How to use engine-api to support api version 1.19, 1.18 or lower?

[allencloud]

As swarm uses engine-api to manage docker engines , there must be some api compatibility between swarm and docker engine.

Now latest version of Swarm is 1.2.3, it uses engine-api. If engine-api does not support lower api version, there is no way for Swarm to support lower version of docker engine, such as docker 1.6.x, docker 1.7.x.

I was wondering how to use engine-api to support api version 1.19, 1.18 or lower?

related issue in swarm:docker-archive/classicswarm#2330

Thanks in advance.

[vdemeester]

@allencloud which incompatibilaties did you have ? 😇

[allencloud]

@vdemeester
In docker version <= 1.6.2, in /info API, field Debug and SwapLimit is 0 which is a number, while in engine-api it should be the type of bool, so imcompatiblity happens.

related issue: docker-archive/classicswarm#2150

And in docker version less than <= 1.7.1, /events API does not work.

[allencloud]

@vdemeester
Can you help me to provide one example that how to use engine-api to communicate with lower version of docker engine such as 1.6.2?
To be honest, in our production environment, there still some can not easily updated to newer docker version. But we still hope to use engine-api which seems to be the future standard.