Rancher DNS Service Discovery Improvements [#2628] - To be more aligned with Docker Engine 1.9, Rancher has now changed the behavior of the internal service discovery mechanism to the following:
- All services can now be discoverable by all other services without having to explicitly link them together. You can continue to use links for passing environment variables, aliasing DNS names, and for the UI to show service relationships.
- All containers within a service now have their own DNS entry.
- DNS service across stacks remain the same. An explicit link is required to create the DNS entry.
- Links to LB Services remain the same.
Known Major Issues
- Host IP changes to existing hosts managed by Rancher is known to cause problems. This is most prevalent in EC2 where a restart of a VM causes IPs to change [#2625]
Major Bug Fixes since v0.44.0
- Fixed many issues related to health monitoring and service HA. The general service HA should be vastly improved with this build [#2713, #2712, #2711, #2697, #2694, #2641, #2638, #2637, #2627, #2622, #2585]
- Fixed metadata to no longer report a removed container when a service has been scaled down [#2698]
- Fixed an issue where Rancher’s DNS was still reporting unhealthy containers [#2696]
- Fixed an issue where links to load balancers are updated before new services are up and running [#2668]
- Added instance.startCount to the API that allows users to determine how many times a container has been restarted [#2598]
- Fixed an issue where where the Rancher Route 53 service does not properly start up [#2621]
- Fixed an issue with in-service upgrade that would cause new containers to be created rather than restarting containers when the user initiates a rollback [#2589]
- Added ability to set TTL for Rancher Route 53 service [#2546]
- Fixed an issue with Rancher catalog to load improperly when the git repo had any forced changed [#2527]
- Added support for a service FQDN to be made available in the meta data service [#2508]
- Rancher will now enforce name uniqueness when creating a LB Service, Service Alias, or External Service per stack [#2447]
- Updated Rancher with cadvisor v0.19.3 which resolves several issues related to CoreOS and high CPU usage [#2241, #2380]
- Fixed an issue where published ports on containers launched in Rancher’s managed network does not get properly programmed [#1898]
- HealthChecks for Rancher’s LB service has been added to improve HA [#1721]
- rancher-compose: Rancher Interpolation now works with ‘=’ [#2518]
- rancher-compose: Fixed an issue where links for services were updated before services were active [#2668]