Update Dockerfile (#2342)

Updates/adds a new multistage (build-kit) Dockerfile. (if accepted,
could make `Dockerfile.monolith` and `Dockerfile.polylith` in
`build/docker` obsolete)
There's no huge difference between the dockerfiles, except this uses a
non-root user when running the container, also doesn't copy the working
directory to the image when building.
Also adds vulnerabilities scans using
[Trivy](https://github.com/aquasecurity/trivy) for the created docker
images. (untested)

Building images is done using 
```
docker build . --target image-monolith -t dendrite-monolith
docker build . --target image-polylith -t dendrite-polylith
```

As noted in the comments, only adds `dendrite-polylith-multi` to the
polylith image and all required binaries to the monolith image.
Probably needs some docs updating, if this is accepted.

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

13 files changed, 257 insertions, 115 deletions

diff --git a/.github/workflows/dendrite.yml b/.github/workflows/dendrite.yml
index be3c7c17..524d3603 100644
--- a/.github/workflows/dendrite.yml
+++ b/.github/workflows/dendrite.yml
@@ -284,7 +284,7 @@ jobs:
         API: ${{ matrix.api && 1 }}
         SYTEST_BRANCH: ${{ github.head_ref }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Run Sytest
         run: /bootstrap.sh dendrite
         working-directory: /src
@@ -344,8 +344,8 @@ jobs:
           sudo apt-get update && sudo apt-get install -y libolm3 libolm-dev
           go get -v github.com/haveyoudebuggedit/gotestfmt/v2/cmd/gotestfmt@latest
 
-      - name: Run actions/checkout@v2 for dendrite
-        uses: actions/checkout@v2
+      - name: Run actions/checkout@v3 for dendrite
+        uses: actions/checkout@v3
         with:
           path: dendrite
 
diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index b4e24e52..358037c0 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -21,26 +21,32 @@ jobs:
   monolith:
     name: Monolith image
     runs-on: ubuntu-latest
+    needs: build-flags
     permissions:
       contents: read
       packages: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
-      - name: Get release tag
+        uses: actions/checkout@v3
+      - name: Get release tag & build flags
         if: github.event_name == 'release' # Only for GitHub releases
-        run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+        run: |
+          echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+          echo "BUILD=$(git rev-parse --short HEAD || "") >> $GITHUB_ENV
+          BRANCH=$(git symbolic-ref --short HEAD | tr -d \/)
+          [ ${BRANCH} == "main" ] && BRANCH=""
+          echo "BRANCH=${BRANCH}" >> $GITHUB_ENV
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
+        uses: docker/setup-buildx-action@v2
       - name: Login to Docker Hub
-        uses: docker/login-action@v1
+        uses: docker/login-action@v2
         with:
           username: ${{ env.DOCKER_HUB_USER }}
           password: ${{ secrets.DOCKER_TOKEN }}
       - name: Login to GitHub Containers
-        uses: docker/login-action@v1
+        uses: docker/login-action@v2
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -49,27 +55,41 @@ jobs:
       - name: Build main monolith image
         if: github.ref_name == 'main'
         id: docker_build_monolith
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max
           context: .
-          file: ./build/docker/Dockerfile.monolith
+          build-args: FLAGS="-X github.com/matrix-org/dendrite/internal.branch=${{ env.BRANCH }} -X github.com/matrix-org/dendrite/internal.build=${{ env.BUILD }}"
+          target: monolith
           platforms: ${{ env.PLATFORMS }}
           push: true
           tags: |
             ${{ env.DOCKER_NAMESPACE }}/dendrite-monolith:${{ github.ref_name }}
             ghcr.io/${{ env.GHCR_NAMESPACE }}/dendrite-monolith:${{ github.ref_name }}
 
