Adds fix for msfdb issues on Ubuntu

[cgranleese-r7]

This PR resolves #12098.

ENV['PATH'] = "/usr/lib/postgresql/12/bin:#{ENV['PATH']}" has been added into the msfdb script, this sets postgresql to be included within $PATH. Prior to this change, this was something Ubuntu users had required to do manually as a fix.

The user will also have to run sudo adduser {your-user-name} postgres to add themselves as a user for the postgres group. So I plan to make some changes to the wiki to step users through setting that up. I have added a mock for the wiki below.

Before

After

Mock wiki update

I think adding the following in as a third step makes sense.

Environment

For testing I used a fresh Ubuntu VM and installed Metasploit via Git clone. Do not use the omnibus installer, as this bug is not present in that installation method as postgres comes embedded.
Once I had Metasploit cloned I just followed the wiki to get everything set-up. Once you have verified you're getting the original error.
Then add my change via vim and ensure the error is gone and ./msfdb init runs successfully.
There may be smarter ways to test this, but thought I'd mention my method.

Add the following code:

ENV['PATH'] = "/usr/lib/postgresql/12/bin:#{ENV['PATH']}"

into the following file, at line 50:

metasploit-framework/msfdb

Verification

List the steps needed to make sure this thing works

• Git clone Metasploit onto a Ubuntu VM
• Follow the wiki to get everything set-up
• Verify your getting the original error
• Add in the fix describe above in Environment section
• Verify you can run ./msfdb init without receiving any errors.

[adfoster-r7]

I think this might need some more work, as this would only work for version 12 - but not 11, or 13 etc.
Folk may have their tooling installed elsewhere too, for instance this is the location on my mac:

$ locate pg_ctl
/usr/local/Cellar/postgresql@11/11.9/bin/pg_ctl

[cgranleese-r7]

Ah, well I never thought of that. I'll have to look at this and see what I can come up with.

[adfoster-r7]

I think this problem/solution overlaps with this discussion where it's suggested not to use pg_ctl but pg_ctlcluster instead:
#11369

For context, with a fresh install on a ubuntu machine pg_ctl is not on my path, but pg_ctlcluster is:

user@ubuntu:~$ pg_ctl
pg_ctl: command not found
user@ubuntu:~$ pg_ctlcluster
Error: Usage: /usr/bin/pg_ctlcluster <version> <cluster> <action> [-- <pg_ctl options>]

Note that later on that thread there's a link to the effort/semantic differences between the current tools we're using:
#11369 (comment)

[adfoster-r7]

i.e. Adding pg_ctl onto your path works for the environment that you tested on, but it wouldn't always work for everyone

[cgranleese-r7]

Going to close this for now. After some more investigation, it's looking like this won't be as simple a fix as I first thought.