Added Flagsmith (#600)

* Added Flagsmith

* Formatting

public/v4/apps/flagsmith.yml

@@ -0,0 +1,56 @@
+captainVersion: 4
+
+services:
+    $$cap_appname-db:
+        image: postgres:$$cap_postgres_version
+        volumes:
+            - '$$cap_appname-db-data:/var/lib/postgresql/data'
+        restart: unless-stopped
+        environment:
+            POSTGRES_USER: flagsmith
+            POSTGRES_PASSWORD: $$cap_postgres_password
+            POSTGRES_DB: $$cap_postgres_db
+        caproverExtra:
+            notExposeAsWebApp: true
+
+    $$cap_appname:
+        image: flagsmith/flagsmith:$$cap_flagsmith_tag
+        depends_on:
+            - $$cap_appname-db
+        restart: unless-stopped
+        environment:
+            DATABASE_URL: postgres://flagsmith:$$cap_postgres_password@srv-captain--$$cap_appname-db/$$cap_postgres_db?sslmode=disable
+            DJANGO_ALLOWED_HOSTS: '*'
+        caproverExtra:
+            containerHttpPort: '8000'
+
+caproverOneClickApp:
+    variables:
+        - id: $$cap_postgres_version
+          label: Postgres Version
+          defaultValue: '13.1'
+        - id: $$cap_postgres_db
+          label: Postgres DB
+          defaultValue: 'flagsmith'
+        - id: $$cap_postgres_password
+          label: Postgres Password
+          defaultValue: $$cap_gen_random_hex(16)
+          validRegex: /^(?=.*\d).{10,}$/
+        - id: $$cap_flagsmith_tag
+          label: Flagsmith Version
+          defaultValue: '2.14.3'
+          description: Check out our docker page for the valid tags https://hub.docker.com/r/flagsmith/flagsmith/tags
+    instructions:
+        start: >-
+            Flagsmith - an open source, fully featured, Feature Flag and Remote Config service. Use our hosted API, deploy to your own private cloud, or run on-premise.
+            For more info visit https://flagsmith.com/
+        end: |-
+            Flagsmith has been successfully deployed!
+            App is available as http://$$cap_appname.$$cap_root_domain
+
+    displayName: Flagsmith
+    isOfficial: true
+    description: >-
+        Flagsmith - an open source, fully featured, Feature Flag and Remote Config service. Use our hosted API, deploy to your own private cloud, or run on-premise.
+    documentation: >-
+        This docker-compose is taken from https://github.com/Flagsmith/self-hosted/blob/master/docker-compose.yml