possibility to configure etcd to listen on all interfaces (0.0.0.0)

[dahorak]

tendrl-ansible uses two variables related to the configuration of etcd with following description[1]:

• etcd_ip_address configures where etcd instance is listening,
• etcd_fqdn configure tendrl components to be able to connect to etcd instance

The first parameter - etcd_ip_address - is used to configure following two etcd configuration variables: ETCD_LISTEN_CLIENT_URLS and ETCD_ADVERTISE_CLIENT_URLS.
The second parameter - etcd_fqdn - is not directly used in etcd configuration, but it is used to configure etcd clients - where to connect to the etcd server.

The problem is, that ETCD_LISTEN_CLIENT_URLS might be configured with 0.0.0.0, which means, that etcd will listen on all interfaces[2].
But this value doesn't make sense for the ETCD_ADVERTISE_CLIENT_URLS - where should be valid IP or fqdn[3].

From my point of view, it will make sense to use the value from etcd_fqdn for ETCD_ADVERTISE_CLIENT_URLS.

So the configuration values will be used this way:

• etcd_ip_address => ETCD_LISTEN_CLIENT_URLS (as it is now)
• etcd_fqdn => ETCD_ADVERTISE_CLIENT_URLS (proposed change)

[1] https://github.com/Tendrl/tendrl-ansible/blob/master/README.md
[2] https://coreos.com/etcd/docs/latest/op-guide/configuration.html#listen-client-urls
[3] https://coreos.com/etcd/docs/latest/op-guide/configuration.html#advertise-client-urls

[mbukatov]

@dahorak Does you suggestion matches upstream documentation wiki page?

[dahorak]

@mbukatov good question, I've forgot to mention it.
Latest documentation (v1.6.2) states:

• ETCD_LISTEN_CLIENT_URLS="http://<ip address of etcd server>:2379"
• ETCD_ADVERTISE_CLIENT_URLS="http://<ip address of etcd server>:2379"

As a value for etcd server ip address, use some public ip address of the tendrl server machine (which is the server you are installing etcd on right now). This options controls where etcd server will listen on for client traffic.
For more details, see etcd configuration documentation.

Which would also deserve some clarification, because the first sentence is more applicable for the second parameter, while the second sentence is true for the first parameter.

[mbukatov]

@dahorak Thanks, this means that the wiki page installation description is misleading and needs to be clarified.

[mbukatov]

@r0h4n Does suggestion from @dahorak make sense?

[r0h4n]

Yes he makes sense, @dahorak is this proposed change tested?