feat: added serialization for k8s config (#266)

Added serialization to `K8Config` and an ability to save changes to the original file.

This is needed for adding the embedded k8s context to the kube context file.

src/k8-config/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "k8-config"
-version = "2.1.0"
+version = "2.2.0"
 authors = ["Fluvio Contributors <team@fluvio.io>"]
 edition = "2021"
 description = "Read Kubernetes config"
@@ -25,4 +25,4 @@ fluvio-future = { workspace = true, features = ["subscriber"]}
 
 
 [[example]]
-name = "kubeconfig_read"
+name = "kubeconfig_read"

src/k8-config/src/config.rs

@@ -2,24 +2,29 @@ use std::fs::read_to_string;
 use std::fs::File;
 use std::io::Result as IoResult;
 use std::path::Path;
+use std::path::PathBuf;
 
 use dirs::home_dir;
 use serde::Deserialize;
+use serde::Serialize;
 use serde_json::Value;
 
 use crate::ConfigError;
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Serialize, Deserialize)]
 pub struct Cluster {
     pub name: String,
     pub cluster: ClusterDetail,
 }
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Default, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub struct ClusterDetail {
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub insecure_skip_tls_verify: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub certificate_authority: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub certificate_authority_data: Option<String>,
     pub server: String,
 }
@@ -30,16 +35,17 @@ impl ClusterDetail {
     }
 }
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Serialize, Deserialize)]
 pub struct Context {
     pub name: String,
     pub context: ContextDetail,
 }
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Default, Serialize, Deserialize)]
 pub struct ContextDetail {
     pub cluster: String,
     pub user: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub namespace: Option<String>,
 }
 
@@ -52,7 +58,7 @@ impl ContextDetail {
     }
 }
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Serialize, Deserialize)]
 pub struct User {
     pub name: String,
     pub user: UserDetail,
@@ -64,7 +70,7 @@ pub struct User {
 //    pub config: HashMap<String, String>,
 //}
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Serialize, Deserialize)]
 #[serde(tag = "name", content = "config")]
 pub enum AuthProviderDetail {
     #[serde(alias = "gcp")]
@@ -101,12 +107,14 @@ impl AuthProviderDetail {
     }
 }
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub struct GcpAuthProviderConfig {
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub access_token: Option<String>,
     pub cmd_args: String,
     pub cmd_path: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub expiry: Option<String>,
     pub expiry_key: String,
     pub token_key: String,
@@ -123,21 +131,30 @@ pub struct GcpAuthProviderConfig {
 //    refresh_token: String,
 //}
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Default, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub struct UserDetail {
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub auth_provider: Option<AuthProviderDetail>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub client_certificate: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub client_key: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub client_certificate_data: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub client_key_data: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub exec: Option<Exec>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub token: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub username: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub password: Option<String>,
 }
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub struct Exec {
     #[serde(rename = "apiVersion")]
@@ -146,9 +163,11 @@ pub struct Exec {
     pub command: String,
 }
 
-#[derive(Debug, Eq, PartialEq, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Default, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub struct KubeConfig {
+    #[serde(skip)]
+    pub path: PathBuf,
     #[serde(rename = "apiVersion")]
     pub api_version: String,
     pub clusters: Vec<Cluster>,
@@ -166,8 +185,19 @@ impl KubeConfig {
     }
 
     pub fn from_file<T: AsRef<Path>>(path: T) -> Result<Self, ConfigError> {
-        let file = File::open(path)?;
-        Ok(serde_yaml::from_reader(file)?)
+        let file = File::open(path.as_ref())?;
+        let mut config: Self = serde_yaml::from_reader(file)?;
+        config.path = path.as_ref().to_path_buf();
+        Ok(config)
+    }
+
+    pub fn to_file<T: AsRef<Path>>(&self, path: T) -> Result<(), ConfigError> {
+        let file = File::create(path)?;
+        Ok(serde_yaml::to_writer(file, self)?)
+    }
+
+    pub fn save(&self) -> Result<(), ConfigError> {
+        self.to_file(&self.path)
     }
 
     pub fn current_context(&self) -> Option<&Context> {
@@ -191,11 +221,46 @@ impl KubeConfig {
             None
         }
     }
+
+    pub fn put_user(&mut self, user: User) -> Option<User> {
+        let prev = self.users.iter_mut().find(|u| u.name.eq(&user.name));
+        match prev {
+            Some(prev) => Some(std::mem::replace(prev, user)),
+            None => {
+                self.users.push(user);
+                None
+            }
+        }
+    }
+
+    pub fn put_cluster(&mut self, cluster: Cluster) -> Option<Cluster> {
+        let prev = self.clusters.iter_mut().find(|c| c.name.eq(&cluster.name));
+        match prev {
+            Some(prev) => Some(std::mem::replace(prev, cluster)),
+            None => {
+                self.clusters.push(cluster);
+                None
+            }
+        }
+    }
+
+    pub fn put_context(&mut self, context: Context) -> Option<Context> {
+        let prev = self.contexts.iter_mut().find(|c| c.name.eq(&context.name));
+        match prev {
+            Some(prev) => Some(std::mem::replace(prev, context)),
+            None => {
+                self.contexts.push(context);
+                None
+            }
+        }
+    }
 }
 
