inital working commit

This commit is contained in:
Tamipes 2025-11-24 23:02:02 +01:00
commit 28109122b2
18 changed files with 3321 additions and 0 deletions

292
src/main.rs Normal file
View file

@ -0,0 +1,292 @@
//! This is a simple imitation of the basic functionality of kubectl:
//! kubectl {get, delete, apply, watch, edit} <resource> [name]
//! with labels and namespace selectors supported.
use anyhow::{bail, Context, Result};
use futures::{StreamExt, TryStreamExt};
use k8s_openapi::{
api::apps::v1::Deployment, apimachinery::pkg::apis::meta::v1::Time, chrono::Utc,
};
use kube::{
api::{Api, DynamicObject, ListParams, Patch, PatchParams, ResourceExt},
core::GroupVersionKind,
discovery::{ApiCapabilities, ApiResource, Discovery, Scope},
runtime::{
wait::{await_condition, conditions::is_deleted},
watcher, WatchStreamExt,
},
Client,
};
use tracing::*;
mod packets;
mod types;
#[derive(clap::Parser)]
struct App {
#[arg(long, short, default_value_t = OutputMode::Pretty)]
output: OutputMode,
#[arg(long, short)]
file: Option<std::path::PathBuf>,
#[arg(long, short = 'l')]
selector: Option<String>,
#[arg(long, short)]
namespace: Option<String>,
#[arg(long, short = 'A')]
all: bool,
verb: Verb,
resource: Option<String>,
name: Option<String>,
}
#[derive(Clone, PartialEq, Eq, clap::ValueEnum)]
enum OutputMode {
Pretty,
Yaml,
}
impl OutputMode {
fn as_str(&self) -> &'static str {
match self {
Self::Pretty => "pretty",
Self::Yaml => "yaml",
}
}
}
impl std::fmt::Display for OutputMode {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.pad(self.as_str())
}
}
#[derive(Clone, PartialEq, Eq, Debug, clap::ValueEnum)]
enum Verb {
Get,
Delete,
Edit,
Watch,
Apply,
}
fn resolve_api_resource(
discovery: &Discovery,
name: &str,
) -> Option<(ApiResource, ApiCapabilities)> {
// iterate through groups to find matching kind/plural names at recommended versions
// and then take the minimal match by group.name (equivalent to sorting groups by group.name).
// this is equivalent to kubectl's api group preference
discovery
.groups()
.flat_map(|group| {
group
.resources_by_stability()
.into_iter()
.map(move |res| (group, res))
})
.filter(|(_, (res, _))| {
// match on both resource name and kind name
// ideally we should allow shortname matches as well
name.eq_ignore_ascii_case(&res.kind) || name.eq_ignore_ascii_case(&res.plural)
})
.min_by_key(|(group, _res)| group.name())
.map(|(_, res)| res)
}
impl App {
async fn get(&self, api: Api<DynamicObject>, lp: ListParams) -> Result<()> {
let mut result: Vec<_> = if let Some(n) = &self.name {
vec![api.get(n).await?]
} else {
api.list(&lp).await?.items
};
result
.iter_mut()
.for_each(|x| x.managed_fields_mut().clear()); // hide managed fields
match self.output {
OutputMode::Yaml => println!("{}", serde_yaml::to_string(&result)?),
OutputMode::Pretty => {
// Display style; size columns according to longest name
let max_name = result
.iter()
.map(|x| x.name_any().len() + 2)
.max()
.unwrap_or(63);
println!("{0:<width$} {1:<20}", "NAME", "AGE", width = max_name);
for inst in result {
let age = inst
.creation_timestamp()
.map(format_creation)
.unwrap_or_default();
println!(
"{0:<width$} {1:<20}",
inst.name_any(),
age,
width = max_name
);
}
}
}
Ok(())
}
async fn delete(&self, api: Api<DynamicObject>, lp: ListParams) -> Result<()> {
if let Some(n) = &self.name {
if let either::Either::Left(pdel) = api.delete(n, &Default::default()).await? {
// await delete before returning
await_condition(api, n, is_deleted(&pdel.uid().unwrap())).await?;
}
} else {
api.delete_collection(&Default::default(), &lp).await?;
}
Ok(())
}
async fn watch(&self, api: Api<DynamicObject>, mut wc: watcher::Config) -> Result<()> {
if let Some(n) = &self.name {
wc = wc.fields(&format!("metadata.name={n}"));
}
// present a dumb table for it for now. kubectl does not do this anymore.
let mut stream = watcher(api, wc).applied_objects().boxed();
println!("{0:<width$} {1:<20}", "NAME", "AGE", width = 63);
while let Some(inst) = stream.try_next().await? {
let age = inst
.creation_timestamp()
.map(format_creation)
.unwrap_or_default();
println!("{0:<width$} {1:<20}", inst.name_any(), age, width = 63);
}
Ok(())
}
async fn edit(&self, api: Api<DynamicObject>) -> Result<()> {
