feat: add support for postgresql

Author: morremeyer

.vscode/launch.json

@@ -2,7 +2,7 @@
   "version": "0.2.0",
   "configurations": [
     {
-      "name": "Launch Package",
+      "name": "Run API (SQLite)",
       "type": "go",
       "request": "launch",
       "mode": "auto",

README.md

@@ -5,6 +5,62 @@ Envelope Zero is fundamentally rooted in two ideas:
 - Using the [envelope method](https://en.wikipedia.org/wiki/Envelope_system) to budget expenses into envelopes.
 - Zero Based Budeting, meaning that you assign all your money to an envelope. Saving for a vacation? Create an envelope and archive it after your vacation. Rent? Create an envelope that gets a fixed amount of money added every month.
 
+## Usage
+
+The recommended and only supported way for production deployments is to run the backend with [the OCI image](https://github.com/envelope-zero/backend/pkgs/container/backend).
+
+### Deployment methods
+
+If you want to deploy with a method not listed here, you are welcome to open a discussion to ask any questions needed so that this documentation can be improved.
+
+#### On Kubernetes
+
+You can run the backend on any Kubernetes cluster with a supported version using the [morremeyer/generic]() helm chart with the following values:
+
+```yaml
+image:
+  repository: ghcr.io/envelope-zero/backend
+  tag: v0.2.1
+
+# Only set this when you want to use sqlite as database backend.
+# In this case, you need to make sure the database is regularly backed up!
+persistence:
+  enabled: true
+  mountPath: /app/data
+
+ports:
+  - name: http
+    containerPort: 8080
+    protocol: TCP
+
+ingress:
+  enabled: true
+  hosts:
+    - host: envelope-zero.example.com
+      paths:
+        - path: /api
+  tls:
+    - hosts:
+        - envelope-zero.example.com
+```
+
+### Database backends
+
+Envelope Zero currently supports sqlite and postgresql as database backends. While sqlite is supported, it is highly recommended to use postgresql for production purposes.
+
+#### sqlite
+
+No configuration is needed, but you need to mount a persistent volume to the `/app/data` directory or the backend won’t start.
+
+#### postgresql
+
+Set the following environment variables:
+
+- `DB_HOST`: The hostname for the postgresql instance
+- `DB_USER`: The username to connect with
+- `DB_PASSWORD`: The password for `DB_USER`
+- `DB_NAME`: The name of the database to use
+
 ## Supported Versions
 
 This project is under heavy development. Therefore, only the latest release is supported.

go.mod

@@ -11,6 +11,14 @@ require (
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/jackc/chunkreader/v2 v2.0.1 // indirect
+	github.com/jackc/pgconn v1.10.1 // indirect
+	github.com/jackc/pgio v1.0.0 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgproto3/v2 v2.2.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20200714003250-2b9c44734f2b // indirect
+	github.com/jackc/pgtype v1.9.1 // indirect
+	github.com/jackc/pgx/v4 v4.14.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )
@@ -36,6 +44,7 @@ require (
 	golang.org/x/text v0.3.7 // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gorm.io/driver/postgres v1.3.1
 )
 
 replace github.com/envelope-zero/backend/internal/routing => ./internal/routing