 #[cfg(test)]
 mod test {
 
+    use crate::{User, Cluster, Context};
+
     use super::KubeConfig;
 
     #[test]
@@ -219,4 +284,147 @@ mod test {
         let current_cluster = config.current_cluster().expect("current");
         assert_eq!(current_cluster.name, "minikube");
     }
+
+    #[test]
+    fn test_config_ser() {
+        //given
+        let config = KubeConfig::from_file("data/k8config.yaml").expect("read");
+
+        //when
+        let serialized = serde_yaml::to_string(&config).expect("serialized");
+
+        //then
+        assert_eq!(
+            serialized,
+            r#"apiVersion: v1
+clusters:
+- name: minikube
+  cluster:
+    certificate-authority: /Users/test/.minikube/ca.crt
+    server: https://192.168.0.0:8443
+contexts:
+- name: flv
+  context:
+    cluster: minikube
+    user: minikube
+    namespace: flv
+- name: minikube
+  context:
+    cluster: minikube
+    user: minikube
+current-context: flv
+kind: Config
+users:
+- name: minikube
+  user:
+    client-certificate: /Users/test/.minikube/client.crt
+    client-key: /Users/test/.minikube/client.key
+"#
+        );
+    }
+
+    #[test]
+    fn test_put_user() {
+        //given
+        let mut config = KubeConfig::default();
+
+        let user1 = User {
+            name: "user1".to_string(),
+            user: crate::UserDetail {
+                username: Some("username1".to_string()),
+                ..Default::default()
+            },
+        };
+
+        let user1_2 = User {
+            name: "user1".to_string(),
+            user: crate::UserDetail {
+                username: Some("username2".to_string()),
+                ..Default::default()
+            },
+        };
+
+        let user2 = User {
+            name: "user2".to_string(),
+            user: Default::default(),
+        };
+
+        //when
+        assert!(config.put_user(user1).is_none());
+        assert!(config.put_user(user2).is_none());
+
+        let prev = config.put_user(user1_2);
+        assert!(prev.is_some());
+        assert_eq!(prev.unwrap().user.username.unwrap(), "username1");
+    }
+
+    #[test]
+    fn test_put_cluster() {
+        //given
+        let mut config = KubeConfig::default();
+
+        let cluster1 = Cluster {
+            name: "cluster1".to_string(),
+            cluster: crate::ClusterDetail {
+                server: "server1".to_string(),
+                ..Default::default()
+            },
+        };
+
+        let cluster1_2 = Cluster {
+            name: "cluster1".to_string(),
+            cluster: crate::ClusterDetail {
+                server: "server2".to_string(),
+                ..Default::default()
+            },
+        };
+
+        let cluster2 = Cluster {
+            name: "cluster2".to_string(),
+            cluster: Default::default(),
+        };
+
+        //when
+        assert!(config.put_cluster(cluster1).is_none());
+        assert!(config.put_cluster(cluster2).is_none());
+
+        let prev = config.put_cluster(cluster1_2);
+        assert!(prev.is_some());
+        assert_eq!(prev.unwrap().cluster.server, "server1");
+    }
+
+    #[test]
+    fn test_put_context() {
+        //given
+        let mut config = KubeConfig::default();
+
+        let context1 = Context {
+            name: "context1".to_string(),
+            context: crate::ContextDetail {
+                cluster: "cluster1".to_string(),
+                ..Default::default()
+            },
+        };
+
+        let context1_2 = Context {
+            name: "context1".to_string(),
+            context: crate::ContextDetail {
+                cluster: "cluster2".to_string(),
+                ..Default::default()
+            },
+        };
+
+        let context2 = Context {
+            name: "context2".to_string(),
+            context: Default::default(),
+        };
+
+        //when
+        assert!(config.put_context(context1).is_none());
+        assert!(config.put_context(context2).is_none());
+
+        let prev = config.put_context(context1_2);
+        assert!(prev.is_some());
+        assert_eq!(prev.unwrap().context.cluster, "cluster1");
+    }
 }