feat: add multi-stage copy-path lab idea

labs/docker-multi-stage-copy-path/cloud-init.yaml

@@ -0,0 +1,15 @@
+#cloud-config
+packages:
+  - docker.io
+runcmd:
+  - mkdir -p /opt/brokenops/docker-multi-stage-copy-path
+  - |
+    cat <<'EOF' > /opt/brokenops/docker-multi-stage-copy-path/Dockerfile
+    FROM alpine:3.19 AS builder
+    RUN mkdir -p /out && echo 'BrokenOps multi-stage build' > /out/app.txt
+
+    FROM alpine:3.19
+    COPY --from=builder /out/app.tx /app/app.txt
+    CMD ["cat", "/app/app.txt"]
+    EOF
+  - chown -R root:root /opt/brokenops/docker-multi-stage-copy-path

labs/docker-multi-stage-copy-path/lab.yaml

@@ -0,0 +1,13 @@
+id: "docker-multi-stage-copy-path"
+name: "Docker Multi-Stage COPY Path"
+category: "docker"
+difficulty: "intermediate"
+description:
+  summary: "A multi-stage Docker build fails because the final stage copies from the wrong artifact path."
+vm:
+  name: "docker-copy-lab"
+  memory: 2048
+  cpu: 2
+  disk: "10G"
+cloud_init: "cloud-init.yaml"
+verify_script: "verify.sh"

labs/docker-multi-stage-copy-path/question.md

@@ -0,0 +1,10 @@
+### Scenario
+A container image stopped building after a refactor changed the artifact path in a multi-stage Dockerfile.
+
+### Objective
+Fix the Dockerfile so the final image can be built and run successfully again.
+
+### Useful Commands
+- `docker build .`
+- `docker run --rm <image>`
+- `sed -n '1,120p' Dockerfile`

labs/docker-multi-stage-copy-path/solution.md

@@ -0,0 +1,19 @@
+### The Issue
+The final Docker stage is copying the built artifact from the wrong path. The builder creates `/out/app.txt`, but the final stage tries to copy `/out/app.tx`.
+
+### Step-by-Step Fix
+
+1. **Inspect the Dockerfile**:
+   Read the multi-stage build and confirm the artifact name in the builder stage.
+
+2. **Correct the `COPY` source path**:
+   Update the final stage so it copies `/out/app.txt` into the runtime image.
+
+3. **Rebuild the image**:
+   Build the image again and make sure the Docker build completes without errors.
+
+4. **Run the container**:
+   Start the built image and confirm it prints `BrokenOps multi-stage build`.
+
+5. **Verify the fix**:
+   Once the build and run both succeed, the lab is solved.

labs/docker-multi-stage-copy-path/solution.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+set -euo pipefail
+cd /opt/brokenops/docker-multi-stage-copy-path
+sed -i 's/app.tx/app.txt/' Dockerfile

labs/docker-multi-stage-copy-path/verify.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+set -euo pipefail
+cd /opt/brokenops/docker-multi-stage-copy-path
+if ! docker build -t brokenops-multi-stage-copy . >/tmp/brokenops-multi-stage-build.log 2>&1; then
+  cat /tmp/brokenops-multi-stage-build.log
+  exit 1
+fi
+if ! docker run --rm brokenops-multi-stage-copy sh -c 'test "$(cat /app/app.txt)" = "BrokenOps multi-stage build"'; then
+  docker run --rm brokenops-multi-stage-copy cat /app/app.txt || true
+  exit 1
+fi
+echo "SUCCESS: The multi-stage build produces the expected artifact."
+exit 0