post-install messages still show up if the package fails to install

[stevendanna]

From @smith in chef/opscode-omnibus#427:

Tried this:

root@private-chef:/opt/opscode/sv/opscode-webui# dpkg -i /tmp/cache/private-chef_11.2.99+20140830193320.git.2.dd76a61-1_amd64.deb
(Reading database ... 136994 files and directories currently installed.)
Preparing to replace private-chef 11.1.5+20140725034804.git.249.b22037f-1 (using .../private-chef_11.2.99+20140830193320.git.2.dd76a61
-1_amd64.deb) ...
Unpacking replacement private-chef ...
dpkg: error processing /tmp/cache/private-chef_11.2.99+20140830193320.git.2.dd76a61-1_amd64.deb (--install):
 unable to make backup link of `./opt/opscode/embedded/cookbooks/private-chef/providers/pg_cluster.rb' before installing new version:
Operation not permitted
dpkg-deb: subprocess paste killed by signal (Broken pipe)
You have upgraded Private Chef!

The next step in the upgrade process is to run:

private-chef-ctl upgrade

Then, to remove configuration files, logs, directories,
users, etc. that were used by internal services that
have been removed from this version of Private Chef,
please run:

private-chef-ctl cleanup

(Add the '--no-op' option to see what would be removed by
this command)
Errors were encountered while processing:
 /tmp/cache/private-chef_11.2.99+20140830193320.git.2.dd76a61-1_amd64.deb

Notice that the install failed due to some permissions issues with dev-vm mounting, but the messages telling me to run upgrade/cleanup were still printed. These should only show up on a successful package install. On Ubuntu 10.04.

[stevendanna]

I've reproduced this bug in the following way:

# chattr +ia /opt/opscode/embedded/cookbooks/private-chef/providers/pg_cluster.rb
#  ... 100617 files and directories currently installed.)
Preparing to unpack .../chef-server-core_12.0.8-1_amd64.deb ...
Unpacking chef-server-core (12.0.8-1) over (12.0.8-1) ...
dpkg: error processing archive /vagrant/chef-server-core_12.0.8-1_amd64.deb (--install):
 unable to make backup link of `./opt/opscode/embedded/cookbooks/private-chef/providers/pg_cluster.rb' before installing new version: Operation not permitted
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
chown: changing ownership of ‘/opt/opscode/embedded/cookbooks/private-chef/providers/pg_cluster.rb’: Operation not permitted
You have upgraded Chef Server!

The next step in the upgrade process is to run:

chef-server-ctl upgrade

Then, to remove configuration files, logs, directories,
users, etc. that were used by internal services that
have been removed from this version of Chef Server,
please run:

chef-server-ctl cleanup

(Add the '--no-op' option to see what would be removed by
this command)
Errors were encountered while processing:
 /vagrant/chef-server-core_12.0.8-1_amd64.deb

When an upgrade fails dpkg has complicated rules for which scripts it runs and with what arguments: https://www.debian.org/doc/debian-policy/ch-maintainerscripts.html

My hunch is that the previous copy of the postinst script (the one being upgraded over) is being called with arguments indicating the upgrade failed, but we don't do anything with them.

[tas50]

I don't believe we can control how the OS displays post install messages. Closing this one out.