setup grafana prometheus node exporter on centos 7 with grafana ldap auth.

Setup Prometheus with grafana for linux monitoring

Update system to latest

$ yum update -y

Disable Selinux

Open SELinux configuration and edit the file:

vim /etc/sysconfig/selinux

Change “SELINUX=enforcing” to “SELINUX=disabled”.

Save and exit the file. Then reboot the system.

reboot
Download package from https://prometheus.io/download/

Run the following command to download package. Paste the copied URL after wget in the below command:

wget https://github.com/prometheus/prometheus/releases/download/v2.16.0/prometheus-2.16.0.linux-amd64.tar.gz

Step 4 – Configure Prometheus

Add a Prometheus user.

useradd --no-create-home --shell /bin/false prometheus

Create needed directories.

mkdir /etc/prometheus

mkdir /var/lib/prometheus

Change the owner of the above directories.

chown prometheus:prometheus /etc/prometheus

chown prometheus:prometheus /var/lib/prometheus

Now go to Prometheus downloaded location and extract it.

tar -xvzf prometheus-2.8.1.linux-amd64.tar.gz

Rename it as per your preference.

mv prometheus-2.8.1.linux-amd64 prometheuspackage

Copy “prometheus” and “promtool” binary from the “prometheuspackage” folder to “/usr/local/bin”.

cp prometheuspackage/prometheus /usr/local/bin/

cp prometheuspackage/promtool /usr/local/bin/

Change the ownership to Prometheus user.

chown prometheus:prometheus /usr/local/bin/prometheus

chown prometheus:prometheus /usr/local/bin/promtool

Copy “consoles” and “console_libraries” directories from the “prometheuspackage” to “/etc/prometheus folder”

cp -r prometheuspackage/consoles /etc/prometheus

cp -r prometheuspackage/console_libraries /etc/prometheus

Change the ownership to Prometheus user

chown -R prometheus:prometheus /etc/prometheus/consoles

chown -R prometheus:prometheus /etc/prometheus/console_libraries

Add and modify Prometheus configuration file.

Configurations should be added to the  “/etc/prometheus/prometheus.yml”

Now we will create the prometheus.yml file.

vim /etc/prometheus/prometheus.yml

Add the following configuration to the file.

global:
  scrape_interval: 10s

scrape_configs:
  - job_name: 'prometheus_master'
    scrape_interval: 5s
    static_configs:
      - targets: ['localhost:9090']

save and exit the file

Change the ownership of the file.

chown prometheus:prometheus /etc/prometheus/prometheus.yml

Configure the Prometheus Service File.

vim /etc/systemd/system/prometheus.service

Copy the following content to the file.

[Unit]
Description=Prometheus
Wants=network-online.target
After=network-online.target

[Service]
User=prometheus
Group=prometheus
Type=simple
ExecStart=/usr/local/bin/prometheus \
--config.file /etc/prometheus/prometheus.yml \
--storage.tsdb.path /var/lib/prometheus/ \
--web.console.templates=/etc/prometheus/consoles \
--web.console.libraries=/etc/prometheus/console_libraries

[Install]
WantedBy=multi-user.target

Save and the exit file.

Reload the systemd service.

systemctl daemon-reload

Start the Prometheus service.

systemctl start prometheus

Check service status.

systemctl status prometheus

Add firewall rules.

firewall-cmd --zone=public --add-port=9090/tcp --permanent

Reload firewall service.

systemctl reload firewalld

Now you can access console of prometheus

Monitor Linux Server Using Prometheus

First, you need to configure Prometheus node exporter on a Linux server.

