Introduces Rancher's metadata service as an optional provider source for
Traefik, enabled by setting `rancher.MetadataService`.
The provider uses a long polling technique to watch the metadata service and
obtain near instantaneous updates. Alternatively it can be configured to poll
the metadata service every `rancher.RefreshSeconds` by setting
`rancher.MetadataPoll`.
The refactor splits API and metadata service code into separate source
files respectively, and specific configuration is deferred to
sub-structs.
Incorporates bugfix #1414
Now retries only happen when actual network errors occur and not only
anymore based on the HTTP status code. This is because the backend could
also send this status codes as their normal interface and in that case
we don't want to retry.
Copys the incoming TLS client certificate to the outgoing
request. The backend can then use this certificate for
client authentication ie. k8s client cert authentication
We previously did not copy the sticky flag if the load-balancer
method validation failed, causing enabled stickiness to be dropped in
case of a validation error (which, technically, for us is the same as a
load-balancer configuration without an explicitly set method). This
change fixes that.
A few refactorings and improvements along the way:
- Move the frontend and backend configuration steps into separate
methods/functions for better testability.
- Include the invalid method name in the error value and avoid log
duplication.
- Add tests for the backend configuration part.
- Improves default filtering behavior to filter by container health/healthState
- Optionally allows filtering by service health/healthState
- Allows configuration of refresh interval
For the two existing health check parameters (path and interval), we add
support for Marathon labels.
Changes in detail:
- Extend the Marathon provider and template.
- Refactor Server.loadConfig to reduce duplication.
- Refactor the healthcheck package slightly to accommodate the changes
and allow extending by future parameters.
- Update documentation.
- This will help split stuff in smaller, better tested packages
- This moves some stuff like the traefik command to package `cmd`
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