if let Some(n) = &self.name {
let mut orig = api.get(n).await?;
orig.managed_fields_mut().clear(); // hide managed fields
let input = serde_yaml::to_string(&orig)?;
debug!("opening {} in {:?}", orig.name_any(), edit::get_editor());
let edited = edit::edit(&input)?;
if edited != input {
info!("updating changed object {}", orig.name_any());
let data: DynamicObject = serde_yaml::from_str(&edited)?;
// NB: simplified kubectl constructs a merge-patch of differences
api.replace(n, &Default::default(), &data).await?;
}
} else {
warn!("need a name to edit");
}
Ok(())
}
async fn apply(&self, client: Client, discovery: &Discovery) -> Result<()> {
let ssapply = PatchParams::apply("kubectl-light").force();
let pth = self.file.clone().expect("apply needs a -f file supplied");
let yaml = std::fs::read_to_string(&pth)
.with_context(|| format!("Failed to read {}", pth.display()))?;
for doc in multidoc_deserialize(&yaml)? {
let obj: DynamicObject = serde_yaml::from_value(doc)?;
let namespace = obj
.metadata
.namespace
.as_deref()
.or(self.namespace.as_deref());
let gvk = if let Some(tm) = &obj.types {
GroupVersionKind::try_from(tm)?
} else {
bail!("cannot apply object without valid TypeMeta {:?}", obj);
};
let name = obj.name_any();
if let Some((ar, caps)) = discovery.resolve_gvk(&gvk) {
let api = dynamic_api(ar, caps, client.clone(), namespace, false);
trace!("Applying {}: \n{}", gvk.kind, serde_yaml::to_string(&obj)?);
let data: serde_json::Value = serde_json::to_value(&obj)?;
let _r = api.patch(&name, &ssapply, &Patch::Apply(data)).await?;
info!("applied {} {}", gvk.kind, name);
} else {
warn!("Cannot apply document for unknown {:?}", gvk);
}
}
Ok(())
}
}
#[tokio::main]
async fn main() -> Result<()> {
tracing_subscriber::fmt::init();
// let app: App = clap::Parser::parse();
let kubeconfig = kube::config::Kubeconfig::read()?;
let client = Client::try_from(kubeconfig)?;
let deployments: Api<Deployment> = Api::default_namespaced(client);
let lp: ListParams = ListParams::default();
println!("{:?}", deployments.list(&lp).await?);
// // discovery (to be able to infer apis from kind/plural only)
// let discovery = Discovery::new(client.clone()).run().await?;
// // Defer to methods for verbs
// if let Some(resource) = &app.resource {
// // Common discovery, parameters, and api configuration for a single resource
// let (ar, caps) = resolve_api_resource(&discovery, resource)
// .with_context(|| format!("resource {resource:?} not found in cluster"))?;
// let mut lp = ListParams::default();
// if let Some(label) = &app.selector {
// lp = lp.labels(label);
// }
// let mut wc = watcher::Config::default();
// if let Some(label) = &app.selector {
// wc = wc.labels(label);
// }
// let api = dynamic_api(ar, caps, client, app.namespace.as_deref(), app.all);
// tracing::info!(?app.verb, ?resource, name = ?app.name.clone().unwrap_or_default(), "requested objects");
// match app.verb {
// Verb::Edit => app.edit(api).await?,
// Verb::Get => app.get(api, lp).await?,
// Verb::Delete => app.delete(api, lp).await?,
// Verb::Watch => app.watch(api, wc).await?,
// Verb::Apply => bail!("verb {:?} cannot act on an explicit resource", app.verb),
// }
// } else if app.verb == Verb::Apply {
// app.apply(client, &discovery).await? // multi-resource special behaviour
// }
Ok(())
}
fn dynamic_api(
ar: ApiResource,
caps: ApiCapabilities,
client: Client,
ns: Option<&str>,
all: bool,
) -> Api<DynamicObject> {
if caps.scope == Scope::Cluster || all {
Api::all_with(client, &ar)
} else if let Some(namespace) = ns {
Api::namespaced_with(client, namespace, &ar)
} else {
Api::default_namespaced_with(client, &ar)
}
}
fn format_creation(time: Time) -> String {
let dur = Utc::now().signed_duration_since(time.0);
match (dur.num_days(), dur.num_hours(), dur.num_minutes()) {
(days, _, _) if days > 0 => format!("{days}d"),
(_, hours, _) if hours > 0 => format!("{hours}h"),
(_, _, mins) => format!("{mins}m"),
}
}
pub fn multidoc_deserialize(data: &str) -> Result<Vec<serde_yaml::Value>> {
use serde::Deserialize;
let mut docs = vec![];
for de in serde_yaml::Deserializer::from_str(data) {
docs.push(serde_yaml::Value::deserialize(de)?);
}
Ok(docs)
}