From f6a6f8f3e2ba41b44c2e9490b9dc2cc013fa2994 Mon Sep 17 00:00:00 2001
From: Titouan BION <titouan.bion@gmail.com>
Date: Sat, 13 Feb 2021 23:25:18 +0100
Subject: Add Loki logback appender to push server logs to the free cloud
 hosted Loki instance provided by Grafana.com

---
 kubernetes/server.yml                    | 11 +++++++++
 sw-server/build.gradle.kts               |  3 ++-
 sw-server/src/main/resources/logback.xml | 38 ++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 sw-server/src/main/resources/logback.xml

diff --git a/kubernetes/server.yml b/kubernetes/server.yml
index 6dbc751d..3838bdfb 100644
--- a/kubernetes/server.yml
+++ b/kubernetes/server.yml
@@ -15,6 +15,17 @@ spec:
     spec:
       containers:
         - name: seven-wonders-server
+          env:
+            - name: LOKI_USERNAME
+              valueFrom:
+                secretKeyRef:
+                  name: loki-credentials
+                  key: username
+            - name: LOKI_PASSWORD
+              valueFrom:
+                secretKeyRef:
+                  name: loki-credentials
+                  key: api-key
           image: hildan/seven-wonders-server:latest
           ports:
             - containerPort: 80
diff --git a/sw-server/build.gradle.kts b/sw-server/build.gradle.kts
index a129f952..445ae4d8 100644
--- a/sw-server/build.gradle.kts
+++ b/sw-server/build.gradle.kts
@@ -24,7 +24,8 @@ dependencies {
     implementation("org.springframework.security:spring-security-messaging")
 
     // logging
-    implementation("ch.qos.logback:logback-classic:1.1.8")
+    implementation("ch.qos.logback:logback-classic:1.2.3")
+    implementation("com.github.loki4j:loki-logback-appender:1.0.0")
 
     // monitoring / metrics
     implementation("org.springframework.boot:spring-boot-starter-actuator")
diff --git a/sw-server/src/main/resources/logback.xml b/sw-server/src/main/resources/logback.xml
new file mode 100644
index 00000000..c87e740c
--- /dev/null
+++ b/sw-server/src/main/resources/logback.xml
@@ -0,0 +1,38 @@
+<configuration>
+    <include resource="org/springframework/boot/logging/logback/defaults.xml"/>
+    <include resource="org/springframework/boot/logging/logback/console-appender.xml"/>
+
+    <appender name="LOKI" class="com.github.loki4j.logback.InstrumentedLoki4jAppender">
+        <!--
+             Loki Cloud hosted solution is limiting the batch size to 65536 Bytes, our log lines are exceeding this
+             limit quite often so we are sending them with a granularity of 1 instead of the default 1000.
+             The library does not provide a `batchSize` expressed in Bytes yet, so we cannot set it smarter than that.
+        -->
+        <batchSize>1</batchSize>
+        <batchTimeoutMs>10000</batchTimeoutMs>
+        <http>
+            <url>https://logs-prod-us-central1.grafana.net/loki/api/v1/push</url>
+            <auth>
+                <username>${LOKI_USERNAME}</username>
+                <password>${LOKI_PASSWORD}</password>
+            </auth>
+            <requestTimeoutMs>15000</requestTimeoutMs>
+        </http>
+        <format>
+            <label>
+                <pattern>application=seven-wonders,instance=${HOSTNAME},level=%level,class=%logger</pattern>
+            </label>
+            <message>
+                <pattern>level=%level class=%logger thread=%thread | %msg %ex</pattern>
+            </message>
+        </format>
+    </appender>
+
+    <root level="DEBUG">
+        <appender-ref ref="CONSOLE"/>
+    </root>
+    <root level="INFO">
+        <appender-ref ref="LOKI"/>
+    </root>
+
+</configuration>
-- 
cgit