+      - name: Run Trivy vulnerability scanner
+        uses: aquasecurity/trivy-action@master
+        with:
+          image-ref: ghcr.io/${{ env.GHCR_NAMESPACE }}/dendrite-monolith:${{ github.ref_name }}
+          format: "sarif"
+          output: "trivy-results.sarif"
+
+      - name: Upload Trivy scan results to GitHub Security tab
+        uses: github/codeql-action/upload-sarif@v1
+        with:
+          sarif_file: "trivy-results.sarif"
+
       - name: Build release monolith image
         if: github.event_name == 'release' # Only for GitHub releases
         id: docker_build_monolith_release
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max
           context: .
-          file: ./build/docker/Dockerfile.monolith
+          build-args: FLAGS="-X github.com/matrix-org/dendrite/internal.branch=${{ env.BRANCH }} -X github.com/matrix-org/dendrite/internal.build=${{ env.BUILD }}"
+          target: monolith
           platforms: ${{ env.PLATFORMS }}
           push: true
           tags: |
@@ -81,26 +101,32 @@ jobs:
   polylith:
     name: Polylith image
     runs-on: ubuntu-latest
+    needs: build-flags
     permissions:
       contents: read
       packages: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
-      - name: Get release tag
+        uses: actions/checkout@v3
+      - name: Get release tag & build flags
         if: github.event_name == 'release' # Only for GitHub releases
-        run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+        run: |
+          echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+          echo "BUILD=$(git rev-parse --short HEAD || "") >> $GITHUB_ENV
+          BRANCH=$(git symbolic-ref --short HEAD | tr -d \/)
+          [ ${BRANCH} == "main" ] && BRANCH=""
+          echo "BRANCH=${BRANCH}" >> $GITHUB_ENV
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
+        uses: docker/setup-buildx-action@v2
       - name: Login to Docker Hub
-        uses: docker/login-action@v1
+        uses: docker/login-action@v2
         with:
           username: ${{ env.DOCKER_HUB_USER }}
           password: ${{ secrets.DOCKER_TOKEN }}
       - name: Login to GitHub Containers
-        uses: docker/login-action@v1
+        uses: docker/login-action@v2
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -109,27 +135,40 @@ jobs:
       - name: Build main polylith image
         if: github.ref_name == 'main'
         id: docker_build_polylith
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max
           context: .
-          file: ./build/docker/Dockerfile.polylith
+          build-args: FLAGS="-X github.com/matrix-org/dendrite/internal.branch=${{ env.BRANCH }} -X github.com/matrix-org/dendrite/internal.build=${{ env.BUILD }}"
+          target: polylith
           platforms: ${{ env.PLATFORMS }}
           push: true
           tags: |
             ${{ env.DOCKER_NAMESPACE }}/dendrite-polylith:${{ github.ref_name }}
             ghcr.io/${{ env.GHCR_NAMESPACE }}/dendrite-polylith:${{ github.ref_name }}
 
