LOG-1840: Dev Preview Docs on how to get started with hacking on loki…

…-operator (grafana#99)

README.md

@@ -25,3 +25,6 @@ Build and push the container image and then deploy the operator with `make
 oci-build oci-push deploy IMG=quay.io/my-team/loki-operator:latest`.  This will
 deploy to your active Kubernetes/OpenShift cluster defined by your local
 [kubeconfig](https://kubernetes.io/docs/concepts/configuration/organize-cluster-access-kubeconfig/).
+
+For detailed step-by-step guide on how to start development and testing on Kind and OpenShift, 
+check our [documentation](https://github.com/ViaQ/loki-operator/blob/master/docs/hack_loki_operator.md)

docs/hack_loki_operator.md

@@ -0,0 +1,247 @@
+# Hacking on Loki Operator
+
+Loki Operator is the Kubernetes Operator for [Loki](https://grafana.com/docs/loki/latest/).
+
+## Hacking on Loki Operator using kind
+
+[kind](https://kind.sigs.k8s.io/docs/user/quick-start/) is a tool for running local Kubernetes clusters using Docker container "nodes". kind was primarily designed for testing Kubernetes itself, but may be used for local development or CI.
+
+### Requirements
+
+* Install [kubectl](https://kubernetes.io/docs/tasks/tools/#kubectl) or [Openshift CLI](https://docs.openshift.com/container-platform/latest/cli_reference/openshift_cli/getting-started-cli.html) for communicating with the cluster. The guide below will be using `kubectl` for the same.
+* Create a running Kubernetes cluster using kind.
+* A container registry that you and your Kubernetes cluster can reach. We recommend  [quay.io](https://quay.io/signin/).
+
+### Installation of Loki Operator
+
+* Build and push the container image and then deploy the operator with:
+
+  ```console
+  make oci-build oci-push deploy REGISTRY_ORG=$YOUR_QUAY_ORG VERSION=latest
+  ```
+
+  where `$YOUR_QUAY_ORG` is your personal [quay.io](http://quay.io/) account where you can push container images.
+
+  The above command will deploy the operator to your active Kubernetes cluster defined by your local [kubeconfig](https://kubernetes.io/docs/concepts/configuration/organize-cluster-access-kubeconfig/). The operator will be running in the `default` namespace.
+
+* You can confirm that the operator is up and running using:
+
+  ```console
+  kubectl get pods
+  ```
+  
+  You should see `controller-manager-xxxx` and `minio-xxxx` pods running.
+
+* Now create a LokiStack instance to get the various components of Loki up and running:
+
+  ```console
+  kubectl apply -f hack/lokistack_dev.yaml
+  ```
+
+  This will create `distributor`, `compactor`, `ingester`, `querier` and `query-frontend` components.
+
+  Confirm that all components are up and running for `deployments` using:
+
+  ```console  
+  kubectl rollout status deployment/<DEPLOYMENT_NAME>
+  ```  
+
+  where `<DEPLOYMENT_NAME>` is the name of the deployment and can be found using:
+
+  ```console
+  kubectl get deployments
+  ```
+
+  Confirm that all are up and running for `statefulsets` using:
+
+  ```console  
+  kubectl rollout status statefulset/<STATEFULSET_NAME>  
+  ```  
+
+  where `<STATEFULSET_NAME>` is the name of the statefulset and can be found using:
+
+  ```console
+  kubectl get statefulsets
+  ```
+
+### Cleanup
+
+To cleanup deployments of the operator, you can use:
+
+```console
+make undeploy
+```
+
+It will undeploy controller from the configured Kubernetes cluster in [~/.kube/config](https://kubernetes.io/docs/concepts/configuration/organize-cluster-access-kubeconfig/#the-kubeconfig-environment-variable)
+
+## Hacking on Loki Operator on OpenShift
+
+### Requirements
+
+* Install [kubectl](https://kubernetes.io/docs/tasks/tools/#kubectl) or [Openshift CLI](https://docs.openshift.com/container-platform/latest/cli_reference/openshift_cli/getting-started-cli.html) for communicating with the cluster. The guide below will be using `kubectl` for the same.
+* Create a running OpenShift cluster on AWS.
+* A container registry that you and your OpenShift cluster can reach. We recommend  [quay.io](https://quay.io/signin/).
+* Create an [S3 bucket](https://docs.aws.amazon.com/AmazonS3/latest/userguide/create-bucket-overview.html) in one of the AWS Regions.
+
+### Installation of Loki Operator
+
+* Build and push the container image [2] and then deploy the operator with:
+
+  ```console
+  make olm-deploy REGISTRY_ORG=$YOUR_QUAY_ORG VERSION=$VERSION
+  ```
+
+  where `$YOUR_QUAY_ORG` is your personal [quay.io](http://quay.io/) account where you can push container images and `$VERSION` can be any random version number such as `v0.0.1`.
+
+  The above command will deploy the operator to your active Openshift cluster defined by your local [kubeconfig](https://kubernetes.io/docs/concepts/configuration/organize-cluster-access-kubeconfig/). The operator will be running in the `openshift-logging` namespace.
+
+* You can confirm that the operator is up and running using:
+
+  ```console
+  kubectl -n openshift-logging get pods
+  ```
+
+* Now you need to create a storage secret for the operator. This can be done using:
+
+  ```console
+  make olm-deploy-example-storage-secret
+  ```
+
+  OR
+
+  ```console
+  ./hack/deploy-example-secret.sh openshift-logging
+  ```
+
+  This secret will be available in openshift-logging namespace. You can check the `hack/deploy-example-secret.sh` file to check the content of the secret.
+
+* Now you need to create a gateway secret [3] for the operator. This can be done using:
+
+  ```code
+  kubectl -n openshift-logging create secret generic test1 \
+    --from-literal=clientID="<CLIENT_ID>" \
+    --from-literal=clientSecret="<CLIENT_SECRET>" \
+    --from-literal=issuerCAPath="<ISSUER_CA_PATH>"
+  ```
+
+* Once the object storage secret is created, you can now create a LokiStack instance to get the various components of Loki up and running:
+
+  ```console
+  kubectl -n openshift-logging apply -f hack/lokistack_gateway_dev.yaml
+  ```
+
+  This will create `distributor`, `compactor`, `ingester`, `querier`, `query-frontend` and `lokistack-gateway` components.
+
+  Confirm that all are up and running for `deployments` using:
+
+  ```console  
+  kubectl -n openshift-logging rollout status deployment/<DEPLOYMENT_NAME>
+  ```  
+
+  where `<DEPLOYMENT_NAME>` is the name of the deployment and can be found using:
+
+  ```console
+  kubectl -n openshift-logging get deployments
+  ```
+
+  Confirm that all are up and running for `statefulsets` using:
+
+  ```console  
+  kubectl -n openshift-logging rollout status statefulset/<STATEFULSET_NAME>  
+  ```  
+
+  where `<STATEFULSET_NAME>` is the name of the statefulset and can be found using:
+
+  ```console
+  kubectl -n openshift-logging get statefulsets
+  ```
+
+  If you don't want `lokistack-gateway` component [1] then you can skip it by removing the `--with-lokistack-gateway` args from the `loki-operator-controller-manager` deployment:
+
+  ```console
+  kubectl -n openshift-logging edit deployment/loki-operator-controller-manager
+  ```
+
+  Delete the flag `--with-lokistack-gateway` from the `args` section and save the file. This will update the deployment and now you can create LokiStack instance using:
+
+  ```console
+  kubectl -n openshift-logging apply -f hack/lokistack_dev.yaml
+  ```
+
+  This will create `distributor`, `compactor`, `ingester`, `querier` and `query-frontend` components only.
+
+### Cleanup
+
+To cleanup deployments of the operator, you can use:
+
+```console
+make olm-undeploy
+```
+
+It will cleanup deployments of the operator bundle, and the operator via OLM on an OpenShift cluster selected via [~/.kube/config](https://kubernetes.io/docs/concepts/configuration/organize-cluster-access-kubeconfig/#the-kubeconfig-environment-variable)
+
+### Notes
+
+[1] `lokistack-gateway` is an optional component deployed as part of Loki Operator. It provides secure access to Loki's distributor (i.e. for pushing logs) and query-frontend (i.e. for querying logs) via consulting an OAuth/OIDC endpoint for the request subject.
+
+[2] If you get multiple images as options, and you are required to select one of them then select `docker.io/library/golang:1.16`
+
+[3] The OIDC configuration expects `clientID`, `clientSecret` and `issuerCAPath` which should be provided via a Kubernetes secret that the LokiStack admin provides upfront.
+
+Each tenant Secret is required to match:
+* `metadata.name` with `TenantsSecretsSpec.Name`.
+* `metadata.namespace` with `LokiStack.metadata.namespace`.
+
+## Basic Troubleshooting on Hacking on Loki Operator
+
+### New changes are not detected by Loki Operator
+
+Suppose you made some changes to the Loki Operator's code and deployed it, but the changes are not visible when it runs. This happens when the deployment pulls the old image of the operator because of the `imagePullPolicy` being set to `IfNotPresent`. Therefore, you need to make some changes to make your deployment pull a new image always:
+
+* Go to `config/manager/manager.yaml` file.
+* Set the `imagePullPolicy` to `Always` i.e.,
+
+  ```yaml
+  imagePullPolicy: Always
+  ```
+
+* Deploy the operator again.
+
+### kubectl using old context
+
+It is possible that when you use two different clusters - one is kind cluster and the other is OpenShift cluster, you might need to switch between clusters to test your changes. There is a possibility that once you switch between clusters, the kubectl might not switch the context automatically and hence you might need to do this manually to correctly communicate with your cluster.
+
+* List all the available context:
+
+  ```console
+  kubectl config get-contexts
+  ```
+
+  The `*` mark against the context shows the one in use currently.
+* Set the context name you want to use now:
+
+  ```console
+  kubectl config use-context $CONTEXTNAME
+  ```
+
+  where `$CONTEXTNAME` is the context name you want to use now from the previous step.
+
+### The Loki Operator giving Missing Secrets / Invalid Secrets error
+
+You have probably forgotten to create the gateway secrets because of which the operator runs in **degraded** condition. Follow the steps mentioned in the step-by-step guide to create the gateway secret first. Once done, you can now create the LokiStack instance.
+
+Verify this by checking the `conditions` field:
+
+```console
+kubectl get lokistack lokistack-dev -o yaml
+```
+
+For OpenShift, the above command would be:
+
+```console
+kubectl -n openshift-logging get lokistack lokistack-dev -o yaml
+```
+
+### The Loki Operator giving Mandatory Configuration / Incompatible Configuration error
+
+This usually happens when the LokiStack CR is wrongly configured for the lokistack-gateway. Please read the [enhancement proposal](https://github.com/openshift/enhancements/blob/master/enhancements/cluster-logging/loki-gateway-configuration.md) to figure out the correct way to configure it.

