[substitutor] enable to decode a base64 string

bundlebee-core/src/main/java/io/yupiik/bundlebee/core/lang/SubstitutorProducer.java

@@ -249,9 +249,16 @@ protected String doSubstitute(final AtomicReference<Substitutor> self, final Con
                 final var src = readResource(placeholder, "bundlebee-base64-file:");
                 return src == null ? null : Base64.getEncoder().encodeToString(src);
             }
+            if (placeholder.startsWith("bundlebee-base64-decode-file:")) {
+                final var src = readResource(placeholder, "bundlebee-base64-decode-file:");
+                return src == null ? null : new String(Base64.getDecoder().decode(src), StandardCharsets.UTF_8);
+            }
             if (placeholder.startsWith("bundlebee-base64:")) {
                 return Base64.getEncoder().encodeToString(placeholder.substring("bundlebee-base64:".length()).getBytes(StandardCharsets.UTF_8));
             }
+            if (placeholder.startsWith("bundlebee-base64-decode:")) {
+                return new String(Base64.getDecoder().decode(placeholder.substring("bundlebee-base64-decode:".length()).getBytes(StandardCharsets.UTF_8)), StandardCharsets.UTF_8);
+            }
             if (placeholder.startsWith("bundlebee-quote-escaped-inline-file:")) {
                 final var resource = readResource(placeholder, "bundlebee-quote-escaped-inline-file:");
                 return resource == null ? null : new String(resource, StandardCharsets.UTF_8)

bundlebee-core/src/test/java/io/yupiik/bundlebee/core/lang/SubstitutorProducerTest.java

@@ -219,6 +219,13 @@ void base64() {
                 substitutor.getOrDefault("bundlebee-base64:content", "failed"));
     }
 
+    @Test
+    void debase64() {
+        assertEquals(
+                "content",
+                substitutor.getOrDefault("bundlebee-base64-decode:" + Base64.getEncoder().encodeToString("content".getBytes(StandardCharsets.UTF_8)), "failed"));
+    }
+
     @Test
     void base64File(@TempDir final Path root) throws IOException {
         final var file = root.resolve("test.txt");

bundlebee-documentation/src/main/minisite/content/how-it-works.adoc

@@ -194,7 +194,9 @@ Placeholders can use some keywords to get some particular values:
 - `bundlebee-indent:<indent size>:<value>`: indents a value with the provided space size, it is generally combined with another interpolation (file ones in particular) as value, ex `{{bundlebee-indent:8:{{bundlebee-inline-file:myfile.txt}}}}`,
 - `bundlebee-inline-file:<file path>`: load the file content as value,
 - `bundlebee-base64-file:<file path>`: converts the file in base64 (useful to write `data:xxxx,<base64>` values for ex keeping the raw file in the filesystem, very helpful for images),
+- `bundlebee-base64-decode-file:<file path>`: decode the file from a base64 content,
 - `bundlebee-base64:<text>`: encodes in base64 the text,
+- `bundlebee-base64-decode:<text>`: decode from base64 to text the value `text`,
 - `bundlebee-digest:BASE64|HEX,<algorithm>,<text>`: computes the digest of the text encoded in base64 or hexa format (useful to read files like `ConfigMap` or `Secret` and inject their digest value in a `Deployment` annotations to force its reload for example),
 - `bundlebee-quote-escaped-inline-file:<file path>`: load the file content as a quoted value,
 - `bundlebee-json-inline-file:<file path>`: load the file content as a JSON string value - without quotes,