use logfmt for audit logs

src/main/java/com/uid2/shared/audit/Audit.java

@@ -1,5 +1,6 @@
 package com.uid2.shared.audit;
 
+import com.uid2.shared.util.LogFmtLineBuilder;
 import io.vertx.core.MultiMap;
 import io.vertx.core.buffer.Buffer;
 import io.vertx.core.json.Json;
@@ -72,6 +73,29 @@ public String toString() {
             return toJson().encode();
         }
 
+        public String toLogFmtLine() {
+            LogFmtLineBuilder builder = new LogFmtLineBuilder();
+
+            builder.with("timestamp", timestamp.toString());
+            builder.with("log_type", logType);
+            builder.with("source", source);
+            builder.with("status", status);
+            builder.with("method", method);
+            builder.with("endpoint", endpoint);
+            builder.with("trace_id", traceId);
+            builder.with("actor", actor);
+            if (uidTraceId != null) {
+                builder.with("uid_trace_id", uidTraceId);
+            }
+            if (uidInstanceId != null) {
+                builder.with("uid_instance_id", uidInstanceId);
+            }
+            if (queryParams != null) builder.with("query_params", queryParams);
+            if (requestBody != null) builder.with("request_body", requestBody);
+
+            return builder.build();
+        }
+
         public static class Builder {
             private final int status;
             private final String method;
@@ -288,7 +312,7 @@ public void log(RoutingContext ctx, AuditParams params) {
             }
 
             AuditRecord auditRecord = builder.build();
-            LOGGER.info(auditRecord.toString());
+            LOGGER.info(auditRecord.toLogFmtLine());
         } catch (Exception e) {
             LOGGER.warn("Failed to log audit record", e);
         }

src/main/java/com/uid2/shared/util/LogFmtLineBuilder.java

@@ -0,0 +1,63 @@
+package com.uid2.shared.util;
+
+import io.vertx.core.json.JsonObject;
+
+import java.util.Map;
+
+public class LogFmtLineBuilder {
+    private final StringBuilder stringBuilder;
+
+    public LogFmtLineBuilder() {
+        this.stringBuilder = new StringBuilder();
+    }
+
+    private String escape(String value) {
+        if (value == null) {
+            return "null";
+        }
+
+        if (value.contains(" ") || value.contains("\"") || value.contains("=") || value.contains("\n") ||
+                value.contains("\r") || value.contains("\t") || value.contains("\\")) {
+            return "\"" + value.replace("\\", "\\\\")
+                    .replace("\"", "\\\"")
+                    .replace("\n", "\\n")
+                    .replace("\r", "\\r")
+                    .replace("\t", "\\t") + "\"";
+        }
+
+        return value;
+    }
+
+    public LogFmtLineBuilder with(String key, String value) {
+        if (!stringBuilder.isEmpty()) {
+            stringBuilder.append(" ");
+        }
+        stringBuilder.append(key).append("=").append(escape(value));
+        return this;
+    }
+
+    public LogFmtLineBuilder with(Map<String, String> map) {
+        if (map != null) {
+            for (Map.Entry<String, String> entry : map.entrySet()) {
+                with(entry.getKey(), entry.getValue());
+            }
+        }
+        return this;
+    }
+
+    public LogFmtLineBuilder with(String key, int value) {
+        return with(key, String.valueOf(value));
+    }
+
+    // Only supports one level of nesting
+    public LogFmtLineBuilder with(String key, JsonObject obj) {
+        for (String objKey : obj.fieldNames()) {
+            with(key+ "." + objKey, obj.getString(objKey));
+        }
+        return this;
+    }
+
+    public String build() {
+        return stringBuilder.toString();
+    }
+}

src/test/java/com/uid2/shared/audit/AuditTest.java

@@ -66,18 +66,13 @@ public void testAudit() throws JsonProcessingException {
         Optional<ILoggingEvent> maybeEvent = listAppender.list.stream()
                 .filter(event -> event.getFormattedMessage().contains("GET"))
                 .findFirst();
-        String jsonLog = maybeEvent.get().getFormattedMessage();
-        ObjectMapper mapper = new ObjectMapper();
-        JsonNode jsonNode = mapper.readTree(jsonLog);
-
-        assertThat(jsonNode.get("method").asText()).isEqualTo("GET");
-        assertThat(jsonNode.get("status").asInt()).isEqualTo(200);
-        assertThat(jsonNode.get("source").asText()).isEqualTo("admin");
-
-        JsonNode actor = jsonNode.get("actor");
-        assertThat(actor).isNotNull();
-        assertThat(actor.get("user_agent").asText()).isEqualTo("JUnit-Test-Agent");
-        assertThat(actor.get("ip").asText()).isEqualTo("127.0.0.1");
+        String auditLog = maybeEvent.get().getFormattedMessage();
+
+        assertThat(auditLog.contains("method=GET")).isTrue();
+        assertThat(auditLog.contains("status=200")).isTrue();
+        assertThat(auditLog.contains("source=admin")).isTrue();
+        assertThat(auditLog.contains("actor.user_agent=JUnit-Test-Agent")).isTrue();
+        assertThat(auditLog.contains("actor.ip=127.0.0.1")).isTrue();
 
     }