Riak-Debug fix

[Bob-The-Marauder]

This fix addresses https://github.com/basho/riak/issues/1037 by doing the following:

• re-adding app_epath.sh from Riak KV 2.9.7 to /usr/lib64/riak/lib on rpm builds and /usr/lib/riak/lib on deb builds from /rel/files/ via an edit to rebar.config.
• applying numerous fixes to /rel/files/riak-debug to render it compatible with KV 3.0.1.
• as /usr/sbin/riak debug actually executes /usr/lib64/riak/bin/riak-debug -s for reasons I could neither determine nor fix, I have made a work-around for this by adding a symlink from riak-debug to /usr/sbin in the post-install script for the packages.
• added a capture of directory structure for tictacaae and leveled.

The symlinks are only a temporary work-around. Once I have worked out why riak debug executes riak-debug -s and fixed it, I'll submit another pull request to update for that and remove the symlinks.

[martinsumner]

I have no objections to this - no reason why it should impact anything else.

[martincox]

@Bob-The-Marauder does riak-debug need to be symlinked to /usr/sbin? Or can it work in the same way as admin and repl via script extensions? I can't remember whether the script extensions do a node check before execution.

[martincox]

Sorry, I'm asking questions that have already been answered (I should read the comments first). I'm curious as to why it doesn't work in the same way as admin and repl still, though. I can't say as I've ever used debug tbh - do we run it against a running node (in which case the node up check should be fine)?

[martinsumner]

riaknostic is missing as a dependency (it got stripped out for 3.0). so this needs to be added back in for riak admin diag to work. Otherwise:

RPC to 'riak@127.0.0.1' failed: {'EXIT',
                                 {undef,
                                  [{riaknostic,main,[["--etc","--base"]],[]},
                                   {rpc,'-handle_call_call/6-fun-0-',5,
                                    [{file,"rpc.erl"},{line,197}]}]}}

[martinsumner]

The riaknostic repo has dialyzer/xref failures on the develop-3.0 branch so this needs some work before it can be added in.

[martinsumner]

https://github.com/basho/riaknostic/commit/723c73dc877e1d1bb4e69f893255eb7c4ba2fdf3

[martinsumner]

So there appear to be problems with the symbolic link:

martin_sumner@riak-ubuntu18:~/dbroot/riak$ sudo dpkg -i rel/pkg/packages/riak_3.0.2diag1-OTP22.3_amd64.deb 
Selecting previously unselected package riak.
(Reading database ... 202026 files and directories currently installed.)
Preparing to unpack .../riak_3.0.2diag1-OTP22.3_amd64.deb ...
Unpacking riak (3.0.2diag1-OTP22.3) ...
Setting up riak (3.0.2diag1-OTP22.3) ...
Installing new version of config file /etc/riak/riak.conf ...
ln: failed to create symbolic link '/usr/sbin/riak-debug': File exists
dpkg: error processing package riak (--install):
 installed riak package post-installation script subprocess returned error exit status 1
Processing triggers for ureadahead (0.100.0-21) ...
Processing triggers for systemd (237-3ubuntu10.42) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
Errors were encountered while processing:
 riak

[martinsumner]

I suspect dpkg -r isn't removing the link, and so when I reinstall the install package fails on hitting the link

[martinsumner]

There's more work to be done here.

I've managed to get riaknostic loading, without crashing riak. However, not it can't load the vm.args:

RPC to 'riak@127.0.0.1' failed: {'EXIT',
                                 {function_clause,
                                  [{string,substr,
                                    ["/var/lib/riak/sys.config",1,-1],
                                    [{file,"string.erl"},{line,1909}]},
                                   {riaknostic_config,load_vm_args,0,
...

Presumably the AppIndex - 1 is < 1.

This is caused by the fact that this is now a sys.config not an app.config file. I will hack away for a bit longer to see if I can make this work.

[martinsumner]

@Bob-The-Marauder Are you OK if we use this PR instead:

https://github.com/basho/riak/pull/1047

It contains modifications to this PR to get it to work on my machine. I didn't find the symlink was necessary, and made some changes so that riaknostic would load and the 'riak admin diag' would run as expected.

I can now dpkg -i ... sudo service riak start then sudo riak debug. Works on Ubuntu 18.

[martinsumner]

Replaced by #1047