feat: Vendor Hadoop XML / Java properties writer in framework

maltesander · claude · maltesander · commit eeeb836a941e · 2026-06-03T15:40:35.000+02:00
Replaces product-config's writer module. Lives in framework::writer and
renders hive-site.xml (Hadoop XML) and security.properties (Java properties),
matching product-config's output. Also scaffolds controller/build with
placeholders for the per-file builders.

Co-Authored-By: Claude Opus 4.8 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -20,6 +20,7 @@ const_format = "0.2"
 fnv = "1.0"
 futures = { version = "0.3", features = ["compat"] }
 indoc = "2.0"
+java-properties = "2.0"
 pin-project = "1.1"
 rstest = "0.26"
 semver = "1.0"
@@ -30,6 +31,7 @@ snafu = "0.9"
 strum = { version = "0.28", features = ["derive"] }
 tokio = { version = "1.52", features = ["full"] }
 tracing = "0.1"
+xml = "1.3"
 
 [patch."https://github.com/stackabletech/operator-rs.git"]
 stackable-operator = { git = "https://github.com/stackabletech//operator-rs.git", branch = "smooth-operator" }
diff --git a/rust/operator-binary/Cargo.toml b/rust/operator-binary/Cargo.toml
@@ -18,6 +18,7 @@ const_format.workspace = true
 fnv.workspace = true
 futures.workspace = true
 indoc.workspace = true
+java-properties.workspace = true
 pin-project.workspace = true
 semver.workspace = true
 serde.workspace = true
@@ -26,6 +27,7 @@ snafu.workspace = true
 strum.workspace = true
 tokio.workspace = true
 tracing.workspace = true
+xml.workspace = true
 
 [dev-dependencies]
 rstest.workspace = true
diff --git a/rust/operator-binary/src/controller.rs b/rust/operator-binary/src/controller.rs
@@ -2,6 +2,8 @@
 
 mod dereference;
 mod validate;
+#[allow(dead_code)] // wired up in a later task
+mod build;
 
 use std::{
     collections::{BTreeMap, HashMap},
diff --git a/rust/operator-binary/src/controller/build.rs b/rust/operator-binary/src/controller/build.rs
@@ -0,0 +1,4 @@
+//! Builders that turn a `ValidatedCluster` into Kubernetes resources.
+
+pub mod config_map;
+pub mod properties;
diff --git a/rust/operator-binary/src/controller/build/config_map.rs b/rust/operator-binary/src/controller/build/config_map.rs
@@ -0,0 +1 @@
+//! placeholder — implemented in a later task
diff --git a/rust/operator-binary/src/controller/build/properties.rs b/rust/operator-binary/src/controller/build/properties.rs
@@ -0,0 +1,5 @@
+//! Per-file builders for the Hive metastore config files.
+
+pub mod core_site;
+pub mod hive_site;
+pub mod security_properties;
diff --git a/rust/operator-binary/src/controller/build/properties/core_site.rs b/rust/operator-binary/src/controller/build/properties/core_site.rs
@@ -0,0 +1 @@
+//! placeholder — implemented in a later task
diff --git a/rust/operator-binary/src/controller/build/properties/hive_site.rs b/rust/operator-binary/src/controller/build/properties/hive_site.rs
@@ -0,0 +1 @@
+//! placeholder — implemented in a later task
diff --git a/rust/operator-binary/src/controller/build/properties/security_properties.rs b/rust/operator-binary/src/controller/build/properties/security_properties.rs
@@ -0,0 +1 @@
+//! placeholder — implemented in a later task
diff --git a/rust/operator-binary/src/framework.rs b/rust/operator-binary/src/framework.rs
@@ -11,3 +11,4 @@
 //! relaxes the `Merge` bound.
 
