{"id":11919,"date":"2025-10-07T21:49:45","date_gmt":"2025-10-07T21:49:45","guid":{"rendered":"https:\/\/putridparrot.com\/blog\/?p=11919"},"modified":"2025-10-07T21:49:45","modified_gmt":"2025-10-07T21:49:45","slug":"creating-kubectl-plugins","status":"publish","type":"post","link":"https:\/\/putridparrot.com\/blog\/creating-kubectl-plugins\/","title":{"rendered":"Creating kubectl plugins"},"content":{"rendered":"

To create a kubectl plugin whereby, for example, we could rung a new tool like this<\/p>\n

\r\nkubectl log index echo 3 -n dev\r\n<\/pre>\n
Where the above would find pods with a partial name of echo<\/em> and from those pods that match, finds the index 3 (0 indexed).<\/p>\n
To create a plugin you use the naming convention <\/p>\n
\r\nkubeclt-<your-plugin-name>\r\n<\/pre>\n
You need to build your plugin then ensure it’s copied into your PATH.<\/p>\n
Once built and copied, you can use the following to check if kubectl can find the plugin<\/p>\n
\r\nkubectl plugin list\r\n<\/pre>\n
Sample Plugin<\/strong><\/p>\n
I’ve created the plugin using Rust.<\/p>\n
Note: This is just a quick implementation and not fully tested, but gives an idea of how to create such a plugin.<\/em><\/p>\n
Set your Cargo.toml dependencies as follows<\/p>\n
\r\nk8s-openapi = { version = "0.26.0", features = ["v1_32"] }\r\nkube = { version = "2.0.1", features = ["runtime", "derive"] }\r\ntokio = { version = "1", features = ["full"] }\r\nclap = { version = "4", features = ["derive"] }\r\nanyhow = "1.0"\r\n<\/pre>\n
Next we want to create the command line arguments using the following<\/p>\n
\r\n#[derive(Parser, Debug)]\r\n#[command(name = "kubectl-log-index")]\r\n#[command(author, version, about)]\r\npub struct Args {\r\n    \/\/\/ Partial name of the pod to match\r\n    #[arg()]\r\n    pub pod_part: String,\r\n    \/\/\/ Index of the pod (0-based)\r\n    pub index: usize,\r\n    \/\/\/ Follow the log stream\r\n    #[arg(short = 'f', long)]\r\n    pub follow: bool,\r\n    \/\/\/ Kubernetes namespace (optional)\r\n    #[arg(short, long)]\r\n    pub namespace: Option<String>,\r\n}\r\n<\/pre>\n
We’re supplying some short form parameters such as -f which can be used instead of –follow, likewise -n in place of –namespace.<\/p>\n
Our main.rs looks like this<\/p>\n
\r\nmod args;\r\n\r\nuse clap::Parser;\r\nuse anyhow::Result;\r\nuse kube::{Api, Client};\r\nuse k8s_openapi::api::core::v1::Pod;\r\nuse std::process::Command;\r\nuse kube::api::ListParams;\r\nuse kube::runtime::reflector::Lookup;\r\nuse crate::args::Args;\r\n\r\n\/\/\/ kubectl plugin to get logs by container index\r\n#[tokio::main]\r\nasync fn main() -> Result<()> {\r\n    let args = Args::parse();\r\n\r\n    let namespace: &str = args.namespace\r\n        .as_deref()\r\n        .unwrap_or("default");\r\n\r\n    let client = Client::try_default().await?;\r\n    let pods: Api<Pod> = Api::namespaced(client, namespace);\r\n\r\n    let pod_list = find_matching_pods(pods, &args.pod_part).await.expect("Failed to find matching pods");\r\n    \r\n    let pod = pod_list\r\n        .get(args.index)\r\n        .cloned()\r\n        .ok_or_else(|| anyhow::anyhow!("Pod not found"))?;\r\n\r\n    let pod_name = &pod.name().ok_or_else(|| anyhow::anyhow!("Pod name not found"))?;\r\n\r\n    let mut cmd = Command::new("kubectl");\r\n\r\n    cmd.args(["logs", pod_name]);\r\n\r\n    if namespace != "default" {\r\n        cmd.args(["-n", namespace]);\r\n    }\r\n\r\n    if args.follow {\r\n        cmd.arg("-f");\r\n    }\r\n\r\n    cmd\r\n        .status()?;\r\n\r\n    Ok(())\r\n}\r\n\r\npub async fn find_matching_pods(\r\n    pods: Api<Pod>,\r\n    partial: &str,\r\n) -> Result<Vec<Pod>, Box<dyn std::error::Error>> {\r\n    let pod_list = pods.list(&ListParams::default()).await?;\r\n\r\n    let matches: Vec<Pod> = pod_list.items\r\n        .into_iter()\r\n        .filter(|pod| {\r\n            pod.metadata.name\r\n                .as_ref()\r\n                .map(|name| name.contains(partial))\r\n                .unwrap_or(false)\r\n        })\r\n        .collect();\r\n\r\n    Ok(matches)\r\n}\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"
To create a kubectl plugin whereby, for example, we could rung a new tool like this kubectl log index echo 3 -n dev Where the above would find pods with a partial name of echo and from those pods that match, finds the index 3 (0 indexed). To create a plugin you use the naming […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[760,191],"tags":[],"class_list":["post-11919","post","type-post","status-publish","format-standard","hentry","category-kubectl","category-rust"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/posts\/11919","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/comments?post=11919"}],"version-history":[{"count":1,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/posts\/11919\/revisions"}],"predecessor-version":[{"id":11920,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/posts\/11919\/revisions\/11920"}],"wp:attachment":[{"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/media?parent=11919"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/categories?post=11919"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/tags?post=11919"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}