Fix/try redict (#569)

README.md

@@ -57,10 +57,10 @@ To only disable comparing the variable file to the template, set
 
 To run only the tasks related to some of the services, this way doing a
 partial deployment, you can set the `TAGS` environment variable before calling
-`make`. For example, to run only the tasks to deploy Redis and Redis
+`make`. For example, to run only the tasks to deploy Redict and Redis
 Commander, run:
 
-    $ DEPLOYMENT=dev TAGS="redis,redis-commander" make deploy
+    $ DEPLOYMENT=dev TAGS="redict,redis-commander" make deploy
 
 Use `make tags` to list the currently available tags.
 

docs/deployment/specifics/redict.md

@@ -0,0 +1,71 @@
+---
+title: Redict
+---
+
+## Seamless migration between providers
+
+We have tested a seamless migration from Redis to Redict on our production
+deployment. To reproduce:
+
+1. We have deployed Redict to our production cluster.
+
+   - Defaults have been changed to:
+
+     ```yaml
+     with_redis: false
+     with_redict: true
+     ```
+
+     These can be changed in their respective `vars/` files.
+
+   - Run
+
+     ```
+     DEPLOYMENT=prod TAGS=redict make deploy
+     ```
+
+2. Using remote shell and `redict-cli` run:
+
+   ```sh
+   replicaof redis 6379
+   ```
+
+   This converts the Redict instance into a read-only replica of the Redis.
+
+3. After the data exchange is done, change **all** references in variables to
+   redis to point to the new hostname, in this case `redis → redict`.
+
+   - Run
+
+     ```
+     DEPLOYMENT=prod TAGS=packit-service-beat,fedmsg,packit-worker,packit-service make deploy
+     ```
+
+4. Simultaneously run the deployment with the changed hostnames and via
+   `redict-cli` run:
+
+   ```sh
+   replicaof no one
+   ```
+
+   to make the redict deployment the primary one.
+
+5. (optional) For safety reasons and easier rollback, it's possible to convert
+   the former Redis deployment into a replica of Redict, just in case it needs
+   to be reverted without loss of data. For this you can run in `redis-cli`:
+
+   ```sh
+   replicaof redict 6379
+   ```
+
+:::warning References to Redis
+
+Redis is being referenced from:
+
+- `packit-service` (API endpoint)
+- `packit-service-fedmsg` (Fedora Messaging listener)
+- `packit-service-beat` (triggers periodic tasks)
+- `packit-worker` (runs the jobs provided by API, Fedora Messaging and “beat”)
+- `flower` (monitoring of the Celery queues)
+
+:::

openshift/flower.yml.j2

@@ -23,7 +23,7 @@ spec:
           image: quay.io/packit/flower
           env:
             - name: CELERY_BROKER_URL
-              value: redis://redis:6379/0
+              value: redis://{{ redis_hostname }}:6379/0
             - name: FLOWER_PORT
               value: "5555"
           ports:

openshift/packit-service-beat.yml.j2

@@ -41,7 +41,7 @@ spec:
             - name: APP
               value: {{ celery_app }}
             - name: REDIS_SERVICE_HOST
-              value: redis
+              value: {{ redis_hostname }}
             - name: POSTGRESQL_USER
               valueFrom: {secretKeyRef: {name: postgres-secret, key: database-user}}
             - name: POSTGRESQL_PASSWORD

openshift/packit-service-fedmsg.yml.j2

@@ -33,7 +33,7 @@ spec:
             - name: FEDORA_MESSAGING_CONF
               value: /home/packit/.config/fedora.toml
             - name: REDIS_SERVICE_HOST
-              value: redis
+              value: {{ redis_hostname }}
             - name: PROJECT
               value: {{ project }}
             - name: DEPLOYMENT

openshift/packit-service.yml.j2

@@ -52,7 +52,7 @@ spec:
             - name: DISTGIT_NAMESPACE
               value: {{ distgit_namespace }}
             - name: REDIS_SERVICE_HOST
-              value: redis
+              value: {{ redis_hostname }}
             - name: POSTGRESQL_USER
               valueFrom: {secretKeyRef: {name: postgres-secret, key: database-user}}
             - name: POSTGRESQL_PASSWORD

openshift/packit-worker.yml.j2

@@ -86,7 +86,7 @@ spec:
             - name: APP
               value: {{ celery_app }}
             - name: REDIS_SERVICE_HOST
-              value: redis
+              value: {{ redis_hostname }}
             - name: POSTGRESQL_USER
               valueFrom: {secretKeyRef: {name: postgres-secret, key: database-user}}
             - name: POSTGRESQL_PASSWORD