index.md

@@ -2,6 +2,12 @@
 
 This is the Kubernetes Operator for Loki provided by the Red Hat OpenShift engineering team. This is currently a work in progress and is subject to large scale changes that will break any dependencies. Do not use this in any production environment.
 
+### Hacking on Loki Operator on kind or OpenShift
+
+* If you want to contribute to this repository, you might need a step-by-step guide on how to start [hacking on Loki-operator with kind](https://github.com/ViaQ/loki-operator/blob/master/docs/hack_loki_operator.md#hacking-on-loki-operator-using-kind).
+* Also, there is a step-by-step guide on how to test Loki-operator on [OpenShift](https://github.com/ViaQ/loki-operator/blob/master/docs/hack_loki_operator.md#hacking-on-loki-operator-on-openshift).
+* There is also a [basic troubleshooting guide](https://github.com/ViaQ/loki-operator/blob/master/docs/hack_loki_operator.md#basic-troubleshooting-on-hacking-on-loki-operator) if you run into some common problems.
+
 ### Installation of Storage Size Calculator on OpenShift
 
 * Storage size calculator works out of the box on OpenShift. For non-openshift distributions you will need to create services like prometheus, serviceMonitor, scrape configuration for log-file-metric exporter, promsecret to access the custom prometheus URL, token.