check-schema-changes has confusing error when released schema is modified

[prary]

Was fixing my stale PR https://github.com/GoogleContainerTools/skaffold/pull/3346 which earlier failed on make checks for some import disorder. Merged latest master code and ran make checks which again failed on hack/check-schema-changes.sh. I am bit confused how master builds are passing. Tried with fresh cloned code on master branch but failing on the hack/check-schema-changes.sh

Contributing guideline suggest to run ./hack/new_version.sh but I am not making changing schema.

Expected behavior

make checks should run successfully.

Actual behavior

Running validation scripts...
RUN hack/check-schema-changes.sh
INFO[0000] structural changes in latest config, checking on Github if latest is released... 
INFO[0000] Current Skaffold version: v2beta3            
v2beta3 is released, it should NOT be changed!
ERRO[0000] --------
Structural change detected in a released config: pkg/skaffold/schema/latest/config.go
Please create a new PR first with a new version.
You can use 'hack/new_version.sh' to generate the new config version.
If you are running this locally, make sure you have the origin/master branch up to date!
Admin rights are required to merge this PR!
-------- 
diff --git a/pkg/skaffold/schema/latest/config.go b/pkg/skaffold/schema/latest/config.go
index fd08129f4..a1cdee094 100644
--- a/pkg/skaffold/schema/latest/config.go
+++ b/pkg/skaffold/schema/latest/config.go
@@ -22,7 +22,7 @@ import (
        "github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/util"
 )
 
-// This config version is not yet released, it is SAFE TO MODIFY the structs in this file.
+// !!! WARNING !!! This config version is already released, please DO NOT MODIFY the structs in this file.
 const Version string = "skaffold/v2beta3"
 
 // NewSkaffoldConfig creates a SkaffoldConfig
@@ -317,6 +317,15 @@ type ClusterDetails struct {
        // DockerConfig describes how to mount the local Docker configuration into a pod.
        DockerConfig *DockerConfig `yaml:"dockerConfig,omitempty"`
 
+       // ServiceAccountName describes the Kubernetes service account to use for the pod.
+       // Defaults to 'default'.
+       ServiceAccountName string `yaml:"serviceAccount,omitempty"`
+
+       // RunAsUser defines the UID to request for running the container.
+       // If omitted, no SeurityContext will be specified for the pod and will therefore be inherited
+       // from the service account.
+       RunAsUser *int64 `yaml:"runAsUser,omitempty"`
+
        // Resources define the resource requirements for the kaniko pod.
        Resources *ResourceRequirements `yaml:"resources,omitempty"`

Output of ./hack/new_version.sh

ok      github.com/GoogleContainerTools/skaffold/cmd/skaffold/app       0.048s
FAIL    github.com/GoogleContainerTools/skaffold/cmd/skaffold/app/cmd   0.089s
ok      github.com/GoogleContainerTools/skaffold/cmd/skaffold/app/cmd/config    (cached)
ok      github.com/GoogleContainerTools/skaffold/cmd/skaffold/app/cmd/schema    0.028s
ok      github.com/GoogleContainerTools/skaffold/cmd/skaffold/app/flags (cached)
FAIL    github.com/GoogleContainerTools/skaffold/hack/man       0.059s
ok      github.com/GoogleContainerTools/skaffold/hack/schemas   0.892s
ok      github.com/GoogleContainerTools/skaffold/hack/versions/pkg/diff 0.034s
ok      github.com/GoogleContainerTools/skaffold/hack/versions/pkg/schema       (cached)
ok      github.com/GoogleContainerTools/skaffold/pkg/webhook/labels     (cached)

=== Failed Tests ===
/pkg/skaffold/schema/TestParseExamples
--- FAIL: TestParseExamples (0.00s)
/pkg/skaffold/schema/TestParseExamples/bazel
    TestParseExamples/bazel: samples_test.go:79: unexpected error: skaffold/v2bet3 is an invalid api version
    --- FAIL: TestParseExamples/bazel (0.00s)
panic: interface conversion: util.VersionedConfig is nil, not *latest.SkaffoldConfig [recovered]
        panic: interface conversion: util.VersionedConfig is nil, not *latest.SkaffoldConfig

Information

• Skaffold version: NA
• Operating system: linux
• Contents of skaffold.yaml:
• Go Version: go version go1.13.6 linux/amd64

[dgageot]

@prary This fails because your PR makes changes to a schema that was already released. You cannot change anything in pkg/skaffold/schema/latest/config.go b/pkg/skaffold/schema/latest/config.go. It requires to create a new schema, which @tejal29 just did.

[tstromberg]

I think we can make the error message here clearer.