Support prefix in context resolvers

sksamuel · May 27, 2023 · edf34aa · edf34aa
1 parent 0391dab
commit edf34aa
Show file tree

Hide file tree

Showing 3 changed files with 35 additions and 6 deletions.
diff --git a/hoplite-aws/src/test/kotlin/com/sksamuel/hoplite/aws/AwsSecretsManagerResolverTest.kt b/hoplite-aws/src/test/kotlin/com/sksamuel/hoplite/aws/AwsSecretsManagerResolverTest.kt
@@ -37,7 +37,7 @@ class AwsSecretsManagerResolverTest : FunSpec() {
     client.createSecret(CreateSecretRequest().withName("foo").withSecretString("secret!"))
     client.createSecret(CreateSecretRequest().withName("bubble").withSecretString("""{"f": "1", "g": "2"}"""))
 
-    test("placeholder should be detected and used") {
+    test("context pattern should be detected and used") {
       val props = Properties()
       props["a"] = "\${{ aws-secrets-manager:foo }}"
       ConfigLoaderBuilder.create()
@@ -48,6 +48,17 @@ class AwsSecretsManagerResolverTest : FunSpec() {
         .a.shouldBe("secret!")
     }
 
+    test("prefix pattern should be detected and used") {
+      val props = Properties()
+      props["a"] = "aws-secrets-manager://foo"
+      ConfigLoaderBuilder.create()
+        .addResolver(createAwsSecretsManagerResolver { client })
+        .addPropertySource(PropsPropertySource(props))
+        .build()
+        .loadConfigOrThrow<ConfigHolder>()
+        .a.shouldBe("secret!")
+    }
+
     test("unknown secret should return error and include key") {
       val props = Properties()
       props["a"] = "\${{ aws-secrets-manager:qwerty }}"

diff --git a/hoplite-core/src/main/kotlin/com/sksamuel/hoplite/resolver/ContextResolver.kt b/hoplite-core/src/main/kotlin/com/sksamuel/hoplite/resolver/ContextResolver.kt
@@ -15,7 +15,10 @@ import com.sksamuel.hoplite.fp.valid
  * A [ContextResolver] applies substitutions to context patterns in a [StringNode]'s value.
  *
  * Context patterns are of the form ${{ context:path }} where `context` indicates the context
- * resolver to use, and `path` is provided to that resolver for runtime resolution.
+ * resolver to use, and `path` is provided to that resolver for runtime resolution. Context
+ * patterns can be placed anywhere in a string, and can be nested.
+ *
+ * Additionally, we can use context://path to match a full string.
  *
  * For example, the [EnvVarContextResolver] will replace ${{ env:name }} with the env variable `name`,
  * and the [SystemPropertyContextResolver] will replace ${{ sysprop:name }} with the system property `name`.
@@ -31,7 +34,11 @@ abstract class ContextResolver : Resolver {
 
   // this regex will match most nested replacements first (inside to outside)
   // redundant escaping required for Android support
-  fun regex() = "\\$\\{\\{\\s*$contextKey:([^{}]*)\\}\\}".toRegex()
+  private fun contextRegex() = "\\$\\{\\{\\s*$contextKey:([^{}]*)\\}\\}".toRegex()
+
+  // this regex will match if the context is a prefex
+  // redundant escaping required for Android support
+  private fun prefixRegex() = "$contextKey://(.*)".toRegex()
 
   private val valueWithDefaultRegex = "(.+):-(.+)".toRegex()
 
@@ -57,7 +64,7 @@ abstract class ContextResolver : Resolver {
 
   private fun resolve(node: StringNode, root: Node, context: DecoderContext): ConfigResult<StringNode> {
 
-    val result = regex().find(node.value) ?: return node.valid()
+    val result = prefixRegex().matchEntire(node.value) ?: contextRegex().find(node.value) ?: return node.valid()
     val path = result.groupValues[1].trim()
 
     val matchWithDefault = valueWithDefaultRegex.matchEntire(path)

diff --git a/...te/resolver/SystemPropertyResolverTest.kt → ...lver/SystemPropertyContextResolverTest.kt b/...te/resolver/SystemPropertyResolverTest.kt → ...lver/SystemPropertyContextResolverTest.kt
@@ -8,9 +8,9 @@ import io.kotest.core.spec.style.FunSpec
 import io.kotest.extensions.system.withSystemProperty
 import io.kotest.matchers.shouldBe
 
-class SystemPropertyResolverTest : FunSpec({
+class SystemPropertyContextResolverTest : FunSpec({
 
-  test("should find matches") {
+  test("should support context matches") {
 
     val node = StringNode("boaty\${{sysprop:bar}}face", Pos.NoPos, DotPath.root)
 
@@ -21,6 +21,17 @@ class SystemPropertyResolverTest : FunSpec({
     (config.getUnsafe() as StringNode).value shouldBe "boatymcboatface"
   }
 
+  test("should support prefix matches") {
+
+    val node = StringNode("sysprop://bar", Pos.NoPos, DotPath.root)
+
+    val config = withSystemProperty(key = "bar", value = "mcboat") {
+      SystemPropertyContextResolver.resolve(node, node, DecoderContext.zero)
+    }
+
+    (config.getUnsafe() as StringNode).value shouldBe "mcboat"
+  }
+
   test("support leading whitespace") {
 
     val node = StringNode("boaty\${{  sysprop:bar}}face", Pos.NoPos, DotPath.root)