update for new docs

docs/user.md

@@ -242,3 +242,35 @@ metadata:
 
 Note that timezone required for `timestamp` (offset relative to UTC, see RFC
 3339 section 5.6)
+
+
+## Sidecar Support
+
+Each cluster can specify arbitrary sidecars to run. These containers could be used for
+log aggregation, monitoring, backups or other tasks. A sidecar can be specified like this:
+
+```yaml
+apiVersion: "acid.zalan.do/v1"
+kind: postgresql
+
+metadata:
+  name: acid-minimal-cluster
+spec:
+  ...
+  sidecars:
+    - name: "container-name"
+      image: "company/image:tag"
+      env:
+        - name: "ENV_VAR_NAME"
+          value: "any-k8s-env-things"
+```
+
+In addition to any environment variables you specify, the following environment variables
+are always passed to sidecars:
+
+  - `POD_NAME` - field reference to `metadata.name`
+  - `POD_NAMESPACE` - field reference to `metadata.namespace`
+  - `POSTGRES_USER` - the superuser that can be used to connect to the database
+  - `POSTGRES_PASSWORD` - the password for the superuser
+   
+The PostgreSQL volume is shared with sidecars and is mounted at `/home/postgres/pgdata`.

pkg/spec/postgresql.go

@@ -65,7 +65,7 @@ type CloneDescription struct {
 type Sidecar struct {
 	Resources   `json:"resources,omitempty"`
 	Name        string             `json:"name,omitempty"`
-	DockerImage string             `json:"dockerImage,omitempty"`
+	DockerImage string             `json:"image,omitempty"`
 	Ports       []v1.ContainerPort `json:"ports,omitempty"`
 	Env         []v1.EnvVar        `json:"env,omitempty"`
 }