software/theia: Simplify embedded SR options

Remove existing "embedded instance" options:
- `embedded-sr`
- `embedded-sr-type`
- `embedded-instance-parameters`

Instead introduce `one-time-embedded-sr`:
- Supply the given SR, but only the first time.
- Create a supply/request script for the user.

This parameter is only taken into account the first time it's used.
It __doesn't__ automatically request an instance. It doesn't call
the request script created for the user.

software/theia/buildout.hash.cfg

@@ -15,11 +15,11 @@
 
 [instance-theia]
 _update_hash_filename_ = instance-theia.cfg.jinja.in
-md5sum = 898ada9e42d8aafae571eba230708cc3
+md5sum = cb1ffe2ca26092db227e960ec58bb85e
 
 [instance]
 _update_hash_filename_ = instance.cfg.in
-md5sum = 313eb380fdd2d0882f329af4a1157259
+md5sum = 450c89616e1f8c445f6f09029c2b9c6e
 
 [instance-import]
 _update_hash_filename_ = instance-import.cfg.jinja.in

software/theia/instance-input-schema.json

@@ -15,19 +15,9 @@
       ],
       "default": "running"
     },
-    "embedded-sr": {
-      "title": "Embedded Software URL",
-      "description": "Optional URL of a software to be embedded",
-      "type": "string"
-    },
-    "embedded-sr-type": {
-      "title": "Embedded Software Type",
-      "description": "Type of the optional embedded software",
-      "type": "string"
-    },
-    "embedded-instance-parameters": {
-      "title": "Embedded Instance Parameters",
-      "description": "Parameters for the embedded instance, as a JSON dict",
+    "one-time-embedded-sr": {
+      "title": "One-Time-Only Embedded Software URL",
+      "description": "Optional software URL of an instance to be supplied and requested in embedded slapos. Only applies the first this option is used.",
       "type": "string"
     },
     "frontend-guid": {

software/theia/instance.cfg.in

@@ -31,6 +31,7 @@ pull-backup = template-pull-backup:rendered
 recipe = slapos.recipe.template:jinja2
 url = ${instance-theia:output}
 output = $${buildout:directory}/instance-theia.cfg
+extensions = jinja2.ext.do
 context =
   jsonkey default_parameter_dict :default-parameters
   key parameter_dict slap-configuration:configuration
@@ -38,14 +39,12 @@ context =
   key partition_root_path buildout:directory
   key ipv6_random slap-configuration:ipv6-random
   key ipv4_random slap-configuration:ipv4-random
-  import os_module os
-  import hashlib_module hashlib
+  import os os
+  import json json
 default-parameters =
   {
     "autorun": "running",
-    "embedded-sr": null,
-    "embedded-sr-type": null,
-    "embedded-instance-parameters": null,
+    "one-time-embedded-sr": null,
     "frontend-name": "Theia Frontend",
     "frontend-sr": "$${:frontend-sr}",
     "frontend-sr-type": "RootSoftwareInstance",