deploy: cross-compile arm64 binaries on the dev machinev0.1.13

The target only assembles the image from prebuilt binaries, so redeploys
no longer compile sqlite/argon2 on the NAS. New deploy/Dockerfile.cross
provides the gcc-aarch64-linux-gnu toolchain; the Dockerfile uses
.prebuilt/ when present.

7 files changed, 51 insertions, 4 deletions

diff --git a/.dockerignore b/.dockerignore
index 110fe6f..6e6f325 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -1,5 +1,6 @@
 .git
 .github
+.prebuilt/
 build/
 var/
 .env
diff --git a/.gitignore b/.gitignore
index 811ddc5..13080ca 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 build/
+.prebuilt/
 *.o
 *.a
 *.db
diff --git a/Dockerfile b/Dockerfile
index d658d70..41e2895 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,14 @@ RUN apt-get update \
  && rm -rf /var/lib/apt/lists/*
 WORKDIR /src
 COPY . .
-RUN make -j"$(nproc)" VERSION="$VERSION" && make test VERSION="$VERSION"
+# With .prebuilt/ the binaries are cross-compiled on the development machine
+# (see deploy/Dockerfile.cross); otherwise build and test from source.
+RUN if [ -x .prebuilt/bokfd ]; then \
+        mkdir -p build && \
+        cp .prebuilt/bokfd .prebuilt/bokfctl .prebuilt/bokftui build/; \
+    else \
+        make -j"$(nproc)" VERSION="$VERSION" && make test VERSION="$VERSION"; \
+    fi
 
 FROM debian:bookworm-slim AS runtime
 RUN apt-get update \
diff --git a/Makefile b/Makefile
index 418dc8e..d35176b 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@ DEPFLAGS = -MMD -MP
 CPPFLAGS = -Isrc -Iclients -Ivendor -Ivendor/argon2
 DEFS     = -D_GNU_SOURCE -DARGON2_NO_THREADS -DBOKF_VERSION=\"$(VERSION)\"
 
-BUILD = build
+BUILD ?= build
 
 VENDOR_SRC = vendor/sqlite3.c vendor/yyjson.c vendor/sha256.c \
              vendor/argon2/argon2.c vendor/argon2/core.c \
diff --git a/deploy/Dockerfile.cross b/deploy/Dockerfile.cross
new file mode 100644
index 0000000..9a568cf
--- /dev/null
+++ b/deploy/Dockerfile.cross
@@ -0,0 +1,12 @@
+# Cross-compile the arm64 binaries on an amd64 host. The runtime image is
+# assembled later on the target host from the produced binaries.
+FROM debian:bookworm
+RUN dpkg --add-architecture arm64 \
+ && apt-get update \
+ && apt-get install -y --no-install-recommends \
+      make ca-certificates gcc-aarch64-linux-gnu \
+      libncurses-dev:arm64 libssl-dev:arm64 \
+ && rm -rf /var/lib/apt/lists/*
+COPY cross-build.sh /usr/local/bin/cross-build
+RUN chmod 0755 /usr/local/bin/cross-build
+ENTRYPOINT ["/usr/local/bin/cross-build"]
diff --git a/deploy/cross-build.sh b/deploy/cross-build.sh
new file mode 100644
index 0000000..7c90b0f
--- /dev/null
+++ b/deploy/cross-build.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+# Cross-compile bokfd/bokfctl/bokftui for aarch64. Expects the source
+# read-only at /src, writes the binaries to /out and takes the version from
+# $VERSION. Run through deploy/Dockerfile.cross.
+set -eu
+
+make -C /src -j"$(nproc)" BUILD=/tmp/build \
+    CC=aarch64-linux-gnu-gcc \
+    CFLAGS="-O2 -g -L/usr/lib/aarch64-linux-gnu" \
+    VERSION="${VERSION:-0.1.0-dev}"
+
+mkdir -p /out
+cp /tmp/build/bokfd /tmp/build/bokfctl /tmp/build/bokftui /out/
diff --git a/scripts/deploy.sh b/scripts/deploy.sh
index 25c86dc..c345a21 100755
--- a/scripts/deploy.sh
+++ b/scripts/deploy.sh
@@ -47,7 +47,7 @@ case "$BOKF_BUILD" in
         if [ "$(uname -m)" = "$host_arch" ]; then
             BOKF_BUILD=local
         else
-            echo "deploy: host is $host_arch, building there"
+            echo "deploy: host is $host_arch, cross-building here"
             BOKF_BUILD=remote
         fi
         ;;
@@ -64,12 +64,25 @@ if [ "$BOKF_BUILD" = local ]; then
     echo "deploy: shipping image to $BOKF_HOST"
     docker save "bokf:$TAG" | gzip | "${SSH[@]}" 'gunzip | docker load'
 else
-    echo "deploy: building image bokf:$TAG on $BOKF_HOST"
+    echo "deploy: cross-compiling $host_arch binaries on this machine"
+    rm -rf .prebuilt
+    mkdir -p .prebuilt
+    docker build -q -f deploy/Dockerfile.cross -t bokf-cross deploy/ >/dev/null
+    docker run --rm -e "VERSION=$TAG" -v "$PWD":/src:ro \
+        -v "$PWD/.prebuilt":/out bokf-cross
+    if command -v file >/dev/null 2>&1 &&
+        ! file .prebuilt/bokfd | grep -q aarch64; then
+        echo "deploy: cross-build produced no arm64 binary" >&2
+        rm -rf .prebuilt
+        exit 1
+    fi
+    echo "deploy: assembling image bokf:$TAG on $BOKF_HOST"
     tar -cf - \
         --exclude=./.git --exclude=./build --exclude=./var --exclude=./.env \
         --exclude='./*.se' --exclude='./*.db' --exclude='./*.db-wal' \
         --exclude='./*.db-shm' --exclude=./docs . |
         "${SSH[@]}" "docker build --build-arg 'VERSION=$TAG' -t 'bokf:$TAG' -"
+    rm -rf .prebuilt
 fi
 
 remote "mkdir -p '$BOKF_REMOTE_DIR'"