 pub mod role_utils;
+pub mod writer;
diff --git a/rust/operator-binary/src/framework/writer.rs b/rust/operator-binary/src/framework/writer.rs
@@ -0,0 +1,145 @@
+//! Writers for Hadoop XML config files and Java `.properties` files.
+//!
+//! Vendored from the `product-config` crate's `writer` module so the operator no
+//! longer depends on `product-config` for rendering.
+
+use std::io::Write;
+
+use java_properties::{PropertiesError, PropertiesWriter};
+use snafu::{ResultExt, Snafu};
+use xml::escape::escape_str_attribute;
+
+#[derive(Debug, Snafu)]
+pub enum PropertiesWriterError {
+    #[snafu(display("failed to create properties file"))]
+    Properties { source: PropertiesError },
+
+    #[snafu(display("failed to convert properties file byte array to UTF-8"))]
+    FromUtf8 { source: std::string::FromUtf8Error },
+}
+
+/// Creates a common Java properties file string in the format:
+/// `property_1=value_1\nproperty_2=value_2\n`.
+pub fn to_java_properties_string<'a, T>(properties: T) -> Result<String, PropertiesWriterError>
+where
+    T: Iterator<Item = (&'a String, &'a Option<String>)>,
+{
+    let mut output = Vec::new();
+    write_java_properties(&mut output, properties)?;
+    String::from_utf8(output).context(FromUtf8Snafu)
+}
+
+/// Writes Java properties to the given writer. A `None` value is written as an
+/// empty value (`key=`).
+fn write_java_properties<'a, W, T>(writer: W, properties: T) -> Result<(), PropertiesWriterError>
+where
+    W: Write,
+    T: Iterator<Item = (&'a String, &'a Option<String>)>,
+{
+    let mut writer = PropertiesWriter::new(writer);
+    for (k, v) in properties {
+        let property_value = v.as_deref().unwrap_or_default();
+        writer.write(k, property_value).context(PropertiesSnafu)?;
+    }
+    writer.flush().context(PropertiesSnafu)?;
+    Ok(())
+}
+
+/// Converts properties into a Hadoop configuration XML, including the wrapping
+/// `<configuration>...</configuration>` elements. Properties with a `None` value
+/// are skipped. Keys and values are XML-escaped.
+pub fn to_hadoop_xml<'a, T>(properties: T) -> String
+where
+    T: Iterator<Item = (&'a String, &'a Option<String>)>,
+{
+    let mut snippet = String::new();
+    for (k, v) in properties {
+        let escaped_value = match v {
+            Some(value) => escape_str_attribute(value),
+            None => continue,
+        };
+        let escaped_key = escape_str_attribute(k);
+        snippet.push_str(&format!(
+            "  <property>\n    <name>{escaped_key}</name>\n    <value>{escaped_value}</value>\n  </property>\n"
+        ));
+    }
+    format!("<?xml version=\"1.0\"?>\n<configuration>\n{snippet}</configuration>")
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::BTreeMap;
+
+    use super::*;
+
+    fn xml(pairs: &[(&str, Option<&str>)]) -> String {
+        let map: BTreeMap<String, Option<String>> = pairs
+            .iter()
+            .map(|(k, v)| (k.to_string(), v.map(str::to_string)))
+            .collect();
+        to_hadoop_xml(map.iter())
+    }
+
+    fn props(pairs: &[(&str, Option<&str>)]) -> String {
+        let map: BTreeMap<String, Option<String>> = pairs
+            .iter()
+            .map(|(k, v)| (k.to_string(), v.map(str::to_string)))
+            .collect();
+        to_java_properties_string(map.iter()).unwrap()
+    }
+
+    #[test]
+    fn hadoop_xml_wraps_empty_configuration() {
+        assert_eq!(
+            xml(&[]),
+            "<?xml version=\"1.0\"?>\n<configuration>\n</configuration>"
+        );
+    }
+
+    #[test]
+    fn hadoop_xml_renders_single_property() {
+        assert_eq!(
+            xml(&[("fs.defaultFS", Some("hdfs://hdfs/"))]),
+            "<?xml version=\"1.0\"?>\n<configuration>\n  \
+             <property>\n    <name>fs.defaultFS</name>\n    \
+             <value>hdfs://hdfs/</value>\n  </property>\n</configuration>"
+        );
+    }
+
+    #[test]
+    fn hadoop_xml_skips_none_values() {
+        assert_eq!(
+            xml(&[("kept", Some("1")), ("dropped", None)]),
+            "<?xml version=\"1.0\"?>\n<configuration>\n  \
+             <property>\n    <name>kept</name>\n    \
+             <value>1</value>\n  </property>\n</configuration>"
+        );
+    }
+
+    #[test]
+    fn hadoop_xml_escapes_special_characters() {
+        let rendered = xml(&[("k", Some("<a>&b"))]);
+        assert!(
+            rendered.contains("<value>&lt;a&gt;&amp;b</value>"),
+            "{rendered}"
+        );
+    }
+
+    #[test]
+    fn java_properties_renders_key_value() {
+        assert_eq!(props(&[("a", Some("1")), ("b", Some("2"))]), "a=1\nb=2\n");
+    }
+
+    #[test]
+    fn java_properties_renders_none_as_empty() {
+        assert_eq!(props(&[("none", None)]), "none=\n");
+    }
+
+    #[test]
+    fn java_properties_escapes_colon_in_value() {
+        assert_eq!(
+            props(&[("url", Some("file://this/location/file.abc"))]),
+            "url=file\\://this/location/file.abc\n"
+        );
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+//! placeholder — implemented in a later task`