Can not start elasticsearch as a service in ubuntu 16.04

Question

I have recently upgraded my machine from Ubuntu 14.04 to 16.04. I am facing problem of using the elasticsearch as a service. I installed elasticsearch using:

sudo apt-get install elasticsearch

Now sudo service elasticsearch status command shows me this result:

elasticsearch.service - LSB: Starts elasticsearch
   Loaded: loaded (/etc/init.d/elasticsearch; bad; vendor preset: enabled)
   Active: active (exited) since Sat 2016-07-30 18:28:13 BDT; 1h 19min ago
     Docs: man:systemd-sysv-generator(8)
 Main PID: 7988 (code=exited, status=1/FAILURE)
   CGroup: /system.slice/elasticsearch.service

Jul 30 18:28:13 dimik elasticsearch[10266]: [warning] /etc/init.d/elasticsearch: No java runtime was found
Jul 30 18:28:13 dimik systemd[1]: Started LSB: Starts elasticsearch.
Jul 30 18:28:46 dimik systemd[1]: Started LSB: Starts elasticsearch.
Jul 30 18:35:30 dimik systemd[1]: Started LSB: Starts elasticsearch.
Jul 30 19:04:36 dimik systemd[1]: Started A search engine.
Jul 30 19:07:48 dimik systemd[1]: Started A search engine.
Jul 30 19:27:01 dimik systemd[1]: Started A search engine.
Jul 30 19:27:51 dimik systemd[1]: Started A search engine.
Jul 30 19:28:54 dimik systemd[1]: Started A search engine.
Jul 30 19:29:18 dimik systemd[1]: Started LSB: Starts elasticsearch.

Although Java is installed in my machine and I can start the server using this command.

sudo /usr/share/elasticsearch/bin/elasticsearch

I am kind of stuck here. Any help will be appreciated.

Edit

After setting up JAVA_HOME for root the error:

elasticsearch.service - LSB: Starts elasticsearch
   Loaded: loaded (/etc/init.d/elasticsearch; bad; vendor preset: enabled)
   Active: active (exited) since Sat 2016-07-30 18:28:13 BDT; 3h 32min ago
     Docs: man:systemd-sysv-generator(8)
 Main PID: 7988 (code=exited, status=1/FAILURE)
   CGroup: /system.slice/elasticsearch.service

Jul 30 18:35:30 dimik systemd[1]: Started LSB: Starts elasticsearch.
Jul 30 19:04:36 dimik systemd[1]: Started A search engine.
Jul 30 19:07:48 dimik systemd[1]: Started A search engine.
Jul 30 19:27:01 dimik systemd[1]: Started A search engine.
Jul 30 19:27:51 dimik systemd[1]: Started A search engine.
Jul 30 19:28:54 dimik systemd[1]: Started A search engine.
Jul 30 19:29:18 dimik systemd[1]: Started LSB: Starts elasticsearch.
Jul 30 20:02:07 dimik systemd[1]: Started LSB: Starts elasticsearch.
Jul 30 20:20:21 dimik systemd[1]: Started LSB: Starts elasticsearch.
Jul 30 21:59:21 dimik systemd[1]: Started LSB: Starts elasticsearch.

Answer 1

I found the solution for this issue. The solution comes from this discussion thread- Can’t start elasticsearch with Ubuntu 16.04 on elastic's website.

It seems that to get Elasticsearch to run on 16.04 you have to set START_DAEMON to true on /etc/default/elasticsearch. It comes commented out by default, and uncommenting it makes Elasticsearch start again just fine.

Be sure to use systemctl restart instead of just start because the service is started right after installation, and apparently there's some socket/pidfile/something that systemd keeps that must be released before being able to start the service again.