fix(docker): scope build context to docker/ so it builds standalone (#7513)

COPY docker/apache.conf and docker/entrypoint.sh only resolve when the
build context is the repo root. Building directly from docker/ (docker
build .) fails because those paths don't exist relative to that
context. Neither COPY step needs anything outside docker/, so narrow
the context instead of requiring root.

Fixes #7512

Signed-off-by: Thomas Vincent <thomasvincent@gmail.com>
Co-authored-by: TheWitness <thewitness@cacti.net>

docker-compose.yml

@@ -10,8 +10,8 @@
 services:
   web:
     build:
-      context: .
+      context: ./docker
-      dockerfile: docker/Dockerfile
+      dockerfile: Dockerfile
     container_name: cacti_web
     ports:
       - "${WEB_PORT:-8080}:80"

docker/Dockerfile

@@ -34,7 +34,7 @@ RUN a2enmod rewrite headers proxy proxy_fcgi setenvif \
     && a2dismod mpm_prefork \
     && a2enmod mpm_event
 
-COPY docker/apache.conf /etc/apache2/sites-available/cacti.conf
+COPY apache.conf /etc/apache2/sites-available/cacti.conf
 RUN a2dissite 000-default && a2ensite cacti
 
 # Static PHP settings (runtime-tunable values are set in entrypoint.sh)
@@ -72,7 +72,7 @@ RUN mkdir -p /var/www/html/cacti/cache \
              /var/www/html/cacti/log \
     && chown -R www-data:www-data /var/www/html/cacti
 
-COPY docker/entrypoint.sh /usr/local/bin/entrypoint.sh
+COPY entrypoint.sh /usr/local/bin/entrypoint.sh
 RUN chmod +x /usr/local/bin/entrypoint.sh
 
 # App code comes from the docker-compose bind mount, not from this image.