Revert "Unpin Ubuntu Focal version by default"

This reverts commit b5a272e.

The DescribeRequest via Java SDK the filter didn't work like "contains", but as "equals".
Weird, because via GUI it always works like "contains". And on HTTP level the requests look almost identical (hostname is different).
Anyway, we're back to a pinned (and bumped) version.

CHANGELOG.md

@@ -27,8 +27,8 @@ Dropping a requirement of a major version of a dependency is a new contract.
 - Add `CanonicalAmiProvider.Builder.avoidUnattendedUpgrades` for bumping `imageName` to Focal or higher.
 
 ### Fixed
-- Unpin Ubuntu Focal version in `CanonicalAmiProvider.Builder` by default.
-  You can still pin a specific release date, e.g. `imageName("ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-20240531")`
+- Bump Ubuntu Focal AMI to `ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-20240531`.
+  The previous one was 2 years old and disappeared: `ubuntu-focal-20.04-amd64-server-20220610`.
 
 ## [1.15.0] - 2024-01-23
 [1.15.0]: https://github.com/atlassian-labs/aws-resources/compare/release-1.14.0...release-1.15.0

src/main/kotlin/com/atlassian/performance/tools/aws/api/CanonicalImageIdByNameResolver.kt

@@ -21,10 +21,14 @@ class CanonicalImageIdByNameResolver private constructor(
             )
         )
         .images
-        .sortedByDescending { it.creationDate }
         .map { it.imageId }
-        .firstOrNull()
-        ?: throw Exception("Failed to find image containing $imageName in $region")
+        .let {
+            when {
+                it.isEmpty() -> throw Exception("Failed to find image $imageName in $region")
+                it.size > 1 -> throw Exception("More than one image found with name $imageName in declared region $region. Selecting any of them automatically could create a security risk, so we can't proceed")
+                else -> it.first()
+            }
+        }
 
     class Builder(
         private val ec2: AmazonEC2

src/main/kotlin/com/atlassian/performance/tools/aws/api/ami/CanonicalAmiProvider.kt

@@ -32,7 +32,7 @@ class CanonicalAmiProvider private constructor(
     }
 
     class Builder {
-        private val focal = "ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server"
+        private val focal = "ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-20240531"
         private var imageName = focal
 
         /**

src/test/kotlin/com/atlassian/performance/tools/aws/api/CanonicalImageIdByNameResolverTest.kt

@@ -107,23 +107,27 @@ class CanonicalImageIdByNameResolverTest {
     }
 
     @Test
-    fun picksTheNewestImage() {
+    fun failsWhenMoreThanOneImageIsFound() {
         val queriedImageName = "name-of-single-image"
         val ec2 = object : AmazonEC2 by FakeEc2() {
             override fun describeImages(
                 describeImagesRequest: DescribeImagesRequest?
             ) = DescribeImagesResult()
                 .withImages(
-                    Image().withImageId("id-of-image-1").withCreationDate("2022-07-07T00:49:01.000Z"),
-                    Image().withImageId("id-of-image-2").withCreationDate("2024-03-21T22:43:23.000Z"),
-                    Image().withImageId("id-of-image-3").withCreationDate("2023-03-01T23:16:36.000Z")
+                    Image().withImageId("id-of-image-1"),
+                    Image().withImageId("id-of-image-2")
                 )
         }
         val resolver = CanonicalImageIdByNameResolver.Builder(ec2)
             .build()
 
-        val result = resolver.invoke(queriedImageName)
+        val result = try {
+            resolver.invoke(queriedImageName)
+            null
+        } catch (e: Exception) {
+            e
+        }
 
-        assertThat(result).isEqualTo("id-of-image-2")
+        assertThat(result).isNotNull()
     }
 }