Hashicorp Nomad to set up an OSTicket Helpdesk - Part I
I now have a Docker-Compose File that allows me to provision an instance of the OSTicket Helpdesk with a MariaDB backend. Now I need to get this into my Nomad/Consul cluster.
Data Persistence
The docker-compose.yml adds a volumen mount to the MariaDB container to make sure that the generated database is not destroyed when the container is shut down.
volumes:
- /opt/osticket/db:/var/lib/mysql
In Nomad we will have to define this volume mount in the Nomad client configuration.
Client Configuration
First we need to create a volume that allows us to persist the data that MariaDB is going to generate. Add the following configs in your client.hcl file [Plugin Stanza | Host Volume Stanza]:
nano /etc/nomad.d/client.hcl
client {
enabled = true
servers = ["myhost:port"]
host_volume "letsencrypt" {
path = "/etc/letsencrypt"
read_only = false
}
host_volume "osticket_db" {
path = "/opt/osticket/db"
read_only = false
}
}
# Docker Configuration
plugin "docker" {
volumes {
enabled = true
selinuxlabel = "z"
}
allow_privileged = false
allow_caps = ["chown", "net_raw"]
}
This client already uses a volume to allow containers access to the Let's Encrypt generated TLS certificates. I can add the database volume below. And make sure that the directory you define here as a volume does exist mkdir -p /opt/osticket/db.
Restart the service service nomad restart and verify that the volume was picked up:
Job Specification
And then in the job specifications, inside the Group Stanza define the volume:
volume "osticket_db" {
type = "host"
read_only = false
source = "osticket_db"
}
and then finally add following in the Task Stanza use the defined volume:
volume_mount {
volume = "osticket_db"
destination = "/var/lib/mysql" #<-- in the container
read_only = false
}
The OSTicket frontend does not need any persistence or volume mounts in general since I already added all customized files to the docker file itself.
Environment Variables
The only thing missing now are the environment variables that allow our two containers - frontend and database - to connect. These have to be placed inside the corresponding Task Stanza:
MariaDB
env {
MYSQL_ROOT_PASSWORD = "secret"
MYSQL_USER = "osticket"
MYSQL_PASSWORD = "secret"
MYSQL_DATABASE = "osticket"
CONTAINER_NAME = "osticket-db"
}
OSTicket
env {
CONTAINER_NAME = "osticket"
MYSQL_USER = "osticket"
MYSQL_HOST = "osticket-db"
MYSQL_PASSWORD = "secret"
MYSQL_DATABASE = "osticket"
}
Run the Job File
nomad plan osticket.tf
+ Job: "osticket"
+ Task Group: "docker" (1 create)
+ Task: "osticket-container" (forces create)
+ Task: "osticket-db-container" (forces create)
Scheduler dry-run:
- All tasks successfully allocated.
Job Modify Index: 0
To submit the job with version verification run:
nomad job run -check-index 0 osticket.tf
Running the job looks good - the ERROR logs remain empty:
After a little tweaking I now have the following Nomad job file that brings up both services:
But when I bring the services up I am getting the error message that OSTicket cannot find my database. So eventually the deployment fails because the frontend never reaches a healthy state. So this is what I have to look into next:
Complete Job File (Part I)
job "osticket" {
datacenters = ["mydatacenter"]
type = "service"
group "osticket-db" {
count = 1
network {
mode = "host"
port "tcp" {
static = 3306
to = 3306
}
}
update {
max_parallel = 1
min_healthy_time = "10s"
healthy_deadline = "5m"
progress_deadline = "10m"
auto_revert = true
auto_promote = true
canary = 1
}
volume "osticket_db" {
type = "host"
read_only = false
source = "osticket_db"
}
restart {
attempts = 10
interval = "5m"
delay = "25s"
mode = "delay"
}
task "osticket-db-container" {
driver = "docker"
config {
image = "mariadb:latest"
ports = ["tcp"]
network_mode = "host"
force_pull = false
}
volume_mount {
volume = "osticket_db"
destination = "/var/lib/mysql" #<-- in the container
read_only = false
}
env {
MYSQL_ROOT_PASSWORD = "secret"
MYSQL_USER = "osticket"
MYSQL_PASSWORD = "secret"
MYSQL_DATABASE = "osticket"
# CONTAINER_NAME = "osticket-db"
}
}
}
group "osticket-frontend" {
count = 1
network {
mode = "host"
port "http" {
static = 8080
to = 80
}
}
update {
max_parallel = 1
min_healthy_time = "10s"
healthy_deadline = "5m"
progress_deadline = "10m"
auto_revert = true
auto_promote = true
canary = 1
}
service {
name = "osticket-frontend"
port = "http"
tags = [
"frontend"
]
check {
name = "HTTP Health"
path = "/"
type = "http"
protocol = "http"
interval = "10s"
timeout = "2s"
}
}
task "osticket-container" {
driver = "docker"
config {
image = "my.gitlab.com:12345/server/osticket-docker:latest"
ports = ["http"]
network_mode = "host"
force_pull = false
auth {
username = "myuser"
password = "secret"
}
}
env {
CONTAINER_NAME = "osticket"
MYSQL_USER = "osticket"
MYSQL_HOST = "osticket-db"
MYSQL_PASSWORD = "secret"
MYSQL_DATABASE = "osticket"
}
}
}
}