metallb: Add alerts for metallb

[surajssd]

This commit adds a prometheus operator CR PrometheusRule which includes
alertmanager rules for metallb.

• This sends an alert when it sees that a session is not established for
  more than 2mins.

• This sends an alert when any of the pods have stale config.

Signed-off-by: Suraj Deshmukh suraj@kinvolk.io

[surajssd]

TODO: Add retry logic to the tests. This will buy some time for the prometheus to reconcile.

[invidian]

The alternative for PLATFORM environment variable would be something like this:

new file mode 100644
index 00000000..4939ffc1
--- /dev/null
+++ b/test/components/util/platform_generic.go
@@ -0,0 +1,20 @@
+// Copyright 2020 The Lokomotive Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !packet !aws
+
+package util
+
+const Platform = PlatformAll
diff --git a/test/components/util/platform_aws.go b/test/components/util/platform_aws.go
new file mode 100644
index 00000000..ad6050f9
--- /dev/null
+++ b/test/components/util/platform_aws.go
@@ -0,0 +1,20 @@
+// Copyright 2020 The Lokomotive Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build aws
+
+package util
+
+const Platform = PlatformAWS
diff --git a/test/components/util/platform.go b/test/components/util/platform.go
new file mode 100644
index 00000000..ad6050f9
--- /dev/null
+++ b/test/components/util/platform.go
@@ -0,0 +1,20 @@
+// Copyright 2020 The Lokomotive Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package util
+
+const (
+  PlatformAWS = "aws"
+  PlatformPacket = "packet"
+  PlatformAll = "generic"
+)
+
+type PlatformSelector struct {
+  Include []string
+  Exlude []string
+}
+
+func IsPlatformSupported(t *testing.T, ps *PlatformSelector) {
+  if ps == nil {
+    return
+  }
+
+  for _, p := range ps.Include {
+    if p == Platform {
+      return
+    }
+  }
+
+  for _, p := range ps.Exclude {
+    if p == Platform {
+      t.Skip("Not supported on platform %q", Platform)
+    }
+  }
+
+  return t.Skip("Not supported on platform %q", Platform)
+  }

This way, the test would define following value in test matrix:

PlatformSelector: util.PlatformSelector{
  Exclude: []string{
    util.PlatformBareMetal,
  },
}

Or the field would be skipped if test is intended to run on all platforms.

Then, when running tests, following needs to be used:

  util.IsPlatformSupported(t, testCase.PlatformSelector)

[surajssd]

I think we are using build-time information for something that should be run-time information. IMO tags should represent things like the kind of tests (integration, unit, e2e, and so on) and for run-time information (like the platform we're running on) we should use env variables that we can check at run-time.

The platform is already passed as an env variable to Make, we're just placing that into build tags, which I don't think makes sense if we want to have shared logic in tests. I'd remove all build tags and use env variables, but that's a bigger task.

About the structuring of tests in this PR it seems OK to me.

@iaguis Most of these concerns will be addressed in #212.

[invidian]

Just one last nit, otherwise LGTM

[iaguis]

@invidian can you review again?