Deployment ( digression from: Longstanding issues: ...)

[Mikael Karlsson]

torsdag 23 februari 2006 10:04 skrev Ulf Wiger (AL/EAB):
> Mikael Karlsson wrote:
> > The problem with deployment on Erlang, as I see
> > it, is that it is not possible to add new
> > applications to releases, and that they all have
> > to go into the erlang root library.
>
> This is not true. You can provide several roots
> to the systools script, and you can have your own
> "releases" directory wherever you want.
> ...
Oh dear, I better read the .. manual. I do not know what is worst,
coming with false statements or having been unaware of this all
theese years.

I am still a bit lost though, with the concept of one boot file per 
application in the priv dir.

My use case - scenario is this.
Precondition:
- a distributed erlang environment on several machines.
- Erlang OTP installed in /usr/local/lib/erlang.
- I "third party" application installed in /usr/local/yaws ( .erlang is 
  used to add  this to the path)
- Starting erlang from an ordinary user /home/usr
- export ERL_BASE=/home/usr/erl_base 
- All new apps to go into $ERL_BASE/lib, on all nodes.

Can I, for all nodes in one go:
1. Make a relase package with one new application app1-vsn11 that goes into
$ERL_BASE/lib
2. Make a release upgrade, upgrading to app1-vsn12 and add a new app2-vsn21
3. Make a release upgrade, adding app3-vsn31 and keep the old ones as is.
4. Make a release upgrade removing app2-vsn21, keeping everything else.

And 1-4 without having to deal with all OTP application versions.

Cheers
Mikael