openshift/redict.yml.j2

@@ -0,0 +1,79 @@
+# Copyright Contributors to the Packit project.
+# SPDX-License-Identifier: MIT
+
+---
+kind: Deployment
+apiVersion: apps/v1
+metadata:
+  name: redict
+spec:
+  selector:
+    matchLabels:
+      component: redict
+  template:
+    metadata:
+      labels:
+        component: redict
+{% if managed_platform %}
+        paas.redhat.com/appcode: {{ appcode }}
+{% endif %}
+    spec:
+      containers:
+        - name: redict
+          image: registry.redict.io/redict:7
+          ports:
+            - containerPort: 6379
+          volumeMounts:
+            - mountPath: /data
+              name: redict-pv
+          resources:
+            # requests and limits have to be the same to have Guaranteed QoS
+            requests:
+              memory: "128Mi"
+              cpu: "10m"
+            limits:
+              memory: "256Mi"
+              cpu: "10m"
+      volumes:
+        - name: redict-pv
+          persistentVolumeClaim:
+            claimName: redict-pvc
+  replicas: 1
+  strategy:
+    type: Recreate
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: redict
+{% if managed_platform %}
+  labels:
+    paas.redhat.com/appcode: {{ appcode }}
+{% endif %}
+spec:
+  ports:
+    - name: "6379"
+      port: 6379
+      targetPort: 6379
+  selector:
+    component: redict
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: redict-pvc
+{% if managed_platform %}
+  labels:
+    paas.redhat.com/appcode: {{ appcode }}
+  annotations:
+    kubernetes.io/reclaimPolicy: Delete
+{% endif %}
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 1Gi
+{% if managed_platform %}
+  storageClassName: aws-ebs
+{% endif %}

openshift/redis-commander.yml.j2

@@ -23,7 +23,7 @@ spec:
           image: rediscommander/redis-commander
           env:
             - name: REDIS_HOST
-              value: redis
+              value: {{ redis_hostname }}
             - name: REDIS_PORT
               value: "6379"
             - name: HTTP_USER

playbooks/deploy.yml

@@ -12,6 +12,8 @@
     tenant: packit # MP+ tenant
     with_tokman: true
     with_fedmsg: true
+    with_redis: false
+    with_redict: true
     with_redis_commander: false
     with_flower: false
     with_dashboard: true
@@ -183,9 +185,20 @@
       ansible.builtin.include_tasks: tasks/k8s.yml
       loop:
         - "{{ lookup('template', '{{ project_dir }}/openshift/redis.yml.j2') }}"
+      when: with_redis
       tags:
         - redis
 
+    - name: Deploy redict
+      vars:
+        k8s_apply: true
+      ansible.builtin.include_tasks: tasks/k8s.yml
+      loop:
+        - "{{ lookup('template', '{{ project_dir }}/openshift/redict.yml.j2') }}"
+      when: with_redict
+      tags:
+        - redict
+
     - name: Deploy fluentd image stream and config
       ansible.builtin.include_tasks: tasks/k8s.yml
       loop:

playbooks/tasks/set-deployment-facts.yml

@@ -9,10 +9,10 @@
   ansible.builtin.set_fact:
     mandatory_deploymentconfigs:
       - postgres-{{ postgres_version }}
-      - redis
       - packit-service
   tags:
     - always
+
 - name: Set optional_deploymentconfigs fact
   ansible.builtin.set_fact:
     optional_deploymentconfigs:
@@ -22,8 +22,11 @@
       packit-dashboard: "{{ with_dashboard }}"
       pushgateway: "{{ with_pushgateway }}"
       nginx: "{{ with_pushgateway }}"
+      redis: "{{ with_redis }}"
+      redict: "{{ with_redict }}"
   tags:
     - always
+
 - name: Set deploymentconfigs fact
   ansible.builtin.set_fact:
     # To know what DCs rollouts to wait for and also to check in tests

playbooks/tasks/set-facts.yml

@@ -27,3 +27,31 @@
       ansible.builtin.set_fact:
         sandbox_namespace: "{{ service }}-{{ deployment }}-sandbox"
       when: not managed_platform
+
+- name: Set Redis-like hostname
+  tags:
+    - always
+  block:
+    # Needed for nice message of the sanity check
+    - name: Set default for the hostname
+      ansible.builtin.set_fact:
+        redis_hostname: None
+
+    - name: Set Redict as the hostname
+      ansible.builtin.set_fact:
+        redis_hostname: redict
+      when: with_redict
+
+    - name: Set Redis as the hostname (backward compatibility)
+      ansible.builtin.set_fact:
+        redis_hostname: redis
+      when: with_redis
+
+    - name: Sanity check for deploying exactly one of Redis or Redict
+      ansible.builtin.assert:
+        that: with_redict != with_redis
+        success_msg: |
+          [INFO] Deploying {{ redis_hostname }}
+        fail_msg: |
+          [FAIL] Check vars (‹with_redict› and ‹with_redis›).
+          Cannot deploy none or both of Redis and Redict!