspect Rekor log
SBOM spdx.dev/Document

Software Bill of Materials — the full inventory of packages baked into the image.

signed
Verify with
Inspect Rekor log
Cosign signature sigstore.dev/cosign/sign/v1

The keyless cosign signature statement covering the image index.

signed
Verify with
Inspect Rekor log

Active Verification Toolkit

Run local cryptographic OIDC audits and generate Kyverno cluster policies to enforce supply chain integrity.

Direct Cryptographic Evidence & Verification

Expected Certificate Subject https://github.com/northcutted/clearcutt/.github/workflows/release.yml@refs/heads/main
Expected Certificate OIDC Issuer https://token.actions.githubusercontent.com
Manifest Index Digest sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15
One-step Audit Command

Run the native compiled Go CLI command locally to verify the registry digest, Sigstore signature, SBOM and test attestations, and SLSA provenance:

clearcutt verify release-evidence \
  --ref ghcr.io/northcutted/clearcutt/clearcutt-dotnet8@sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15 \
  --repo northcutted/clearcutt \
  --workflow-identity 'https://github.com/northcutted/clearcutt/.github/workflows/release.yml@refs/heads/main'

1. Inspect Security Metadata

Query deep, high-fidelity security metadata, dynamic entrypoints, non-root user settings, architectures, and release asset URLs.

clearcutt inspect dotnet8-dev --tag v0.2.1

2. Local Policy Gate Verification

Enforce signatures, SBOMs, SLSA provenance, smoke tests, vulnerability limits, and lifecycle constraints locally or in CI pipelines.

clearcutt verify image dotnet8-dev \
  --tag v0.2.1 \
  --require-production \
  --require-signature \
  --require-sbom \
  --require-provenance \
  --max-critical 0 \
  --max-high 5

3. Runtime Conformance Audit

Verify runtime specifications offline, asserting timezone configurations, dynamic links, CA certificate paths, and rootless isolation boundaries.

clearcutt conformance run \
  --expect-runtime dotnet

4. Scaffold Nix Overlay Graft

Under strict corporate base OS mandates, generate a workspace scaffolding to graft this runtime overlay onto existing host layers.

clearcutt overlay generate \
  --runtime dotnet8 \
  --tier dev \
  --base registry.access.redhat.com/ubi9/ubi-minimal \
  --output my-dotnet8-overlay/

1. Verify Keyless OIDC Signature

Confirm this OCI image was built in your official release workflow and signed via keyless OIDC certificates.

cosign verify ghcr.io/northcutted/clearcutt/clearcutt-dotnet8@sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15 \
  --certificate-identity 'https://github.com/northcutted/clearcutt/.github/workflows/release.yml@refs/heads/main' \
  --certificate-oidc-issuer 'https://token.actions.githubusercontent.com' \
  --output json

2. Verify Cryptographic SBOM Attestation

Extract and cryptographically verify the compiled package software bill of materials statement.

cosign verify-attestation ghcr.io/northcutted/clearcutt/clearcutt-dotnet8@sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15 \
  --type spdxjson \
  --certificate-identity 'https://github.com/northcutted/clearcutt/.github/workflows/release.yml@refs/heads/main' \
  --certificate-oidc-issuer 'https://token.actions.githubusercontent.com' \
  | jq '.payload | @base64d | fromjson | .predicate'

slsa-verifier (SLSA Build L3)

Verify SLSA Build L3 provenance from the configured builder and source ref.

slsa-verifier verify-image ghcr.io/northcutted/clearcutt/clearcutt-dotnet8@sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15 \
  --source-uri 'github.com/northcutted/clearcutt' \
  --source-branch 'main'

GitHub Native Attestation

Audit standard GitHub OCI attestations natively using the GitHub CLI client.

gh attestation verify oci://ghcr.io/northcutted/clearcutt/clearcutt-dotnet8@sha256:0f0dcc2198105764f0ee8017cd659958a20995996fb5f7af9ecc3a06a36c7e15 \
  --repo northcutted/clearcutt \
  --cert-identity 'https://github.com/northcutted/clearcutt/.github/workflows/release.yml@refs/heads/main' \
  --source-ref refs/heads/main

Admission Control (Kyverno Policy)

Enforce keyless signature and cryptographic SBOM attestation checks in Kubernetes clusters dynamically.