Copy URL of the Node Exporter form the official

Paste the copied URL after wget in the following command:

wget   https://github.com/prometheus/node_exporter/releases/download/v0.18.1/node_exporter-0.18.1.linux-amd64.tar.gz

Extract the downloaded package.

tar -xvzf node_exporter-0.17.0.linux-amd64.tar.gz

Create a user for the node exporter.

useradd -rs /bin/false nodeusr

Move binary to “/usr/local/bin” from the downloaded extracted package.

mv node_exporter-0.17.0.linux-amd64/node_exporter /usr/local/bin/

Create a service file for the node exporter.

vim /etc/systemd/system/node_exporter.service

Add the following content to the file.

[Unit]
Description=Node Exporter
After=network.target

[Service]
User=nodeusr
Group=nodeusr
Type=simple
ExecStart=/usr/local/bin/node_exporter

[Install]
WantedBy=multi-user.target

Save and exit the file.

Reload the system daemon.

systemctl daemon-reload

Start node exporter service.

systemctl start node_exporter

Add a firewall rule to allow node exporter.

 firewall-cmd --zone=public --add-port=9100/tcp --permanent

Reload firewall service.

systemctl restart firewalld

Enable node exporter on system boot.

systemctl enable node_exporter

View the metrics browsing node exporter URL.

Add configured node exporter Target On Prometheus Server.

Login to Prometheus server and modify the prometheus.yml file

Edit the file:

vim /etc/prometheus/prometheus.yml

Add the following configurations under the scrape config.

 - job_name: 'node_exporter_centos'
    scrape_interval: 5s
    static_configs:
      - targets: ['10.94.10.209:9100']

Restart Prometheus service.

systemctl restart prometheus

Login to Prometheus server web interface, and check targets.

http://Prometheus-Server-IP:9090/targets

setting up grafana

Create a repo file.

vim /etc/yum.repos.d/grafana.repo

Add the following contents to file:

[grafana]
name=grafana
baseurl=https://packages.grafana.com/oss/rpm
repo_gpgcheck=1
enabled=1
gpgcheck=1
gpgkey=https://packages.grafana.com/gpg.key
sslverify=1
sslcacert=/etc/pki/tls/certs/ca-bundle.crt

Step 3 – Install Grafana

Enter the following command:

sudo yum install grafana

nstall additional font packages

Continue with following commands to install the free type and urw fonts.

yum install fontconfig

yum install freetype*

yum install urw-fonts

Step 5 – Enable Grafana Service

Check the status of the service.

systemctl status grafana-server

If service is not active, start it using the following command:

systemctl start grafana-server

Enable Grafana service on system boot

systemctl enable grafana-server.service

Step 6 – Modify Firewall

Change firewall configuration to allow Grafana port. So run following command.

firewall-cmd --zone=public --add-port=3000/tcp --permanent

Reload firewall service.

firewall-cmd --reload

Step 7 – Browse Grafana

Use the following URL to access the Grafana web interface.

http://Your Server IP or Host Name:3000/


------ setting up ldap auth

Edit vim /etc/grafana/ldap.toml  for ldap entries

Mine is like

[[servers]]
host = "192.168.1.30"
port = 389
use_ssl = false
start_tls = false
ssl_skip_verify = false
bind_dn = "uid=admin,cn=users,cn=accounts,dc=mylab,dc=local"
bind_password = 'redhat123'
search_filter = "(uid=%s)"
search_base_dns = ["cn=users,cn=accounts,dc=mylab,dc=local"]
[servers.attributes]
name = "givenName"
surname = "sn"
username = "uid"
member_of = "memberOf"
email =  "email"
[[servers.group_mappings]]
group_dn = "cn=grafanadmin,cn=groups,cn=accounts,dc=mylab,dc=local"
org_role = "Admin"
[[servers.group_mappings]]
group_dn = "cn=grafanaeditor,cn=groups,cn=accounts,dc=mylab,dc=local"
org_role = "Editor"
[[servers.group_mappings]]
group_dn = "*"
org_role = "Viewer"


Now edit  vim /etc/grafana/grafana.ini

edit like bellow

[auth.ldap]
enabled = true
config_file = /etc/grafana/ldap.toml