+      - name: Run Trivy vulnerability scanner
+        uses: aquasecurity/trivy-action@master
+        with:
+          image-ref: ghcr.io/${{ env.GHCR_NAMESPACE }}/dendrite-polylith:${{ github.ref_name }}
+          format: "sarif"
+          output: "trivy-results.sarif"
+
+      - name: Upload Trivy scan results to GitHub Security tab
+        uses: github/codeql-action/upload-sarif@v1
+        with:
+          sarif_file: "trivy-results.sarif"
+
       - name: Build release polylith image
         if: github.event_name == 'release' # Only for GitHub releases
         id: docker_build_polylith_release
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max
           context: .
-          file: ./build/docker/Dockerfile.polylith
+          target: polylith
           platforms: ${{ env.PLATFORMS }}
           push: true
           tags: |
@@ -141,26 +180,32 @@ jobs:
   demo-pinecone:
     name: Pinecone demo image
     runs-on: ubuntu-latest
+    needs: build-flags
     permissions:
       contents: read
       packages: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
-      - name: Get release tag
+        uses: actions/checkout@v3
+      - name: Get release tag & build flags
         if: github.event_name == 'release' # Only for GitHub releases
-        run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+        run: |
+          echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+          echo "BUILD=$(git rev-parse --short HEAD || "") >> $GITHUB_ENV
+          BRANCH=$(git symbolic-ref --short HEAD | tr -d \/)
+          [ ${BRANCH} == "main" ] && BRANCH=""
+          echo "BRANCH=${BRANCH}" >> $GITHUB_ENV
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
+        uses: docker/setup-buildx-action@v2
       - name: Login to Docker Hub
-        uses: docker/login-action@v1
+        uses: docker/login-action@v2
         with:
           username: ${{ env.DOCKER_HUB_USER }}
           password: ${{ secrets.DOCKER_TOKEN }}
       - name: Login to GitHub Containers
-        uses: docker/login-action@v1
+        uses: docker/login-action@v2
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -169,12 +214,12 @@ jobs:
       - name: Build main pinecone demo image
         if: github.ref_name == 'main'
         id: docker_build_demo_pinecone
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max
           context: .
-          file: ./build/docker/Dockerfile.demo-pinecone
+          target: demo-pinecone
           platforms: ${{ env.PLATFORMS }}
           push: true
           tags: |
@@ -184,12 +229,13 @@ jobs:
       - name: Build release pinecone demo image
         if: github.event_name == 'release' # Only for GitHub releases
         id: docker_build_demo_pinecone_release
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max
           context: .
-          file: ./build/docker/Dockerfile.demo-pinecone
+          build-args: FLAGS="-X github.com/matrix-org/dendrite/internal.branch=${{ env.BRANCH }} -X github.com/matrix-org/dendrite/internal.build=${{ env.BUILD }}"
+          target: demo-pinecone
           platforms: ${{ env.PLATFORMS }}
           push: true
           tags: |
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 00000000..bf583183
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,99 @@
+#syntax=docker/dockerfile:1.2
+
+#
+# base installs required dependencies and runs go mod download to cache dependencies
+#
+FROM --platform=${BUILDPLATFORM} docker.io/golang:1.19-alpine AS base
+RUN apk --update --no-cache add bash build-base curl
+
+#
+# build creates all needed binaries
+#
+FROM base AS build
+WORKDIR /src
+ARG TARGETOS
+ARG TARGETARCH
