Cannot start Zookeeper service on CentOS7 - apache-kafka

Question

When trying to start zookeeper service I get the following
● zookeeper.service
Loaded: loaded (/etc/systemd/system/zookeeper.service; disabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Thu 2020-04-02 16:19:24 EDT; 5min ago
Process: 5201 ExecStop=/usr/local/kafka/kafka_2.13-2.4.1/bin/zookeeper-server-stop.sh (code=exited, status=1/FAILURE)
Process: 4882 ExecStart=/usr/local/kafka/kafka_2.13-2.4.1/bin/zookeeper-server-start.sh /usr/local/kafka/kafka_2.13-2.4.1/config/zookeeper.properties (code=exited, status=127)
Main PID: 4882 (code=exited, status=127)
Apr 02 16:19:24 centos.localdomain systemd[1]: Started zookeeper.service.
Apr 02 16:19:24 centos.localdomain systemd[1]: zookeeper.service: main process exited, code=exited, status=127/n/a
Apr 02 16:19:24 centos.localdomain systemd[1]: zookeeper.service: control process exited, code=exited status=1
Apr 02 16:19:24 centos.localdomain systemd[1]: Unit zookeeper.service entered failed state.
Apr 02 16:19:24 centos.localdomain systemd[1]: zookeeper.service failed.
The zookeeper.service file is configured as follows
[Unit]
Requires=network.target remote-fs.target
After=network.target remote-fs.target
[Service]
Type=simple
User=specadmin
ExecStart=/usr/local/kafka/kafka_2.13-2.4.1/bin/zookeeper-server-start.sh /usr/local/kafka/kafka_2.13-2.4.1/config/zookeeper.properties
ExecStop=/usr/local/kafka/kafka_2.13-2.4.1/bin/zookeeper-server-stop.sh
Restart=on-abnormal
[Install]
WantedBy=multi-user.target
When trying to run zookeeper manually with the same user configured in the service file everything works fine.
Please advise

Answer 1

Turns out the issue was related to the environment variables systemd uses.
Systemd uses a fixed $PATH variable and the changes that are made to the /etc/profile /etc/bashrc and the like are not applied to systemd.
Zookeeper runs java which needs to be part of the search path, but since systemd doesn't use the files where the search path is set, zookeeper start script couldn't find java.
I solved it by overriding the search path by adding Environment=PATH=... parameter in the zookeeper service file and adding all the required directories.