quick-start-guide.md

Quick Start Guide

Before we begin be sure to download and install confd.

Select a backend

confd supports the following backends:

• etcd
• consul
• environment variables

Add keys

This guide assumes you have a working etcd, or consul server up and running and the ability to add new keys.

etcd

etcdctl set /myapp/database/url db.example.com
etcdctl set /myapp/database/user rob

consul

curl -X PUT -d 'db.example.com' http://localhost:8500/v1/kv/myapp/database/url
curl -X PUT -d 'rob' http://localhost:8500/v1/kv/myapp/database/user

environment variables

export MYAPP_DATABASE_URL=db.example.com
export MYAPP_DATABASE_USER=rob

Create the confdir

The confdir is where template resource configs and source templates are stored.

sudo mkdir -p /etc/confd/{conf.d,templates}

Create a template resource config

Template resources are defined in TOML config files under the confdir.

/etc/confd/conf.d/myconfig.toml

[template]
src = "myconfig.conf.tmpl"
dest = "/tmp/myconfig.conf"
keys = [
    "/myapp/database/url",
    "/myapp/database/user",
]

Create the source template

Source templates are Golang text templates.

/etc/confd/templates/myconfig.conf.tmpl

[myconfig]
database_url = {{getv "/myapp/database/url"}}
database_user = {{getv "/myapp/database/user"}}

Process the template

confd supports two modes of operation daemon and onetime. In daemon mode confd polls a backend for changes and updates destination configuration files if necessary.

etcd

confd -onetime -backend etcd -node 127.0.0.1:4001

consul

confd -onetime -backend consul -node 127.0.0.1:8500

env

confd -onetime -backend env

Output:

2014-07-08T20:38:36-07:00 confd[16252]: WARNING Skipping confd config file.
2014-07-08T20:38:36-07:00 confd[16252]: INFO Target config /tmp/myconfig.conf out of sync
2014-07-08T20:38:36-07:00 confd[16252]: INFO Target config /tmp/myconfig.conf has been updated

The dest configuration file should now be in sync.

cat /tmp/myconfig.conf

Output:

# This a comment
[myconfig]
database_url = db.example.com
database_user = rob

Advanced Example

In this example we will use confd to manage two nginx config files using a single template.

Add keys

etcd

etcdctl set /myapp/subdomain myapp
etcdctl set /myapp/upstream/app2 "10.0.1.100:80"
etcdctl set /myapp/upstream/app1 "10.0.1.101:80"
etcdctl set /yourapp/subdomain yourapp
etcdctl set /yourapp/upstream/app2 "10.0.1.102:80"
etcdctl set /yourapp/upstream/app1 "10.0.1.103:80"

consul

curl -X PUT -d 'myapp' http://localhost:8500/v1/kv/myapp/subdomain
curl -X PUT -d '10.0.1.100:80' http://localhost:8500/v1/kv/myapp/upstream/app1
curl -X PUT -d '10.0.1.101:80' http://localhost:8500/v1/kv/myapp/upstream/app2
curl -X PUT -d 'yourapp' http://localhost:8500/v1/kv/yourapp/subdomain
curl -X PUT -d '10.0.1.102:80' http://localhost:8500/v1/kv/yourapp/upstream/app1
curl -X PUT -d '10.0.1.103:80' http://localhost:8500/v1/kv/yourapp/upstream/app2

Create template resources

/etc/confd/conf.d/myapp-nginx.toml

[template]
prefix = "/myapp"
src = "nginx.tmpl"
dest = "/tmp/myapp.conf"
owner = "nginx"
mode = "0644"
keys = [
  "/subdomain",
  "/upstream",
]
check_cmd = "/usr/sbin/nginx -t -c {{.src}}"
reload_cmd = "/usr/sbin/service nginx reload"

/etc/confd/conf.d/yourapp-nginx.toml

[template]
prefix = "/yourapp"
src = "nginx.tmpl"
dest = "/tmp/yourapp.conf"
owner = "nginx"
mode = "0644"
keys = [
  "/subdomain",
  "/upstream",
]
check_cmd = "/usr/sbin/nginx -t -c {{.src}}"
reload_cmd = "/usr/sbin/service nginx reload"

Create the source template

/etc/confd/templates/nginx.tmpl

upstream {{getv "/subdomain"}} {
{{range getvs "/upstream/*"}}
    server {{.}};
{{end}}
}

server {
    server_name  {{getv "/subdomain"}}.example.com;
    location / {
        proxy_pass        http://{{getv "/subdomain"}};
        proxy_redirect    off;
        proxy_set_header  Host             $host;
        proxy_set_header  X-Real-IP        $remote_addr;
        proxy_set_header  X-Forwarded-For  $proxy_add_x_forwarded_for;
   }
}