Set cluster behavior on signature check failure
Block pods if they lack a cryptographically signed SPDX SBOM
policy.yaml yaml
apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: verify-clearcutt-dotnet8
spec:
  validationFailureAction: Enforce
  webhookTimeoutSeconds: 30
  rules:
    - name: verify-cosign-signature
      match:
        any:
          - resources:
              kinds: [Pod]
      verifyImages:
        - imageReferences: ["ghcr.io/northcutted/clearcutt/clearcutt-dotnet8:*"]
          attestors:
            - entries:
                - keyless:
                     subject: "https://github.com/northcutted/clearcutt/.github/workflows/release.yml@refs/heads/main"
                     issuer: "https://token.actions.githubusercontent.com"
          attestations:
            - predicateType: "https://spdx.dev/Document"
              attestors:
                - entries:
                    - keyless:
                        subject: "https://github.com/northcutted/clearcutt/.github/workflows/release.yml@refs/heads/main"
                        issuer: "https://token.actions.githubusercontent.com"
          mutateDigest: true
          verifyDigest: true
          required: true
No vulnerability data is attached yet. This page will show fix status after the next catalog refresh.
3

Deep-Dive & OCI Specifications

Analyze the full Nix store dependency closure, image layer architecture, and OCI configuration labels.

Software Bill of Materials

Every package included in the image's /nix/store closure. Generated from the actual OCI archive at build time and attached as an SPDX SBOM, using the same package inventory as the CVE findings above.

SBOM generated Fri, 29 May 2026 13:17:32 GMT. Toggle between architectures; the package set typically matches but layer hashes differ.

Arch:
2319 packages indexedRaw SPDX
Filter by Type:
License:
Search packages
2319/2319 matched

Layer explorer

Click any layer card in the cohesive OCI stack below to inspect its digest, size, packages, and vulnerability density.

OCI Image Layer Stack (99 layers)total 387.2 MB
Layer
#1 of 99
Position
base
Digest
sha256:27bc2324368427854627709b86a938d207b1ec8f992f5c587a7648d2b225593b
Size
5.34 KB
% of image
0.0%
Cumulative
5.34 KB
Pull or Inspect Layer
crane blob ghcr.io/northcutted/clearcutt/clearcutt-dotnet8@sha256:27bc2324368427854627709b86a938d207b1ec8f992f5c587a7648d2b225593b
Layer Security Status✓ SECURE

No known vulnerabilities are introduced by the packages compiled in this specific Nix closure layer.

License Composition
NOASSERTION (1)

Nix closures trace full direct/transitive dependency trees, meaning all runtime libraries are cataloged with zero-trust cryptographic precision.

Image Specifications & Release Ledger

Inspect the static OCI container metadata labels and browse the immutable published release history for this image.

KeyValue
org.opencontainers.image.authors Eddie Northcutt
org.opencontainers.image.description Hardened ClearCutt Base Image for dotnet (8) - Tier: dev
org.opencontainers.image.licenses Apache-2.0
org.opencontainers.image.ref.name dev
org.opencontainers.image.source https://github.com/northcutted/clearcutt
org.opencontainers.image.title clearcutt-dotnet-8
org.opencontainers.image.url https://github.com/northcutted/clearcutt
org.opencontainers.image.vendor Eddie Northcutt
org.opencontainers.image.version 8
Tag Published Archs Packages
v0.8.1 latest Thu, 04 Jun 2026 00:36:30 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.8.0 Wed, 03 Jun 2026 01:16:58 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.7.2 Sun, 31 May 2026 16:32:29 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.7.0 Sun, 31 May 2026 00:59:17 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.6.5 Sat, 30 May 2026 19:24:38 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.6.4 Sat, 30 May 2026 17:13:43 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.6.3 Sat, 30 May 2026 16:09:42 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.5.0 Sat, 30 May 2026 03:49:37 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.4.1 Fri, 29 May 2026 23:48:33 GMT amd64arm64 2319 .intoto.jsonl ↗
v0.2.1 Fri, 29 May 2026 13:44:59 GMT amd64arm64 2319 .intoto.jsonl ↗