PATCH RFC use environment to signify container name for rc scripts

[Mark Goodwin <mgoodwin@xxxxxxxxxx>]

Nathan, dockerfiles have an ENV feature, which can pass an environment
variable to all future "docker run" invocations. It can also be overridden
with "docker run --env whatever=something".  So we could use this instead
of $PCP_SYSCONF_DIR/pcp.pause. An errant or stale pcp.pause file could
cause havoc (especially with QA), .. but then so could incorrect environment.

Something like $PCP_CONTAINER_NAME might prove very useful in contexts
other than rc scripts too. Thoughts?

pcp_container_env.patch
Description: Text Data