From d0adb3b0ed637cd15697a69460ff8079287a39f2 Mon Sep 17 00:00:00 2001
From: Adrian Malacoda <malacoda@monarch-pass.net>
Date: Thu, 20 Aug 2020 02:37:44 -0500
Subject: [PATCH] Make default image name `image_{CONTAINER_NAME}`, and use
 `debian:stable` as fallback.

---
 README.md  |  2 +-
 otherworld | 23 ++++++++++++++++-------
 2 files changed, 17 insertions(+), 8 deletions(-)
 mode change 100644 => 100755 otherworld

diff --git a/README.md b/README.md
index 8d8bb84..0084c4a 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ These are arguments that go between `otherworld` and the command.
 Name to assign to container (default: `otherworld_$USER`)
 
 ### --image=<image>
-Image to create the container with (default: `debian:stable`)
+Image to create the container with (default: `image_$CONTAINER_NAME`, or `debian:stable` if that image does not exist)
 
 ### --sudo
 Runs command as root, instead of current user.
diff --git a/otherworld b/otherworld
old mode 100644
new mode 100755
index eb7f0ec..4114ff7
--- a/otherworld
+++ b/otherworld
@@ -7,7 +7,7 @@ import sys
 import json
 
 CONTAINER_NAME = "otherworld"
-IMAGE_NAME = "debian:stable"
+DEFAULT_IMAGE_NAME = "debian:stable"
 
 def create_x11_mapping ():
     home = os.environ["HOME"]
@@ -110,7 +110,7 @@ def expand_user_volumes (volumes):
 
 user = os.environ["USER"]
 uid = int(check_output(["id", "-u"]).strip())
-image_name = os.environ.get("OW_IMAGE", IMAGE_NAME)
+image_name = os.environ.get("OW_IMAGE", None)
 container_name = os.environ.get("OW_CONTAINER", f"{CONTAINER_NAME}_{user}")
 build_path = None
 
@@ -144,9 +144,6 @@ while len(command) > 0:
     elif arg.startswith("--container="):
         container_name = arg[len("--container="):]
         command = command[1:]
-    elif arg.startswith("--image"):
-        image_name = get_generated_image_name(container_name)
-        command = command[1:]
     elif arg.startswith("--image="):
         image_name = arg[len("--image="):]
         command = command[1:]
@@ -177,8 +174,20 @@ except Exception:
     build_path = resolve_build_path(build_path)
     if build_path is not None:
         image_name = docker_build(build_path, ["--pull"] if pull else [], get_generated_image_name(container_name))
-    elif pull:
-        docker_pull(image_name)
+    else:
+        if image_name is None:
+            image_name = get_generated_image_name(container_name)
+            try:
+                docker_inspect(image_name)
+                if not quiet:
+                    print(f">> Using default otherworld image {image_name}")
+            except Exception:
+                if not quiet:
+                    print(f">> Default otherworld image {image_name} not found, falling back to {DEFAULT_IMAGE_NAME}")
+                image_name = DEFAULT_IMAGE_NAME
+
+        if pull:
+            docker_pull(image_name)
 
     if not quiet:
         print(f">> Creating container: {container_name} (using image: {image_name})")