Share a container among different clusters

[rashtao]

I want to link the same container to different clusters (eg. to have a shared dbms among all the clusters).
Is it possible? How can I do that?

This is my current configuration:

containers:
  a:
    image:        a
    dependencies:
      - b
  b:
    image:        b
    dependencies:
      - db
  db:
    image:        db

clusters:
  c1:      ["a", "b"]
  c2:      ["a", "b"]

groups:
  c1:
    options:
      env:        ["CLUSTER_NAME=c1"]
    containers:
  c2:
    options:
      env:        ["CLUSTER_NAME=c2"]
    containers:

and I would like to have only one container for db linked both from b.c1 and b.c2. But if I try to create and run the clusters:

# decking build all
# decking create c1
# decking create c2
# decking start c1
# decking start c2

I get 6 containers running:

• a.c1, b.c1, db.c1,
• a.c2, b.c2, db.c2

[guillaumelecerf]

I think this commit may do the job:
https://github.com/guillaumelecerf/decking/commit/4ace57ed3937b995d577736707430533d3b13669