che: PKIX error and impossible to start workspaces on OCP 4.1

Description

2019-06-21 08:52:06,511[557-wjt8m-47779]  [WARN ] [unknown.jul.logger 49]               - Problem getting Pod json from Kubernetes Client[masterUrl=https://172.30.0.1:443/api/v1, headers={}, connectTimeout=5000, readTimeout=30000, operationAttempts=3, operationSleep=1000, streamProvider=org.openshift.ping.common.stream.TokenStreamProvider@3d3d5e6a] for cluster [EclipseLinkCommandChannel], namespace [che7], labels [app=che]; encountered [java.lang.Exception: 3 attempt(s) with a 1000ms sleep to execute [OpenStream] failed. Last failure was [javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target]]

And then:

2019-06-21 08:52:06,965[aceSharedPool-1]  [WARN ] [.i.k.KubernetesInternalRuntime 245]  - Failed to start Kubernetes runtime of workspace workspacef4huz4zllvbwgxom. Cause: Pod creation timeout exceeded. -id: workspacef4huz4zllvbwgxom.workspace -message: null

Reproduction Steps

• Deploy Che 7 RC 2 on OCP 4.1
• Create 5 workspaces
• stop all of them
• try to start a new workspace.

OS and version:
Che 7 RC 2 - OCP 4.1