feat: also get database config from info controller as YAML

lapis2/src/main/kotlin/org/genspectrum/lapis/controller/Headers.kt

@@ -10,4 +10,5 @@ object LapisMediaType {
     const val TEXT_CSV = "text/csv"
     const val TEXT_CSV_WITHOUT_HEADERS = "text/csv;$HEADERS_ACCEPT_HEADER_PARAMETER=false"
     const val TEXT_TSV = "text/tab-separated-values"
+    const val APPLICATION_YAML = "application/yaml"
 }

lapis2/src/main/kotlin/org/genspectrum/lapis/controller/InfoController.kt

@@ -3,6 +3,7 @@ package org.genspectrum.lapis.controller
 import io.swagger.v3.oas.annotations.Operation
 import org.genspectrum.lapis.config.DatabaseConfig
 import org.genspectrum.lapis.config.ReferenceGenome
+import org.genspectrum.lapis.controller.LapisMediaType.APPLICATION_YAML
 import org.genspectrum.lapis.model.SiloQueryModel
 import org.genspectrum.lapis.request.LapisInfo
 import org.springframework.http.MediaType
@@ -28,9 +29,9 @@ class InfoController(
         return LapisInfo(siloInfo.dataVersion)
     }
 
-    @GetMapping(DATABASE_CONFIG_ROUTE, produces = [MediaType.APPLICATION_JSON_VALUE])
+    @GetMapping(DATABASE_CONFIG_ROUTE, produces = [MediaType.APPLICATION_JSON_VALUE, APPLICATION_YAML])
     @Operation(description = DATABASE_CONFIG_ENDPOINT_DESCRIPTION)
-    fun getDatabaseConfig(): DatabaseConfig = databaseConfig
+    fun getDatabaseConfigAsJson(): DatabaseConfig = databaseConfig
 
     @GetMapping(REFERENCE_GENOME_ROUTE, produces = [MediaType.APPLICATION_JSON_VALUE])
     @Operation(description = REFERENCE_GENOME_ENDPOINT_DESCRIPTION)

lapis2/src/main/kotlin/org/genspectrum/lapis/controller/YamlHttpMessageConverter.kt

@@ -0,0 +1,13 @@
+package org.genspectrum.lapis.controller
+
+import org.genspectrum.lapis.util.YamlObjectMapper
+import org.springframework.http.MediaType
+import org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter
+import org.springframework.stereotype.Component
+
+@Component
+class YamlHttpMessageConverter(yamlObjectMapper: YamlObjectMapper) :
+    AbstractJackson2HttpMessageConverter(
+        yamlObjectMapper.objectMapper,
+        MediaType.parseMediaType(LapisMediaType.APPLICATION_YAML),
+    )

lapis2/src/test/kotlin/org/genspectrum/lapis/controller/InfoControllerTest.kt

@@ -2,13 +2,16 @@ package org.genspectrum.lapis.controller
 
 import com.ninjasquad.springmockk.MockkBean
 import io.mockk.every
+import org.genspectrum.lapis.controller.LapisMediaType.APPLICATION_YAML
 import org.genspectrum.lapis.model.SiloQueryModel
 import org.genspectrum.lapis.response.InfoData
+import org.hamcrest.Matchers.startsWith
 import org.junit.jupiter.api.Test
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc
 import org.springframework.boot.test.context.SpringBootTest
 import org.springframework.test.web.servlet.MockMvc
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers.content
 import org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath
 import org.springframework.test.web.servlet.result.MockMvcResultMatchers.status
 
@@ -40,6 +43,21 @@ class InfoControllerTest(
             .andExpect(jsonPath("\$.schema.metadata[0].type").value("string"))
     }
 
+    @Test
+    fun `GET databaseConfig as YAML`() {
+        val yamlStart = """
+            ---
+            schema:
+              instanceName: "sars_cov-2_minimal_test_config"
+              opennessLevel: "OPEN"
+        """.trimIndent()
+
+        mockMvc.perform(getSample(DATABASE_CONFIG_ROUTE).accept(APPLICATION_YAML))
+            .andExpect(status().isOk)
+            .andExpect(content().contentType(APPLICATION_YAML))
+            .andExpect(content().string(startsWith(yamlStart)))
+    }
+
     @Test
     fun `GET referenceGenome`() {
         mockMvc.perform(getSample(REFERENCE_GENOME_ROUTE))