Make the -l flag clone and build FTL directly inside the image, rather than relying on the binary having already been build externally

Signed-off-by: Adam Warner <me@adamwarner.co.uk>

README.md

@@ -274,7 +274,7 @@ The preferred method is to clone this repository and build the image locally wit
 - `-w <branch>` / `--webbranch <branch>`: Specify Web branch
 - `-p <branch>` / `--paddbranch <branch>`: Specify PADD branch
 - `-t <tag>` / `--tag <tag>`: Specify Docker image tag (default: `pihole:local`)
-- `-l` / `--local`: Use locally built FTL binary (requires `src/pihole-FTL` file)
+- `-l` / `--local`: Clones the FTL repository and builds the binary locally
 - `use_cache`: Enable caching (by default `--no-cache` is used)
 
 If no options are specified, the following command will be executed:

build.sh

@@ -4,12 +4,12 @@
 usage() {
     echo "Usage: $0 [-l] [-f <ftl_branch>] [-c <core_branch>] [-w <web_branch>] [-t <tag>] [use_cache]"
     echo "Options:"
-    echo "  -f, --ftlbranch <branch>     Specify FTL branch (cannot be used in conjunction with -l)"
+    echo "  -f, --ftlbranch <branch>     Specify FTL branch"
     echo "  -c, --corebranch <branch>    Specify Core branch"
     echo "  -w, --webbranch <branch>     Specify Web branch"
     echo "  -p, --paddbranch <branch>    Specify PADD branch"
     echo "  -t, --tag <tag>              Specify Docker image tag (default: pihole:local)"
-    echo "  -l, --local                  Use locally built FTL binary (requires src/pihole-FTL file)"
+    echo "  -l, --local                  Clones the FTL repository and builds the binary locally"
     echo "  use_cache                    Enable caching (by default --no-cache is used)"
     echo ""
     echo "If no options are specified, the following command will be executed:"
@@ -20,11 +20,9 @@ usage() {
 # Set default values
 TAG="pihole:local"
 DOCKER_BUILD_CMD="docker buildx build src/. --tag ${TAG} --load --no-cache"
-FTL_FLAG=false
 
 # Check if buildx is installed
-docker buildx version >/dev/null 2>&1
-if [ $? -ne 0 ]; then
+if ! docker buildx version >/dev/null 2>&1; then
     echo "Error: Docker buildx is required to build this image. For installation instructions, see:"
     echo "       https://github.com/docker/buildx#installing"
     exit 1
@@ -57,24 +55,10 @@ while [[ $# -gt 0 ]]; do
 
     case $key in
     -l | --local)       
-        if [ ! -f "src/pihole-FTL" ]; then
-            echo "File 'src/pihole-FTL' not found. Exiting."
-            exit 1
-        fi
-        if [ "$FTL_FLAG" = true ]; then
-            echo "Error: Both -l and -f cannot be used together."
-            usage
-        fi
-        FTL_FLAG=true
         DOCKER_BUILD_CMD+=" --build-arg FTL_SOURCE=local"
         shift
         ;;
     -f | --ftlbranch)        
-        if [ "$FTL_FLAG" = true ]; then
-            echo "Error: Both -l and -f cannot be used together."
-            usage
-        fi
-        FTL_FLAG=true
         FTL_BRANCH="$2"
         check_branch_exists "ftl" "$FTL_BRANCH"
         DOCKER_BUILD_CMD+=" --build-arg FTL_BRANCH=$FTL_BRANCH"
@@ -122,10 +106,8 @@ done
 
 # Execute the docker build command
 echo "Executing command: $DOCKER_BUILD_CMD"
-eval "${DOCKER_BUILD_CMD}"
-
-# Check exit code of previous command
-if [ $? -ne 0 ]; then
+# Execute the docker build command and check its exit status
+if ! eval "${DOCKER_BUILD_CMD}"; then
     echo ""
     echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
     echo "!! ERROR: Docker build failed, please review logs above !!"

src/Dockerfile

@@ -86,7 +86,7 @@ EXPOSE 80
 EXPOSE 123/udp
 EXPOSE 443
 
-## Buildkit can do some fancy stuff and we can use it to either download FTL from ftl.pi-hole.net or use a local copy
+## Buildkit can do some fancy stuff and we can use it to either download FTL from ftl.pi-hole.net or build a local copy
 
 FROM base AS remote-ftl-install
 # Default stage if FTL_SOURCE is not explicitly set to "local"
@@ -106,10 +106,22 @@ RUN if   [ "$TARGETPLATFORM" = "linux/amd64" ];    then FTLARCH=amd64; \
     && readelf -h /usr/bin/pihole-FTL || (echo "Error with downloaded FTL binary" && exit 1) \
     && /usr/bin/pihole-FTL  -vv
 
+# This is only used if FTL_SOURCE is set to "local" (which will in turn use the local-ftl-install stage)
+FROM ghcr.io/pi-hole/ftl-build:v2.11 AS ftl-builder
+# Needs to be defaulted to something, but it will be overridden by the build-arg anyway
+ARG FTL_BRANCH="development"
+
+RUN git clone --depth 1 --single-branch --branch ${FTL_BRANCH} https://github.com/pi-hole/ftl.git /ftlbuild && \
+    cd /ftlbuild && \
+    rm src/args.c && \
+    ./build.sh &&\
+    # if the build fails, exit with and error code
+    if [ $? -ne 0 ]; then echo "FTL build failed" && exit 1; fi && \
+    # check if the binary is valid
+    readelf -h /ftlbuild/pihole-FTL || (echo "Error with built FTL binary" && exit 1)
+
 FROM base AS local-ftl-install
-# pihole-FTL must be built from source and copied to the src directory first!
-COPY --chmod=0755 pihole-FTL /usr/bin/pihole-FTL
-RUN  readelf -h /usr/bin/pihole-FTL || (echo "Error with local FTL binary" && exit 1)
+COPY --from=ftl-builder --chmod=0755 /ftlbuild/pihole-FTL /usr/bin/pihole-FTL
 
 # Use the appropriate FTL Install stage based on the FTL_SOURCE build-arg
 FROM ${FTL_SOURCE}-ftl-install AS final