Difference between revisions of "HashiCorp/Consul"
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</source> | </source> | ||
= Define a service = | |||
Consul loads all configuration files in the configuration directory, so a common convention on Unix systems is to name the directory something like <code>/etc/consul.d</code> | |||
<source lang=bash> | |||
mkdir ./consul.d | |||
echo '{"service": {"name": "web", "tags": ["rails"], "port": 80}}' \ | |||
> ./consul.d/web.json | |||
consul agent -dev -config-dir=./consul.d | |||
</source> | |||
Query service | |||
<source lang=bash> | |||
dig @127.0.0.1 -p 8600 web.service.consul | |||
dig @127.0.0.1 -p 8600 web.service.consul SRV | |||
curl http://localhost:8500/v1/catalog/service/web | |||
curl 'http://localhost:8500/v1/health/service/web?passing' | |||
</source> | |||
= References = | = References = | ||
*[https://blog.fraq.io/tech/consul-template/ A practical and simple consul-template example] Tutorial with docker restart based on a template change | *[https://blog.fraq.io/tech/consul-template/ A practical and simple consul-template example] Tutorial with docker restart based on a template change | ||
Revision as of 08:34, 12 March 2019
Install
wget https://releases.hashicorp.com/consul/1.4.3/consul_1.4.3_linux_amd64.zip unzip consul_1.4.3_linux_amd64.zip sudo mv consul /usr/bin
Run consul agent
You need run at least one consul server 3-5 are recommended. All other agents do run in a client mode, it's very light weight process that :
- register services
- check healthchecks
- forward queries to servers
- agent needs to run on every node that is a part of a cluster
Run consul in dev mode where single server is also acting as a client:
consul agent -dev -node <consul_hostname> # -node is optional as by default hostname is used, but for OSX with period in it will case problems with dns queries
Consul will start listenig on following ports
Netid State Local Address:Port udp UNCONN 127.0.0.1:8301 udp UNCONN 127.0.0.1:8302 udp UNCONN 127.0.0.1:8600 tcp LISTEN 127.0.0.1:8300 tcp LISTEN 127.0.0.1:8301 tcp LISTEN 127.0.0.1:8302 tcp LISTEN 127.0.0.1:8500 tcp LISTEN 127.0.0.1:8600
Basic cluster checks and calls
consul members -details Node Address Status Type Build Protocol DC Segment u18gui-1 127.0.0.1:8301 alive server 1.4.3 2 dc1 <all> # API call curl localhost:8500/v1/catalog/nodes # DNS interface, using dns lookups, consuls listenig on udp/tcp:8600 port dig @127.0.0.1 -p 8600 <consul_hostname>.node.consul
Define a service
Consul loads all configuration files in the configuration directory, so a common convention on Unix systems is to name the directory something like /etc/consul.d
mkdir ./consul.d
echo '{"service": {"name": "web", "tags": ["rails"], "port": 80}}' \
> ./consul.d/web.json
consul agent -dev -config-dir=./consul.d
Query service
dig @127.0.0.1 -p 8600 web.service.consul dig @127.0.0.1 -p 8600 web.service.consul SRV curl http://localhost:8500/v1/catalog/service/web curl 'http://localhost:8500/v1/health/service/web?passing'
References
- A practical and simple consul-template example Tutorial with docker restart based on a template change
- Consul template Official Git repository