Adds validation methods for well-formed names

Cargo.toml

@@ -6,11 +6,14 @@ edition = "2018"
 
 [dependencies]
 async-trait = "0.1"
-either = "1.6"
+const_format = "0.2"
+either = "1"
 futures = "0.3"
 k8s-openapi = { version = "0.11", default-features = false }
 kube = { version = "0.49", default-features = false, features = ["derive"] }
 kube-runtime = "0.49"
+lazy_static = "1"
+regex = "1"
 serde = "1.0"
 serde_json = "1.0"
 serde_yaml = "0.8"

src/lib.rs

@@ -9,6 +9,7 @@ pub mod k8s_errors;
 pub mod metadata;
 pub mod podutils;
 pub mod reconcile;
+pub mod validation;
 
 use crate::error::OperatorResult;
 

src/validation.rs

@@ -0,0 +1,143 @@
+// See apimachinery/pkg/util/validation/validation.go
+// See also TODO apimachinery/pkg/api/validation/generic.go and pkg/apis/core/validation/validation.go
+
+use const_format::concatcp;
+use lazy_static::lazy_static;
+use regex::Regex;
+
+const RFC_1123_LABEL_FMT: &str = "[a-z0-9]([-a-z0-9]*[a-z0-9])?";
+const RFC_1123_SUBDOMAIN_FMT: &str =
+ concatcp!(RFC_1123_LABEL_FMT, "(\\.", RFC_1123_LABEL_FMT, ")*");
+const RFC_1123_SUBDOMAIN_ERROR_MSG: &str = "a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character";
+
+// This is a subdomain's max length in DNS (RFC 1123)
+const RFC_1123_SUBDOMAIN_MAX_LENGTH: usize = 253;
+
+lazy_static! {
+ static ref RFC_1123_SUBDOMAIN_REGEX: Regex =
+ Regex::new(&format!("^{}$", RFC_1123_SUBDOMAIN_FMT)).unwrap();
+}
+
+/// Returns a formatted error message for maximum length violations.
+fn max_len_error(length: usize) -> String {
+ format!("must be no more than {} characters", length)
+}
+
+/// Returns a formatted error message for regex violations.
+///
+/// # Arguments
+///
+/// * `msg` - this is the main error message to return
+/// * `fmt` - this is the regular expression that did not match the input
+/// * `examples` - are optional well, formed examples that would match the regex
+fn regex_error(msg: &str, fmt: &str, examples: &[&str]) -> String {
+ if examples.is_empty() {
+ return format!("{} (regex used for validation is '{}')", msg, fmt);
+ }
+
+ let mut msg = msg.to_string();
+ msg.push_str(" (e.g. ");
+ for (i, example) in examples.iter().enumerate() {
+ if i > 0 {
+ msg.push_str(" or ");
+ }
+ msg.push('\'');
+ msg.push_str(example);
+ msg.push_str("', ");
+ }
+
+ msg.push_str("regex used for validation is '");
+ msg.push_str(&fmt);
+ msg.push_str("')");
+ msg
+}
+
+pub fn is_rfc_1123_subdomain(value: &str) -> Vec<String> {
+ let mut errors = vec![];
+ if value.len() > RFC_1123_SUBDOMAIN_MAX_LENGTH {
+ errors.push(max_len_error(RFC_1123_SUBDOMAIN_MAX_LENGTH))
+ }
+
+ if !RFC_1123_SUBDOMAIN_REGEX.is_match(value) {
+ errors.push(regex_error(
+ RFC_1123_SUBDOMAIN_ERROR_MSG,
+ RFC_1123_SUBDOMAIN_FMT,
+ &["example.com"],
+ ))
+ }
+
+ errors
+}
+
+// mask_trailing_dash replaces the final character of a string with a subdomain safe
+// value if is a dash.
+fn mask_trailing_dash(mut name: String) -> String {
+ if name.ends_with('-') {
+ name.pop();
+ name.push('a');
+ }
+
+ name
+}
+
+/// name_is_dns_subdomain checks whether the passed in name is a valid
+/// DNS subdomain name
+///
+/// # Arguments
+///
+/// * `name` - is the name to check for validity
+/// * `prefix` - indicates whether `name` is just a prefix (ending in a dash, which would otherwise not be legal at the end)
+pub fn name_is_dns_subdomain(name: &str, prefix: bool) -> Vec<String> {
+ let mut name = name.to_string();
+ if prefix {
+ name = mask_trailing_dash(name);
+ }
+
+ is_rfc_1123_subdomain(&name)
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use rstest::rstest;
+
+ #[rstest(
+ value,
+ case(""), case("A"), case("ABC"), case("aBc"), case("A1"), case("A-1"), case("1-A"),
+ case("-"), case("a-"), case("-a"), case("1-"), case("-1"), case("_"), case("a_"),
+ case("_a"), case("a_b"), case("1_"), case("_1"), case("1_2"), case("."), case("a."),
+ case(".a"), case("a..b"), case("1."), case(".1"), case("1..2"), case(" "), case("a "),
+ case(" a"), case("a b"), case("1 "), case(" 1"), case("1 2"), case("A.a"), case("aB.a"),
+ case("ab.A"), case("A1.a"), case("a1.A"), case("A.1"), case("aB.1"), case("A1.1"),
+ case("1A.1"), case("0.A"), case("01.A"), case("012.A"), case("1A.a"), case("1a.A"),
+ case("A.B.C.D.E"), case("AA.BB.CC.DD.EE"), case("a.B.c.d.e"), case("aa.bB.cc.dd.ee"),
+ case("a@b"), case("a,b"), case("a_b"), case("a;b"), case("a:b"), case("a%b"), case("a?b"),
+ case("a$b"), case(&"a".repeat(254))
+ )]
+ fn test_bad_values_is_rfc_1123_subdomain(value: &str) {
+ assert!(!is_rfc_1123_subdomain(value).is_empty());
+ }
+
+ #[rstest(
+ value,
+ case("a"), case("ab"), case("abc"), case("a1"), case("a-1"), case("a--1--2--b"), case("0"),
+ case("01"), case("012"), case("1a"), case("1-a"), case("1--a--b--2"), case("a.a"),
+ case("ab.a"), case("abc.a"), case("a1.a"), case("a-1.a"), case("a--1--2--b.a"), case("a.1"),
+ case("ab.1"), case("abc.1"), case("a1.1"), case("a-1.1"), case("a--1--2--b.1"), case("0.a"),
+ case("01.a"), case("012.a"), case("1a.a"), case("1-a.a"), case("1--a--b--2"), case("0.1"),
+ case("01.1"), case("012.1"), case("1a.1"), case("1-a.1"), case("1--a--b--2.1"),
+ case("a.b.c.d.e"), case("aa.bb.cc.dd.ee"), case("1.2.3.4.5"), case("11.22.33.44.55"),
+ case(&"a".repeat(253))
+ )]
+ fn test_good_values_is_rfc_1123_subdomain(value: &str) {
+ assert!(is_rfc_1123_subdomain(value).is_empty());
+ }
+
+ #[test]
+ fn test_mask_trailing_dash() {
+ assert_eq!(mask_trailing_dash("abc-".to_string()), "abca");
+ assert_eq!(mask_trailing_dash("abc".to_string()), "abc");
+ assert_eq!(mask_trailing_dash(String::new()), String::new());
+ assert_eq!(mask_trailing_dash("-".to_string()), "a");
+ }
+}