postgres-operator/README.md

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# Postgres Operator
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## Introduction
The Postgres [operator](https://coreos.com/blog/introducing-operators.html)
manages PostgreSQL clusters on Kubernetes:
1. The operator watches additions, updates, and deletions of PostgreSQL cluster
manifests and changes the running clusters accordingly. For example, when a
user submits a new manifest, the operator fetches that manifest and spawns a
new Postgres cluster along with all necessary entities such as Kubernetes
StatefulSets and Postgres roles. See this
[Postgres cluster manifest](manifests/complete-postgres-manifest.yaml)
for settings that a manifest may contain.
2. The operator also watches updates to [its own configuration](manifests/configmap.yaml)
and alters running Postgres clusters if necessary. For instance, if a pod
docker image is changed, the operator carries out the rolling update. That
is, the operator re-spawns one-by-one pods of each StatefulSet it manages
with the new Docker image.
3. Finally, the operator periodically synchronizes the actual state of each
Postgres cluster with the desired state defined in the cluster's manifest.
## Quickstart
Prerequisites:
* [minikube](https://github.com/kubernetes/minikube/releases)
* [kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/#install-kubectl-binary-via-curl)
### Local execution
```bash
git clone https://github.com/zalando-incubator/postgres-operator.git
cd postgres-operator
minikube start
# start the operator; may take a few seconds
kubectl create -f manifests/configmap.yaml # configuration
kubectl create -f manifests/operator-service-account-rbac.yaml # identity and permissions
kubectl create -f manifests/postgres-operator.yaml # deployment
# create a Postgres cluster
kubectl create -f manifests/minimal-postgres-manifest.yaml
# connect to the Postgres master via psql
# operator creates the relevant k8s secret
export HOST_PORT=$(minikube service acid-minimal-cluster --url | sed 's,.*/,,')
export PGHOST=$(echo $HOST_PORT | cut -d: -f 1)
export PGPORT=$(echo $HOST_PORT | cut -d: -f 2)
export PGPASSWORD=$(kubectl get secret postgres.acid-minimal-cluster.credentials -o 'jsonpath={.data.password}' | base64 -d)
psql -U postgres
# tear down cleanly
minikube delete
```
We have automated starting the operator and submitting the `acid-minimal-cluster` for you:
```bash
cd postgres-operator
./run_operator_locally.sh
```
## Running and testing the operator
The best way to test the operator is to run it in [minikube](https://kubernetes.io/docs/getting-started-guides/minikube/).
Minikube is a tool to run Kubernetes cluster locally.
### Configuration Options
The operator can be configured with the provided ConfigMap (`manifests/configmap.yaml`).
## Table of contents
* [concepts](docs/concepts.md)
* [user documentation](docs/user.md)
* [administrator documentation](docs/administrator.md)
* [developer documentation](docs/developer.md)
* [reference](docs/reference.md)