generate.pl: Add Dockerfile changes for debug builds

- Install gdb
- Set debugging flags
- Slightly refactor Dockerfile template

Author: zakame

generate.pl

@@ -70,6 +70,13 @@ sub die_with_sample {
 EOF
 chomp $docker_slim_run_purge;
 
+my $docker_debug_run_install = <<'EOF';
+apt-get update \
+    && apt-get install -y --no-install-recommends \
+       gdb
+EOF
+chomp $docker_debug_run_install;
+
 my $config = do {
   open my $fh, '<', 'config.yml' or die "Couldn't open config";
   local $/;
@@ -152,7 +159,10 @@ sub die_with_sample {
 
     $release->{extra_flags}    ||= '';
 
-    $release->{image} = $build =~ /main/ ? 'buildpack-deps' : 'debian';
+    $release->{image} = $build =~ /(main|debug)/ ? 'buildpack-deps' : 'debian';
+
+    # leading space is important for reducing diff against non-debug Dockerfiles
+    my $debug_flags = $build =~ /debug/ ? ' -Doptimize=-g -DEBUGGING=both' : '';
 
     for my $debian_release (@{$release->{debian_release}}) {
 
@@ -162,16 +172,25 @@ sub die_with_sample {
       $output =~ s/\{\{args\}\}/$builds{$build}/mg;
 
       if ($build =~ /slim/) {
-        $output =~ s/\{\{docker_slim_run_install\}\}/$docker_slim_run_install/mg;
-        $output =~ s/\{\{docker_slim_run_purge\}\}/$docker_slim_run_purge/mg;
+        $output =~ s/\{\{docker_run_install\}\}/$docker_slim_run_install/mg;
+        $output =~ s/\{\{docker_run_purge\}\}/$docker_slim_run_purge/mg;
         $output =~ s/\{\{tag\}\}/$debian_release-slim/mg;
       }
+      elsif ($build =~ /debug/) {
+        $output =~ s/\{\{docker_run_install\}\}/$docker_debug_run_install/mg;
+        # leading space important to reduce diffs against non-debug Dockerfiles
+        $output =~ s/ \{\{debug_flags\}\}/$debug_flags/mg;
+        $output =~ s#\{\{docker_run_purge\}\}#rm -fr /var/cache/apt/* /var/lib/apt/lists/*#mg;
+        $output =~ s/\{\{tag\}\}/$debian_release/mg;
+      }
       else {
-        $output =~ s/\{\{docker_slim_run_install\}\}/true/mg;
-        $output =~ s/\{\{docker_slim_run_purge\}\}/true/mg;
+        $output =~ s/\{\{docker_run_install\}\}/true/mg;
+        $output =~ s/\{\{docker_run_purge\}\}/true/mg;
         $output =~ s/\{\{tag\}\}/$debian_release/mg;
       }
 
+      $output =~ s/ \{\{debug_flags\}\}//mg;
+
       my $dir = sprintf "%i.%03i.%03i-%s-%s", ($release->{version} =~ /(\d+)\.(\d+)\.(\d+)/), $build, $debian_release;
 
       mkdir $dir unless -d $dir;
@@ -292,7 +311,7 @@ =head1 DESCRIPTION
 {{docker_copy_perl_patch}}
 WORKDIR /usr/src/perl
 
-RUN {{docker_slim_run_install}} \
+RUN {{docker_run_install}} \
     && curl -fL {{url}} -o perl-{{version}}.tar.{{type}} \
     && echo '{{sha256}} *perl-{{version}}.tar.{{type}}' | sha256sum --strict --check - \
     && tar --strip-components=1 -xaf perl-{{version}}.tar.{{type}} -C /usr/src/perl \
@@ -301,7 +320,7 @@ =head1 DESCRIPTION
     && gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" \
     && archBits="$(dpkg-architecture --query DEB_BUILD_ARCH_BITS)" \
     && archFlag="$([ "$archBits" = '64' ] && echo '-Duse64bitall' || echo '-Duse64bitint')" \
-    && ./Configure -Darchname="$gnuArch" "$archFlag" {{args}} {{extra_flags}} -des \
+    && ./Configure -Darchname="$gnuArch" "$archFlag" {{args}} {{extra_flags}} {{debug_flags}} -des \
     && make -j$(nproc) \
     && {{test}} \
     && make install \
@@ -314,7 +333,7 @@ =head1 DESCRIPTION
     # sha256 checksum is from docker-perl team, cf https://github.com/docker-library/official-images/pull/12612#issuecomment-1158288299
     && echo '{{cpm_dist_sha256}} */usr/local/bin/cpm' | sha256sum --strict --check - \
     && chmod +x /usr/local/bin/cpm \
-    && {{docker_slim_run_purge}} \
+    && {{docker_run_purge}} \
     && rm -fr /root/.cpanm /usr/src/perl /usr/src/{{cpanm_dist_name}}* /tmp/* \
     && cpanm --version && cpm --version