Introduction

Astu is CLI tool for running commands and debugging connectivity at scale.

Quickstart

Resolve targets

DNS queries return all IPs that are found:

astu resolve -T something.com
104.21.59.206
172.67.183.168

Ports are also supported and preserved:

astu resolve -T localhost:22
127.0.0.1:22

Ping targets

astu ping -T localhost:22

Architecture

Targets

A target is the basic unit of operation in Astu - it represents an object on which an action will be performed.

Targets are usually parsed from URIs, but they also support convenient short forms for common types. Not all target types support short forms; those that do will state so.

Here is an example long form for an IP target:

ip://127.0.0.1

While here is the equivalent short form for the same target:

127.0.0.1

Targets can be dynamically expanded and aggregated into other targets using resolvers. The core Astu workflow revolves around dynamic target discovery using resolvers. Generally, one provides at least one seed target which is iteratively expanded using resolver chains.

Clients are drivers that perform actions on targets.

Target Graph

A target graph is special target-centric data structure representing targets as a directed graph. Resolvers generally support resolving directly into a caller-provided target graph - this is useful for building a topological action plan.

Here's a simple example of the target graph for a DNS target that resolves to multiple different IP targets:

While here's a more complex example where targets have multiple parents. In this example, both the CIDR target 10.0.0.0/31 and the DNS target myrouter.lan point to the IP target 10.0.0.1.

Target Types

For each target type, the URI and short forms will be given along with some examples.

IP

Internet Protocol (IP) address.

• URI form: ip://[user@]<ip>[:port]
  • ip://127.0.0.1
  • ip://root@127.0.0.1:22
  • ip://[::1]
  • ip://root@[::1]:22
• Short form: <ip>[:port]
  • 127.0.0.1
  • 127.0.0.1:22
  • ::1
  • [::1]:22

TCP

Essentially an alias for IP.

CIDR

Classless Inter-Domain Routing (CIDR) block.

• URI form: cidr://[user@]<ip>[:port]/<prefix>
  • cidr://127.0.0.0/32
  • cidr://root@127.0.0.0:22/32
  • cidr://[::1]/128
  • cidr://root@[::1]:22/128
• Short form: <ip>/<prefix>
  • 127.0.0.0/24
  • ::1/128

DNS

Domain Name System (DNS) record.

• URI form: dns://[user@]<name>[:port]
  • dns://localhost
  • dns://root@localhost:22
• Short form: n/a

SSH

Secure Shell (SSH) address.

• URI form: ssh://[user@]<host>[:port]
  • ssh://127.0.0.1
  • ssh://localhost
  • ssh://root@localhost:2222
• Short form: n/a

File

Local file.

• URI form: file:[//]<path>
  • file:///absolute/file.txt
  • file://relative/file.txt
  • file:relative/file.txt
• Short form: <path> (if path exists locally)
  • /absolute/file.txt
  • relative/file.txt

Kubernetes

Kubernetes pod.

• URI form: k8s:[//][user@][cluster][/namespace]/<name>[#container][?kind]
  • k8s:coredns-ff8999cc5-x56jw
  • k8s:kube-system/coredns#coredns?deployment
  • k8s://user@cluster/kube-system/coredns#coredns?deployment
• Short form: n/a

Developing

Project Structure

CLI

The astu command line interface. Parses flags and loads configuration.

Library

Core logic: types and drivers for target resolution and action execution.

Coding Style

Commit Messages

Uses pre-commit for enforcing Conventional Commits. This is used for automating the release process.

Initialize pre-commit's Git hooks in this repo after first clone:

pre-commit install

Release

Inspired by this post. Uses conventional commits for automatically bumping versions.

TODOs

• Eliminate all usages of dyn in favor of enum_dispatch
• Eliminate all usages of async_trait for more readable documentation
• Investigate if internment is really necessary for the target graph
• Investigate why release PRs are being made even though no Rust changes have been made