This guide assumes you have a working consul server up and running and the ability to add new keys. Using the curl
command line tool add the following keys and values to 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
The confdir is where template resource configs and source templates are stored. The default confdir is /etc/confd
. Create the confdir by executing the following command:
sudo mkdir -p /etc/confd/{conf.d,templates}
You don't have to use the default confdir
location. For example you can create the confdir under your home directory. Then you tell confd to use the new confdir
via the -confdir
flag.
mkdir -p ~/confd/{conf.d,templates}
Template resources are defined in TOML config files under the confdir
conf.d directory (i.e. ~/confd/conf.d/*.toml).
Create the following template resource config and save it as ~/confd/conf.d/myconfig.toml
.
[template]
src = "myconfig.conf.tmpl"
dest = "/tmp/myconfig.conf"
keys = [
"/myapp/database/url",
"/myapp/database/user",
]
Source templates are plain old Golang text templates, and are stored under the confdir
templates directory. Create the following source template and save it as ~/confd/templates/myconfig.conf.tmpl
# This a comment
[myconfig]
database_url = {{ .myapp_database_url }}
database_user = {{ .myapp_database_user }}
confd supports two modes of operation, daemon and onetime mode. In daemon mode, confd runs in the foreground processing template resources every 5 mins by default. For this tutorial we are going to use onetime mode.
Assuming your consul server is running at http://127.0.0.1:8500 you can run the following command to process the ~/confd/conf.d/myconfig.toml
template resource:
confd -verbose -onetime -consul -consul-addr 127.0.0.1:8500 -confdir ~/confd
Output:
2013-11-03T18:00:47-08:00 confd[21294]: NOTICE Starting confd
2013-11-03T18:00:47-08:00 confd[21294]: NOTICE NOTICE Consul address set to 127.0.0.1:8500
2013-11-03T18:00:47-08:00 confd[21294]: INFO Target config /tmp/myconfig.conf out of sync
2013-11-03T18:00:47-08:00 confd[21294]: INFO Target config /tmp/myconfig.conf has been updated
The dest
config should now be in sync with the template resource configuration.
cat /tmp/myconfig.conf
Output:
# This a comment
[myconfig]
database_url = db.example.com
database_user = rob
Checkout the docs directory for more docs and usage examples.