feat: added prefix/suffix support for GENERIC_PACKS (#1321)

For #1315

tests/setuponlytests/generic-packs-prefix/docker-compose.yml

@@ -0,0 +1,14 @@
+version: "3"
+
+services:
+  mc:
+    image: ${IMAGE_TO_TEST:-itzg/minecraft-server}
+    environment:
+      EULA: "true"
+      SETUP_ONLY: "TRUE"
+      GENERIC_PACKS: testing
+      GENERIC_PACKS_PREFIX: /packs/
+      GENERIC_PACKS_SUFFIX: .zip
+    volumes:
+      - ./packs:/packs
+      - ./data:/data

tests/setuponlytests/generic-packs-prefix/verify.sh

@@ -0,0 +1 @@
+mc-image-helper assert fileExists one.txt mods/two.txt

tests/setuponlytests/generic-packs/docker-compose.yml

@@ -1,12 +1,18 @@
 version: "3"
 
 services:
+  web:
+    image: nginx
+    volumes:
+      - ./web:/usr/share/nginx/html
   mc:
+    depends_on:
+      - web
     image: ${IMAGE_TO_TEST:-itzg/minecraft-server}
     environment:
       EULA: "true"
       SETUP_ONLY: "TRUE"
-      GENERIC_PACKS: https://github.com/itzg/mc-image-helper/releases/download/v1.9.5/mc-image-helper-1.9.5.zip,/packs/testing.zip
+      GENERIC_PACKS: http://web/configs.zip,/packs/testing.zip
     volumes:
       - ./packs:/packs
       - ./data:/data

tests/setuponlytests/generic-packs/verify.sh

@@ -1 +1,2 @@
-mc-image-helper assert fileExists one.txt mods/two.txt
+mc-image-helper assert fileExists one.txt mods/two.txt
+mc-image-helper assert fileExists one.txt config/opt.yml