+ARG FLAGS
+RUN --mount=target=. \
+    --mount=type=cache,target=/root/.cache/go-build \
+    sh ./build/docker/crossbuild.sh
+
+#
+# The dendrite base image; mainly creates a user and switches to it
+#
+FROM alpine:latest AS dendrite-base
+LABEL org.opencontainers.image.description="Next-generation Matrix homeserver written in Go"
+LABEL org.opencontainers.image.source="https://github.com/matrix-org/dendrite"
+LABEL org.opencontainers.image.licenses="Apache-2.0"
+LABEL org.opencontainers.image.documentation="https://matrix-org.github.io/dendrite/"
+LABEL org.opencontainers.image.vendor="The Matrix.org Foundation C.I.C."
+RUN addgroup dendrite && adduser dendrite -G dendrite -u 1337 -D
+USER dendrite
+WORKDIR /home/dendrite
+
+#
+# Builds the polylith image and only contains the polylith binary
+#
+FROM dendrite-base AS polylith
+LABEL org.opencontainers.image.title="Dendrite (Polylith)"
+
+COPY --from=build /out/dendrite-polylith-multi /usr/bin/
+
+ENTRYPOINT ["/usr/bin/dendrite-polylith-multi"]
+
+#
+# Builds the monolith image and contains all required binaries
+#
+FROM dendrite-base AS monolith
+LABEL org.opencontainers.image.title="Dendrite (Monolith)"
+
+COPY --from=build /out/create-account /usr/bin/create-account
+COPY --from=build /out/generate-config /usr/bin/generate-config
+COPY --from=build /out/generate-keys /usr/bin/generate-keys
+COPY --from=build /out/dendrite-monolith-server /usr/bin/dendrite-monolith-server
+
+ENTRYPOINT ["/usr/bin/dendrite-monolith-server"]
+EXPOSE 8008 8448
+
+#
+# Builds the P2P demo image and contains all required binaries
+#
+FROM dendrite-base AS demo-pinecone
+LABEL org.opencontainers.image.title="Dendrite (P2P Demo)"
+
+COPY --from=build /out/create-account /usr/bin/create-account
+COPY --from=build /out/generate-config /usr/bin/generate-config
+COPY --from=build /out/generate-keys /usr/bin/generate-keys
+COPY --from=build /out/dendrite-demo-pinecone /usr/bin/dendrite-demo-pinecone
+
+VOLUME /etc/dendrite
+WORKDIR /etc/dendrite
+
+ENTRYPOINT ["/usr/bin/dendrite-demo-pinecone"]
+EXPOSE 8008 8448
+
+#
+# Builds the Complement image, used for integration tests
+#
+FROM base AS complement
+LABEL org.opencontainers.image.title="Dendrite (Complement)"
+RUN apk add --no-cache sqlite openssl ca-certificates
+COPY --from=build /out/* /usr/bin/
+RUN rm /usr/bin/dendrite-polylith-multi /usr/bin/dendrite-demo* /usr/bin/dendritejs-pinecone
+
+WORKDIR /dendrite
+RUN /usr/bin/generate-keys --private-key matrix_key.pem && \
+    mkdir /ca && \
+    openssl genrsa -out /ca/ca.key 2048 && \
+    openssl req -new -x509 -key /ca/ca.key -days 3650 -subj "/C=GB/ST=London/O=matrix.org/CN=Complement CA" -out /ca/ca.crt
+
+ENV SERVER_NAME=localhost
+ENV API=0
+EXPOSE 8008 8448
+
+# At runtime, generate TLS cert based on the CA now mounted at /ca
+# At runtime, replace the SERVER_NAME with what we are told
+CMD /usr/bin/generate-keys --server $SERVER_NAME --tls-cert server.crt --tls-key server.key --tls-authority-cert /ca/ca.crt --tls-authority-key /ca/ca.key && \
+    /usr/bin/generate-config -server $SERVER_NAME --ci > dendrite.yaml && \
+    cp /ca/ca.crt /usr/local/share/ca-certificates/ && update-ca-certificates && \
+    /usr/bin/dendrite-monolith-server --really-enable-open-registration --tls-cert server.crt --tls-key server.key --config dendrite.yaml -api=${API:-0}
\ No newline at end of file
diff --git a/cmd/dendritejs-pinecone/jsServer.go b/build/dendritejs-pinecone/jsServer.go
index 4298c2ae..4298c2ae 100644
--- a/cmd/dendritejs-pinecone/jsServer.go
+++ b/build/dendritejs-pinecone/jsServer.go
diff --git a/cmd/dendritejs-pinecone/main.go b/build/dendritejs-pinecone/main.go
