Install REST Application

To install a REST API to interact with Metron, complete the following steps:

Create a file /etc/yum.repos.d/HCP.repo containing the following information. Make sure the information matches your installation, including the version number, etc.

#VERSION_NUMBER=1.1.0.0-71
[HCP-1.1.0.0-71]
name=HCP Version - HCP-1.1.0.0-71
baseurl=http://s3.amazonaws.com/dev.hortonworks.com/HCP/centos6/1.x/BUILDS/1.1.0.0-71
gpgcheck=1
gpgkey=http://s3.amazonaws.com/dev.hortonworks.com/HCP/centos6/1.x/BUILDS/1.1.0.0-71/RPM-GPG-KEY/RPM-GPG-KEY-Jenkins
enabled=1
priority=1

Install the REST package:

CentOS 6 and 7
```
yum install metron-rest
```
Ubuntu
```
apt-get install metron-rest
```

Connect to MySQL and create a Metron REST database:

mysql -uroot -p
CREATE DATABASE IF NOT EXISTS metronrest;

Create a Metron user in MySQL with a password, then apply database access permission to the Metron user:

CREATE USER 'metron'@'REST_HOST' IDENTIFIED BY 'Myp@ssw0rd';
GRANT ALL PRIVILEGES ON metronrest.* TO 'metron'@'REST_HOST';

Create user and authorities tables:

use metronrest;
create table if not exists users(
  username varchar(50) not null primary key,
  password varchar(50) not null,
  enabled boolean not null
);
create table authorities (
  username varchar(50) not null,
  authority varchar(50) not null,
  constraint fk_authorities_users foreign key(username) references users(username)
);
create unique index ix_auth_username on authorities (username,authority);

Add one or more users to the REST application:

use metronrest;
insert into users (username, password, enabled) values ('your_username','your_password',1);
insert into authorities (username, authority) values ('your_username', 'ROLE_USER');

Exit MySQL:
```
quit
```

Create the $METRON_HOME/config/application.yml file containing the following:

server:
  port: 8082              
              
spring:
  datasource:
      driverClassName: org.h2.Driver
      url: jdbc:h2:file:./metrondb
      username: root
      password: root
      platform: h2  
  jpa:
    hibernate:
      ddl-auto: update

zookeeper:
  url:  ${ZOOKEEPER}
  
kafka:
  broker:
    url: ${BROKERLIST}
    
hdfs:
  namenode:
    url: ${HDFS_URL}
    
grok:
  path:
    temp: ./patterns/temp
    default: /apps/metron/patterns
    
storm:
  ui:
    url:   ${STORM_REST_URL}
  parser:
    script.path: ${METRON_HOME}/bin/start_parser_topology.sh
  enrichment:
    script.path: ${METRON_HOME}/bin/start_enrichment_topology.sh
  indexing:
    script.path: ${METRON_HOME}/bin/start_elasticsearch_topology.sh

Replace the H2 connection information in the $METRON_HOME/config/application.yml file with MySQL connection information:

spring:
  datasource:
        driverClassName: com.mysql.jdbc.Driver
        url: jdbc:mysql://mysql_host:3306/metronrest
        username: metron_rest_user
        password: metron_rest_password

Install the appropriate MySQL client library for your version of MySQL. For example:

cd $METRON_HOME/lib
wget https://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-java-5.1.41.tar.gz
tar xf mysql-connector-java-5.1.41.tar.gz

Start the REST application:
```
nohup java -Dloader.path=$METRON_HOME/lib/mysql-connector-java-5.1.41/mysql-connector-java-5.1.41-bin.jar -jar $METRON_HOME/lib/metron-rest-$METRON_VERSION.jar --spring.config.location=$METRON_HOME/config/application.yml > rest-api.log 2>&1 &
```
where:
nohup
No hangup. The nohup command is a POSIX command to ignore the HUP (hangup) signal. The HUP signal is used, by convention, by a terminal to warn dependent processes of logout. Output that would normally go to the terminal goes to a file called nohup.out if it has not already been redirected.
2>&1
Redirect all stderr output to stdout. File descriptor 1 is stdout, file descriptor 2 is stderr. The ampersand instructs the shell to interpret the 1 as a file descriptor instead of as a file named "1".
&
Background the process

To add additional users:

use metronrest;
insert into users (username, password, enabled) values ('your_username','your_password',1);
insert into authorities (username, authority) values ('your_username', 'ROLE_USER');
commit;

In a cluster with Kerberos enabled, update the security settings in /etc/sysconfig/metron.

METRON_SPRING_PROFILES_ACTIVE="vagrant,dev"
METRON_JVMFLAGS="Djava.security.auth.login.config=$METRON_HOME/client_jaas.confg"
METRON_SPRING_OPTIONS="--kerberos.enables=true"

Make sure you can access the Swagger UI at http://host:port/swagger-ui.html#/.
The exposed REST endpoints can be accessed with the Swagger UI at http://host:port/swagger-ui.html#/. The default port is 8082 but can be changed in the $METRON_HOME/config/application.yml file by setting "server.port" to the desired port.

​Install REST Application

Install REST Application