fix: more work on optimization proliferation of docker layers

Signed-off-by: Nick Mitchell <[email protected]>

Author: starpit

.dockerignore

@@ -4,5 +4,5 @@
 /tests
 .git
 *.log
-*~
-*.tar.gz
+**/*~
+**/*.tar.gz

Dockerfile

@@ -1,29 +1,36 @@
-FROM docker.io/golang:1.22.6-alpine as builder
+# download go modules
+FROM docker.io/golang:1.22.6-alpine as base
+LABEL lunchpail=temp
 WORKDIR /init
 
 ENV CGO_ENABLED=0
-COPY go.* .
-RUN go mod download
+
+COPY go.mod .
+COPY go.sum .
+RUN --mount=type=cache,target=/root/.cache/go-build --mount=type=cache,target=/go/pkg/mod go mod download -x
 
 COPY cmd cmd
 COPY pkg pkg
 COPY charts charts
 
 # build the CLI
-RUN go generate ./... && \
+FROM base as builder
+LABEL lunchpail=temp
+RUN --mount=type=cache,target=/root/.cache/go-build --mount=type=cache,target=/go/pkg/mod \
+    go generate ./... && \
     go generate ./... && \
-    go build -ldflags="-s -w" -o lunchpail cmd/main.go && \
-    chmod a+rX lunchpail && \
-    find . -name '*.tar.gz' -exec rm {} \;
+    go build -ldflags="-s -w" -o /tmp/lunchpail cmd/main.go && \
+    find . -name '*.tar.gz' -exec rm {} \; && \
+    chmod a+rX /tmp/lunchpail
 
 FROM docker.io/alpine:3
-LABEL org.opencontainers.image.source="https://github.com/IBM/lunchpail"
+LABEL lunchpail=final org.opencontainers.image.source="https://github.com/IBM/lunchpail"
 
 RUN adduser -u 2000 lunchpail -G root --disabled-password && echo "lunchpail:lunchpail" | chpasswd && chmod -R g=u /home/lunchpail
 ENV HOME=/home/lunchpail
 WORKDIR /home/lunchpail
 
-COPY --from=builder /init/lunchpail /usr/local/bin/lunchpail
+COPY --from=builder /tmp/lunchpail /usr/local/bin/lunchpail
 
 USER lunchpail
 CMD ["lunchpail"]

pkg/lunchpail/images/build/buildImage.go

@@ -85,6 +85,14 @@ func buildIt(dir, name, dockerfile string, kind ImageOrManifest, cli ContainerCl
 			".",
 		)
 	} else {
+		// clean out prior "final" and "temp" layers before building a new one
+		if err := clean(cli, "final"); err != nil {
+			return "", err
+		}
+		if err := clean(cli, "temp"); err != nil {
+			return "", err
+		}
+
 		cmd = exec.Command(
 			string(cli),
 			"build",
@@ -119,6 +127,20 @@ func buildIt(dir, name, dockerfile string, kind ImageOrManifest, cli ContainerCl
 	// TODO --build-arg registry=$IMAGE_REGISTRY --build-arg repo=$IMAGE_REPO --build-arg version=$VERSION \
 }
 
+func clean(cli ContainerCli, label string) error {
+	cmd := exec.Command(
+		string(cli),
+		"image",
+		"prune",
+		"--force",
+		"--filter",
+		"label=lunchpail="+label,
+	)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	return cmd.Run()
+}
+
 func buildProd(dir, name, dockerfile string, cli ContainerCli, verbose bool, force bool) (string, error) {
 	image := imageName(name)