index e070173a..e070173a 100644
--- a/cmd/dendritejs-pinecone/main.go
+++ b/build/dendritejs-pinecone/main.go
diff --git a/cmd/dendritejs-pinecone/main_noop.go b/build/dendritejs-pinecone/main_noop.go
index 0cc7e47e..0cc7e47e 100644
--- a/cmd/dendritejs-pinecone/main_noop.go
+++ b/build/dendritejs-pinecone/main_noop.go
diff --git a/cmd/dendritejs-pinecone/main_test.go b/build/dendritejs-pinecone/main_test.go
index 17fea6cc..17fea6cc 100644
--- a/cmd/dendritejs-pinecone/main_test.go
+++ b/build/dendritejs-pinecone/main_test.go
diff --git a/build/docker/Dockerfile.demo-pinecone b/build/docker/Dockerfile.demo-pinecone
deleted file mode 100644
index 133c63c5..00000000
--- a/build/docker/Dockerfile.demo-pinecone
+++ /dev/null
@@ -1,25 +0,0 @@
-FROM docker.io/golang:1.19-alpine AS base
-
-RUN apk --update --no-cache add bash build-base
-
-WORKDIR /build
-
-COPY . /build
-
-RUN mkdir -p bin
-RUN go build -trimpath -o bin/ ./cmd/dendrite-demo-pinecone
-RUN go build -trimpath -o bin/ ./cmd/create-account
-RUN go build -trimpath -o bin/ ./cmd/generate-keys
-
-FROM alpine:latest
-LABEL org.opencontainers.image.title="Dendrite (Pinecone demo)"
-LABEL org.opencontainers.image.description="Next-generation Matrix homeserver written in Go"
-LABEL org.opencontainers.image.source="https://github.com/matrix-org/dendrite"
-LABEL org.opencontainers.image.licenses="Apache-2.0"
-
-COPY --from=base /build/bin/* /usr/bin/
-
-VOLUME /etc/dendrite
-WORKDIR /etc/dendrite
-
-ENTRYPOINT ["/usr/bin/dendrite-demo-pinecone"]
diff --git a/build/docker/Dockerfile.monolith b/build/docker/Dockerfile.monolith
deleted file mode 100644
index 3180e962..00000000
--- a/build/docker/Dockerfile.monolith
+++ /dev/null
@@ -1,25 +0,0 @@
-FROM docker.io/golang:1.19-alpine AS base
-
-RUN apk --update --no-cache add bash build-base
-
-WORKDIR /build
-
-COPY . /build
-
-RUN mkdir -p bin
-RUN go build -trimpath -o bin/ ./cmd/dendrite-monolith-server
-RUN go build -trimpath -o bin/ ./cmd/create-account
-RUN go build -trimpath -o bin/ ./cmd/generate-keys
-
-FROM alpine:latest
-LABEL org.opencontainers.image.title="Dendrite (Monolith)"
-LABEL org.opencontainers.image.description="Next-generation Matrix homeserver written in Go"
-LABEL org.opencontainers.image.source="https://github.com/matrix-org/dendrite"
-LABEL org.opencontainers.image.licenses="Apache-2.0"
-
-COPY --from=base /build/bin/* /usr/bin/
-
-VOLUME /etc/dendrite
-WORKDIR /etc/dendrite
-
-ENTRYPOINT ["/usr/bin/dendrite-monolith-server"]
diff --git a/build/docker/Dockerfile.polylith b/build/docker/Dockerfile.polylith
deleted file mode 100644
index 79f8a5f2..00000000
--- a/build/docker/Dockerfile.polylith
+++ /dev/null
@@ -1,25 +0,0 @@
-FROM docker.io/golang:1.19-alpine AS base
-
-RUN apk --update --no-cache add bash build-base
-
-WORKDIR /build
-
-COPY . /build
-
-RUN mkdir -p bin
-RUN go build -trimpath -o bin/ ./cmd/dendrite-polylith-multi
-RUN go build -trimpath -o bin/ ./cmd/create-account
-RUN go build -trimpath -o bin/ ./cmd/generate-keys
-
-FROM alpine:latest
-LABEL org.opencontainers.image.title="Dendrite (Polylith)"
-LABEL org.opencontainers.image.description="Next-generation Matrix homeserver written in Go"
-LABEL org.opencontainers.image.source="https://github.com/matrix-org/dendrite"
-LABEL org.opencontainers.image.licenses="Apache-2.0"
-
-COPY --from=base /build/bin/* /usr/bin/
-
-VOLUME /etc/dendrite
-WORKDIR /etc/dendrite
-
-ENTRYPOINT ["/usr/bin/dendrite-polylith-multi"]
diff --git a/build/docker/README.md b/build/docker/README.md
index 261519fd..14a9c859 100644
--- a/build/docker/README.md
+++ b/build/docker/README.md
@@ -9,11 +9,15 @@ They can be found on Docker Hub:
 
