After several attempts and several uninstalls, this problem keeps on persisting with installation -- it appears that the installation is missing some core files from the installation source
$ sudo apt-get update && sudo apt-get install logstash
Hit:1 http://us-west-1.ec2.archive.ubuntu.com/ubuntu xenial InRelease
Hit:2 http://us-west-1.ec2.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:3 http://us-west-1.ec2.archive.ubuntu.com/ubuntu xenial-backports InRelease
Hit:4 http://security.ubuntu.com/ubuntu xenial-security InRelease
Hit:5 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease
Ign:6 https://artifacts.elastic.co/packages/6.x/apt stable InRelease
Hit:7 https://artifacts.elastic.co/packages/6.x/apt stable Release
Reading package lists... Done
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/elastic-6.x.list:1 and /etc/apt/sources.list.d/elastic-6.x.list:2
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/elastic-6.x.list:1 and /etc/apt/sources.list.d/elastic-6.x.list:2
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/elastic-6.x.list:1 and /etc/apt/sources.list.d/elastic-6.x.list:2
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/elastic-6.x.list:1 and /etc/apt/sources.list.d/elastic-6.x.list:2
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/elastic-6.x.list:1 and /etc/apt/sources.list.d/elastic-6.x.list:2
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/elastic-6.x.list:1 and /etc/apt/sources.list.d/elastic-6.x.list:2
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/elastic-6.x.list:1 and /etc/apt/sources.list.d/elastic-6.x.list:2
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/elastic-6.x.list:1 and /etc/apt/sources.list.d/elastic-6.x.list:2
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
logstash
0 upgraded, 1 newly installed, 0 to remove and 1 not upgraded.
Need to get 0 B/149 MB of archives.
After this operation, 249 MB of additional disk space will be used.
Selecting previously unselected package logstash.
(Reading database ... 76952 files and directories currently installed.)
Preparing to unpack .../logstash_1%3a6.3.0-1_all.deb ...
Unpacking logstash (1:6.3.0-1) ...
Setting up logstash (1:6.3.0-1) ...
sed: can't read /etc/logstash/logstash.yml: No such file or directory
/etc/logstash/startup.options is not a file path
To manually specify a startup style, put the path to startup.options as the
first argument, followed by the startup style (sysv, upstart, systemd)
chmod: cannot access '/etc/logstash/startup.options': No such file or directory
$