refactor 'latest_release' and address PR feedback

Author: labrenbe

Cargo.lock

@@ -21,6 +21,9 @@ Options:
           Cached files are saved at '$XDG_CACHE_HOME/stackablectl', which is usually
           '$HOME/.cache/stackablectl' when not explicitly set.
 
+      --release <RELEASE>
+          Target a specific Stackable release
+
   -h, --help
           Print help (see a summary with '-h')
 

Cargo.nix

@@ -20,6 +20,7 @@ indexmap.workspace = true
 k8s-openapi.workspace = true
 kube.workspace = true
 rand.workspace = true
+regex.workspace = true
 reqwest.workspace = true
 semver.workspace = true
 serde_json.workspace = true

docs/modules/stackablectl/partials/commands/stack.adoc

@@ -1,7 +1,8 @@
 use futures::{StreamExt as _, TryStreamExt};
 use indexmap::IndexMap;
+use regex::Regex;
 use serde::{Deserialize, Serialize};
-use snafu::{ResultExt, Snafu};
+use snafu::{OptionExt, ResultExt, Snafu};
 use tokio::task::JoinError;
 use tracing::{info, instrument};
 
@@ -16,6 +17,8 @@ use crate::{
     },
 };
 
+use super::ReleaseList;
+
 type Result<T, E = Error> = std::result::Result<T, E>;
 
 #[derive(Debug, Snafu)]
@@ -31,6 +34,12 @@ pub enum Error {
 
     #[snafu(display("failed to launch background task"))]
     BackgroundTask { source: JoinError },
+
+    #[snafu(display("release list is empty"))]
+    EmptyReleaseList,
+
+    #[snafu(display("latest release doesn't have expected format"))]
+    LatestReleaseFormat,
 }
 
 #[derive(Clone, Debug, Deserialize, Serialize)]
@@ -119,3 +128,16 @@ impl ReleaseSpec {
             .collect()
     }
 }
+
+impl ReleaseList {
+    /// Retrieves the latest release from the list and applies a sanity check to the release format.
+    pub fn latest_release(&self) -> Result<String, Error> {
+        let release = self.inner().first().context(EmptyReleaseListSnafu)?.0;
+        let sanity_check = Regex::new("^[0-9]{2}.[0-9]{1,2}$").unwrap();
+        if sanity_check.is_match(release) {
+            Ok(release.to_string())
+        } else {
+            LatestReleaseFormatSnafu {}.fail()
+        }
+    }
+}