add-customer and introducing JpaAttempt test helper

README.md

@@ -51,13 +51,20 @@ If you have at least Docker, the Java JDK and Gradle installed in appropriate ve
 
     # the following command should return a JSON array with just all packages visible for the admin of the customer aab:
     curl \
-        -H 'current-user: mike@hostsharing.net' \
-        -H 'assumed-roles: customer#aab.admin' \
+        -H 'current-user: mike@hostsharing.net' -H 'assumed-roles: customer#aab.admin' \
         http://localhost:8080/api/packages
 
-The latter `curl` command actually goes through the database server.
+    # add a new customer
+    curl \
+        -H 'current-user: mike@hostsharing.net' -H "Content-Type: application/json" \
+        -d '{ "prefix":"baa", "reference":80001, "adminUserName":"admin@baa.example.com" }' \
+        -X POST http://localhost:8080/api/customers
 
-<big>&#9432;</big>
+<big>**&#9432;**</big>
+'mike@hostsharing.net' and 'sven@hostsharing.net' are Hostsharing hostmaster accounts coming from the example data which is automatically inserted in Testcontainers and Development environments.
+Also try for example 'admin@aaa.example.com' or 'unknown@example.org'.
+
+<big>**&#9432;**</big>
 If you want a formatted JSON output, you can pipe the result to `jq` or similar.
 
 If you still need to install some of these tools, find some hints in the next chapters. 
@@ -245,3 +252,26 @@ If the persistent database and the temporary database show different results, on
    e.g. from a previous run of tests or manually applied.
    It's best to run `pg-sql-reset && gw bootRun` before each test run, to have a clean database.
    
+## How to Amend Liquibase SQL Changesets?
+
+Liquibase changesets are meant to be immutable and based on each other.
+That means, once a changeset is written, it never changes, not even a whitespace or comment.
+Liquibase is a *database migration tool*, not a *database initialization tool*.
+
+This, if you need to add change a table, stored procedure or whatever, 
+create a new changeset and apply `ALTER`, `DROP`, `CREATE OR REPLACE` or whatever SQL commands to perform your changes.
+These changes will be automatically applied once the application starts up again.
+This way, any staging or production database will always match the application code. 
+
+But, during initial development that can be a big hassle because the database structure changes a lot in that stage.
+Also, the actual structure of the database won't be easily recognized anymore through lots of migration changesets.
+
+Therefore, during initial development, it's good approach just to amend the existing changesets and delete the database:
+
+```shell
+pg-sql-reset
+gw bootRun
+```
+
+<big>**&#9888;**</big>
+Just don't forget switching to the migration mode, once there is a production database!

src/main/java/net/hostsharing/hsadminng/errors/RestResponseEntityExceptionHandler.java

@@ -0,0 +1,57 @@
+package net.hostsharing.hsadminng.errors;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import lombok.Getter;
+import org.springframework.core.NestedExceptionUtils;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.orm.jpa.JpaSystemException;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+import java.time.LocalDateTime;
+
+@ControllerAdvice
+public class RestResponseEntityExceptionHandler
+    extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler(DataIntegrityViolationException.class)
+    protected ResponseEntity<CustomErrorResponse> handleConflict(
+        final RuntimeException exc, final WebRequest request) {
+
+        return new ResponseEntity<>(
+            new CustomErrorResponse(exc, HttpStatus.CONFLICT), HttpStatus.CONFLICT);
+    }
+
+    @ExceptionHandler(JpaSystemException.class)
+    protected ResponseEntity<CustomErrorResponse> handleJpaExceptions(
+        final RuntimeException exc, final WebRequest request) {
+
+        return new ResponseEntity<>(
+            new CustomErrorResponse(exc, HttpStatus.FORBIDDEN), HttpStatus.FORBIDDEN);
+    }
+}
+
+@Getter
+class CustomErrorResponse {
+
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd hh:mm:ss")
+    private final LocalDateTime timestamp;
+
+    private final HttpStatus status;
+
+    private final String message;
+
+    public CustomErrorResponse(final RuntimeException exc, final HttpStatus status) {
+        this.timestamp = LocalDateTime.now();
+        this.status = status;
+        this.message = firstLine(NestedExceptionUtils.getMostSpecificCause(exc).getMessage());
+    }
+
+    private String firstLine(final String message) {
+        return message.split("\\r|\\n|\\r\\n", 0)[0];
+    }
+}

src/main/java/net/hostsharing/hsadminng/hscustomer/CustomerController.java

@@ -2,16 +2,14 @@ package net.hostsharing.hsadminng.hscustomer;
 
 import net.hostsharing.hsadminng.context.Context;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Controller;
-import org.springframework.web.bind.annotation.RequestHeader;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
-import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.*;
 
 import javax.transaction.Transactional;
 import java.util.List;
+import java.util.UUID;
+
+@RestController
 
-@Controller
 public class CustomerController {
 
     @Autowired
@@ -20,18 +18,35 @@ public class CustomerController {
     @Autowired
     private CustomerRepository customerRepository;
 
-    @ResponseBody
-    @RequestMapping(value = "/api/customers", method = RequestMethod.GET)
+    @GetMapping(value = "/api/customers")
     @Transactional
     public List<CustomerEntity> listCustomers(
-            @RequestHeader(value = "current-user") String userName,
-            @RequestHeader(value="assumed-roles", required=false) String assumedRoles
+        @RequestHeader(value = "current-user") String userName,
+        @RequestHeader(value = "assumed-roles", required = false) String assumedRoles
     ) {
         context.setCurrentUser(userName);
-        if ( assumedRoles != null && !assumedRoles.isBlank() ) {
+        if (assumedRoles != null && !assumedRoles.isBlank()) {
             context.assumeRoles(assumedRoles);
         }
         return customerRepository.findAll();
     }
 
+    @PostMapping(value = "/api/customers")
+    @ResponseStatus
+    @Transactional
+    public CustomerEntity addCustomer(
+        @RequestHeader(value = "current-user") String userName,
+        @RequestHeader(value = "assumed-roles", required = false) String assumedRoles,
+        @RequestBody CustomerEntity customer
+    ) {
+        context.setCurrentUser(userName);
+        if (assumedRoles != null && !assumedRoles.isBlank()) {
+            context.assumeRoles(assumedRoles);
+        }
+        if (customer.getUuid() == null) {
+            customer.setUuid(UUID.randomUUID());
+        }
+        return customerRepository.save(customer);
+    }
+
 }

src/main/java/net/hostsharing/hsadminng/hscustomer/CustomerEntity.java

@@ -3,6 +3,7 @@ package net.hostsharing.hsadminng.hscustomer;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
+import lombok.Setter;
 
 import javax.persistence.*;
 import java.util.UUID;
@@ -10,6 +11,7 @@ import java.util.UUID;
 @Entity
 @Table(name = "customer_rv")
 @Getter
+@Setter
 @NoArgsConstructor
 @AllArgsConstructor
 public class CustomerEntity {

src/main/resources/db/changelog/2022-07-29-061-hs-customer-rbac.sql

@@ -210,7 +210,7 @@ create or replace function addCustomerNotAllowedForCurrentSubjects()
     language PLPGSQL
 as $$
 begin
-    raise exception 'add-customer not permitted for %', array_to_string(currentSubjects());
+    raise exception 'add-customer not permitted for %', array_to_string(currentSubjects(), ';', 'null');
 end; $$;
 
 /**