From dc73e57ba83d8e84d7a1ef0bbefff15189e174f3 Mon Sep 17 00:00:00 2001
From: Adria Navarro <adria@budibase.com>
Date: Tue, 11 Jul 2023 13:48:52 +0200
Subject: [PATCH] Respect max values

---
 packages/backend-core/src/environment.ts      |  2 +-
 packages/backend-core/src/logging/system.ts   | 40 +++++++++++-
 .../src/logging/tests/system.spec.ts          | 61 +++++++++++++++++++
 3 files changed, 100 insertions(+), 3 deletions(-)
 create mode 100644 packages/backend-core/src/logging/tests/system.spec.ts

diff --git a/packages/backend-core/src/environment.ts b/packages/backend-core/src/environment.ts
index 5a230f6925..a5a231fb27 100644
--- a/packages/backend-core/src/environment.ts
+++ b/packages/backend-core/src/environment.ts
@@ -168,7 +168,7 @@ const environment = {
     // @ts-ignore
     environment[key] = value
   },
-  ROLLING_LOG_MAX_SIZE: process.env.ROLLING_LOG_MAX_SIZE || "100M",
+  ROLLING_LOG_MAX_SIZE: process.env.ROLLING_LOG_MAX_SIZE || "20M",
 }
 
 // clean up any environment variable edge cases
diff --git a/packages/backend-core/src/logging/system.ts b/packages/backend-core/src/logging/system.ts
index 76f6ad1098..9a32b69a9f 100644
--- a/packages/backend-core/src/logging/system.ts
+++ b/packages/backend-core/src/logging/system.ts
@@ -14,11 +14,47 @@ function getFullPath(fileName: string) {
   return path.join(logsPath, fileName)
 }
 
+export function getSingleFileMaxSizeInfo(totalMaxSize: string) {
+  const regex = /(\d+)([A-Za-z])/
+  const match = totalMaxSize?.match(regex)
+  if (!match) {
+    console.warn(`totalMaxSize does not have a valid value`, {
+      totalMaxSize,
+    })
+    return undefined
+  }
+
+  const size = +match[1]
+  const unit = match[2]
+  if (size === 1) {
+    switch (unit) {
+      case "B":
+        return { size: `${size}B`, totalHistoryFiles: 1 }
+      case "K":
+        return { size: `${(size * 1000) / 2}B`, totalHistoryFiles: 1 }
+      case "M":
+        return { size: `${(size * 1000) / 2}K`, totalHistoryFiles: 1 }
+      case "G":
+        return { size: `${(size * 1000) / 2}M`, totalHistoryFiles: 1 }
+      default:
+        return undefined
+    }
+  }
+
+  if (size % 2 === 0) {
+    return { size: `${size / 2}${unit}`, totalHistoryFiles: 1 }
+  }
+
+  return { size: `1${unit}`, totalHistoryFiles: size }
+}
+
 export function localFileDestination() {
+  const fileInfo = getSingleFileMaxSizeInfo(env.ROLLING_LOG_MAX_SIZE)
   const outFile = rfs.createStream(logsFileName, {
-    size: env.ROLLING_LOG_MAX_SIZE,
+    // As we have a rolling size, we want to half the max size
+    size: fileInfo?.size,
     path: logsPath,
-    maxFiles: 1,
+    maxFiles: fileInfo?.totalHistoryFiles || 1,
     immutable: true,
     history: budibaseLogsHistoryFileName,
     initialRotation: false,
diff --git a/packages/backend-core/src/logging/tests/system.spec.ts b/packages/backend-core/src/logging/tests/system.spec.ts
new file mode 100644
index 0000000000..f756d59e2b
--- /dev/null
+++ b/packages/backend-core/src/logging/tests/system.spec.ts
@@ -0,0 +1,61 @@
+import { getSingleFileMaxSizeInfo } from "../system"
+
+describe("system", () => {
+  describe("getSingleFileMaxSizeInfo", () => {
+    it.each([
+      ["100B", "50B"],
+      ["200K", "100K"],
+      ["20M", "10M"],
+      ["4G", "2G"],
+    ])(
+      "Halving even number (%s) returns halved size and 1 history file (%s)",
+      (totalValue, expectedMaxSize) => {
+        const result = getSingleFileMaxSizeInfo(totalValue)
+        expect(result).toEqual({
+          size: expectedMaxSize,
+          totalHistoryFiles: 1,
+        })
+      }
+    )
+
+    it.each([
+      ["5B", "1B", 5],
+      ["17K", "1K", 17],
+      ["21M", "1M", 21],
+      ["3G", "1G", 3],
+    ])(
+      "Halving an odd number (%s) returns as many files as size (%s)",
+      (totalValue, expectedMaxSize, totalHistoryFiles) => {
+        const result = getSingleFileMaxSizeInfo(totalValue)
+        expect(result).toEqual({
+          size: expectedMaxSize,
+          totalHistoryFiles,
+        })
+      }
+    )
+
+    it.each([
+      ["1B", "1B"],
+      ["1K", "500B"],
+      ["1M", "500K"],
+      ["1G", "500M"],
+    ])(
+      "Halving '%s' returns halved unit (%s)",
+      (totalValue, expectedMaxSize) => {
+        const result = getSingleFileMaxSizeInfo(totalValue)
+        expect(result).toEqual({
+          size: expectedMaxSize,
+          totalHistoryFiles: 1,
+        })
+      }
+    )
+
+    it.each([[undefined], [""], ["50"], ["wrongvalue"]])(
+      "Halving wrongly formatted value ('%s') returns undefined",
+      totalValue => {
+        const result = getSingleFileMaxSizeInfo(totalValue!)
+        expect(result).toBeUndefined()
+      }
+    )
+  })
+})