feat: write auto-detected port mappings during a deploy

During an app build, we now auto-detect ports based on the source code. This is usually http:80:5000, with Dockerfile-based deploys having their ports extracted from the docker image or Dockerfile. Additionally, we add an https:443 mapping for any detected http:80 mapping when there is an ssl certificate, and all http port mappings are transformed to https mappings for Dockerfile-based deploys.

While the ports aren't currently consumed, a future refactor will provide the ability to fallback to the new detected ports when there is no user-specified port mapping.

plugins/builder-dockerfile/builder-build

@@ -41,6 +41,10 @@ trigger-builder-dockerfile-builder-build() {
   eval "$(config_export app "$APP")"
   "$DOCKER_BIN" image build "${DOCKER_BUILD_LABEL_ARGS[@]}" $DOKKU_GLOBAL_BUILD_ARGS "${ARG_ARRAY[@]}" ${DOKKU_DOCKER_BUILD_OPTS} -t $IMAGE .
 
+  set -x
+  fn-builder-dockerfile-get-detect-port-map "$APP" "$IMAGE" "$SOURCECODE_WORK_DIR/Dockerfile"
+  plugn trigger ports-set-detected "$APP" "$(fn-builder-dockerfile-get-detect-port-map "$APP" "$IMAGE" "$SOURCECODE_WORK_DIR/Dockerfile")"
+  set +x
   plugn trigger post-build-dockerfile "$APP"
 }
 

plugins/builder-dockerfile/internal-functions

@@ -88,3 +88,47 @@ fn-builder-dockerfile-dockerfile-path() {
 
   fn-plugin-property-get-default "builder-dockerfile" "$APP" "dockerfile-path" ""
 }
+
+fn-builder-dockerfile-get-ports-from-dockerfile() {
+  declare desc="return all exposed ports from passed file path"
+  declare DOCKERFILE_PATH="$1"
+
+  suppress_output dos2unix "$DOCKERFILE_PATH"
+  local ports="$(grep -E "^EXPOSE " "$DOCKERFILE_PATH" | awk '{ print $2 }' | xargs)" || true
+  echo "$ports"
+}
+
+fn-builder-dockerfile-get-ports-from-image() {
+  declare desc="return all exposed ports from passed image name"
+  declare IMAGE="$1"
+
+  local ports="$("$DOCKER_BIN" image inspect --format "{{range $key, $value := .Config.ExposedPorts}}{{$key}} {{end}}" "$IMAGE" | xargs)" || true
+  echo "$ports"
+}
+
+fn-builder-dockerfile-get-detect-port-map() {
+  declare desc="extracts and echos a port mapping from the app"
+  declare APP="$1" IMAGE="$2" DOCKERFILE_PATH="$3"
+
+  local detected_ports=$(fn-builder-dockerfile-get-ports-from-dockerfile "$DOCKERFILE_PATH")
+
+  if [[ -z "$detected_ports" ]]; then
+    local detected_ports=$(fn-builder-dockerfile-get-ports-from-image "$IMAGE")
+  fi
+
+  if [[ -n "$detected_ports" ]]; then
+    local port_map=""
+    for p in $detected_ports; do
+      if [[ "$p" =~ .*udp.* ]]; then
+        p=${p//\/udp/}
+        port_map+="udp:$p:$p "
+      else
+        p=${p//\/tcp/}
+        port_map+="http:$p:$p "
+      fi
+    done
+    echo "$port_map" | xargs
+  else
+    echo "http:80:5000"
+  fi
+}