 ## Dockerfiles
 
-The `Dockerfile` builds the base image which contains all of the Dendrite
-components. The `Dockerfile.component` file takes the given component, as
-specified with `--buildarg component=` from the base image and produce
-smaller component-specific images, which are substantially smaller and do
-not contain the Go toolchain etc.
+The `Dockerfile` is a multistage file which can build all three Dendrite
+images depending on the supplied `--target`. From the root of the Dendrite
+repository, run:
+
+```
+docker build . --target monolith -t matrixdotorg/dendrite-monolith
+docker build . --target polylith -t matrixdotorg/dendrite-monolith
+docker build . --target demo-pinecone -t matrixdotorg/dendrite-monolith
+```
 
 ## Compose files
 
diff --git a/build/docker/crossbuild.sh b/build/docker/crossbuild.sh
new file mode 100644
index 00000000..46e5d7e9
--- /dev/null
+++ b/build/docker/crossbuild.sh
@@ -0,0 +1,67 @@
+#!/bin/sh
+set -e
+
+# In order to cross-compile with the multi-stage Docker builds, we need to
+# ensure that the suitable toolchain for cross-compiling is installed. Since
+# the images are Alpine-based, we will use musl. Download and install the
+# toolchain inside the build container.
+
+USERARCH=`go env GOARCH`
+GOARCH="$TARGETARCH"
+GOOS="linux"
+
+echo "Target arch: $TARGETARCH"
+echo "User arch:   $USERARCH"
+
+if [ "$TARGETARCH" != "$USERARCH" ]; then
+    if [ "$USERARCH" != "amd64" ]; then
+      echo "Cross-compiling only supported on amd64"
+      exit 1
+    fi
+
+    echo "Cross compile"
+    case $GOARCH in
+    arm64)
+        curl -s https://more.musl.cc/x86_64-linux-musl/aarch64-linux-musl-cross.tgz | tar xz --strip-components=1 -C /usr
+        export CC=aarch64-linux-musl-gcc
+        ;;
+
+    amd64)
+        curl -s https://more.musl.cc/x86_64-linux-musl/x86_64-linux-musl-cross.tgz | tar xz --strip-components=1 -C /usr
+        export CC=x86_64-linux-musl-gcc
+        ;;
+
+    386)
+        curl -s https://more.musl.cc/x86_64-linux-musl/i686-linux-musl-cross.tgz | tar xz --strip-components=1 -C /usr
+        export CC=i686-linux-musl-gcc
+        ;;
+
+    arm)
+        curl -s https://more.musl.cc/x86_64-linux-musl/armv7l-linux-musleabihf-cross.tgz | tar xz --strip-components=1 -C /usr
+        export CC=armv7l-linux-musleabihf-gcc
+        ;;
+
+    s390x)
+        curl -s https://more.musl.cc/x86_64-linux-musl/s390x-linux-musl-cross.tgz | tar xz --strip-components=1 -C /usr
+        export CC=s390x-linux-musl-gcc
+        ;;
+
+    ppc64le)
+        curl -s https://more.musl.cc/x86_64-linux-musl/powerpc64le-linux-musl-cross.tgz | tar xz --strip-components=1 -C /usr
+        export CC=powerpc64le-linux-musl-gcc
+        ;;
+
+    *)
+        echo "Unsupported GOARCH=${GOARCH}"
+        exit 1
+        ;;
+    esac
+else
+    echo "Native compile"
+fi
+
+# Output the go environment just in case it is useful for debugging.
+go env
+
+# Build Dendrite and tools, statically linking them.
+CGO_ENABLED=1 go build -v -ldflags="-linkmode external -extldflags -static ${FLAGS}" -trimpath -o /out/ ./cmd/...
diff --git a/build/docker/images-build.sh b/build/docker/images-build.sh
index c2c14068..1a832615 100755
--- a/build/docker/images-build.sh
+++ b/build/docker/images-build.sh
@@ -6,5 +6,6 @@ TAG=${1:-latest}
 
 echo "Building tag '${TAG}'"
 
-docker build -t matrixdotorg/dendrite-monolith:${TAG}  -f build/docker/Dockerfile.monolith .
-docker build -t matrixdotorg/dendrite-polylith:${TAG}  -f build/docker/Dockerfile.polylith .
\ No newline at end of file
+docker build . --target monolith -t matrixdotorg/dendrite-monolith:${TAG}
+docker build . --target polylith -t matrixdotorg/dendrite-monolith:${TAG}
+docker build . --target demo-pinecone -t matrixdotorg/dendrite-demo-pinecone:${TAG}
\ No newline at end of file