osd: allow for injecting extra env. variables via ConfigMap

This patch brings a mechanism to define arbitrary environment
variables in OSD containers (both prepare and main ones).
It bases on idea proposed by Sebastien Han to use an optional
`ConfigMap` instance named `aook-ceph-daemon-env-override`
as the source of these settings.

The need for the patch comes from the fact that, although
crimson finally exposes the same CLI interface as the classical
OSD, the broadly used development builds have ASan built in.
As ASan, by default, complains if it isn't the very first loaded
DSO, we need a way to set the `ASAN_OPTIONS` environment variable
to `verify_asan_link_order=0` to mitigate the early aborts.

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>

deploy/examples/osd-env-override.yaml

@@ -0,0 +1,19 @@
+# ###############################################################################################################
+# The `rook-ceph-osd-env-override` ConfigMap is a development feature
+# that allows to inject arbitrary environment variables to OSD-related
+# containers created by the operator.
+# ###############################################################################################################
+
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: rook-ceph-osd-env-override
+  namespace: rook-ceph
+data:
+  # Bypass the ASan's assertion that it is the very first loaded DSO.
+  # This is necessary for crimson-osd as it's currently built with
+  # the ASan sanitizer turned on which means the `libasan.so` must
+  # the be the very first loaded dynamic library. Unfortunately, this
+  # isn't fulfilled as the containers use `ld.preload`, so ASan was
+  # aborting the entire OSD.
+  ASAN_OPTIONS: verify_asan_link_order=0

pkg/operator/ceph/cluster/osd/envs.go

@@ -32,6 +32,7 @@ const (
 	osdWalSizeEnvVarName      = "ROOK_OSD_WAL_SIZE"
 	osdsPerDeviceEnvVarName   = "ROOK_OSDS_PER_DEVICE"
 	osdDeviceClassEnvVarName  = "ROOK_OSD_DEVICE_CLASS"
+	osdConfigMapOverrideName  = "rook-ceph-osd-env-override"
 	// EncryptedDeviceEnvVarName is used in the pod spec to indicate whether the OSD is encrypted or not
 	EncryptedDeviceEnvVarName = "ROOK_ENCRYPTED_DEVICE"
 	PVCNameEnvVarName         = "ROOK_PVC_NAME"
@@ -213,6 +214,19 @@ func osdActivateEnvVar() []v1.EnvVar {
 	return append(cephVolumeEnvVar(), monEnvVars...)
 }
 
+func getEnvFromSources() []v1.EnvFromSource {
+	optionalConfigMapRef := true
+
+	return []v1.EnvFromSource{
+		{
+			ConfigMapRef: &v1.ConfigMapEnvSource{
+				LocalObjectReference: v1.LocalObjectReference{Name: osdConfigMapOverrideName},
+				Optional:             &optionalConfigMapRef,
+			},
+		},
+	}
+}
+
 func getTcmallocMaxTotalThreadCacheBytes(tcmallocMaxTotalThreadCacheBytes string) v1.EnvVar {
 	var value string
 	// If empty we read the default value from the file coming with the package

pkg/operator/ceph/cluster/osd/provision_spec.go

@@ -302,6 +302,7 @@ func (c *Cluster) provisionOSDContainer(osdProps osdProperties, copyBinariesMoun
 		Image:        c.spec.CephVersion.Image,
 		VolumeMounts: volumeMounts,
 		Env:          envVars,
+		EnvFrom:      getEnvFromSources(),
 		SecurityContext: &v1.SecurityContext{
 			Privileged:             &privileged,
 			RunAsUser:              &runAsUser,

pkg/operator/ceph/cluster/osd/spec.go

@@ -466,6 +466,7 @@ func (c *Cluster) makeDeployment(osdProps osdProperties, osd OSDInfo, provisionC
 				Image:           c.rookVersion,
 				VolumeMounts:    configVolumeMounts,
 				Env:             configEnvVars,
+				EnvFrom:         getEnvFromSources(),
 				SecurityContext: securityContext,
 			})
 	}
@@ -549,6 +550,7 @@ func (c *Cluster) makeDeployment(osdProps osdProperties, osd OSDInfo, provisionC
 					Image:           c.spec.CephVersion.Image,
 					VolumeMounts:    volumeMounts,
 					Env:             envVars,
+					EnvFrom:         getEnvFromSources(),
 					Resources:       osdProps.resources,
 					SecurityContext: securityContext,
 					StartupProbe:    controller.GenerateStartupProbeExecDaemon(opconfig.OsdType, osdID),
@@ -767,6 +769,7 @@ func (c *Cluster) getActivateOSDInitContainer(configDir, namespace, osdID string
 		VolumeMounts:    volMounts,
 		SecurityContext: controller.PrivilegedContext(true),
 		Env:             envVars,
+		EnvFrom:         getEnvFromSources(),
 		Resources:       osdProps.resources,
 	}