feat(report): add dot report mode to output flows in Graphviz DOT…

… format (#582)

src/config.rs

@@ -45,6 +45,8 @@ pub enum Mode {
     Csv,
     /// Generate a JSON report for N cycles.
     Json,
+    /// Generate a Graphviz DOT file for N cycles.
+    Dot,
     /// Do not generate any tracing output for N cycles.
     Silent,
 }
@@ -498,7 +500,7 @@ impl TryFrom<(Args, &Platform)> for TrippyConfig {
         let dns_timeout = humantime::parse_duration(&dns_timeout)?;
         let max_rounds = match mode {
             Mode::Stream | Mode::Tui => None,
-            Mode::Pretty | Mode::Markdown | Mode::Csv | Mode::Json | Mode::Silent => {
+            Mode::Pretty | Mode::Markdown | Mode::Csv | Mode::Json | Mode::Dot | Mode::Silent => {
                 Some(report_cycles)
             }
         };

src/main.rs

@@ -208,6 +208,7 @@ fn run_frontend(
         Mode::Json => report::run_report_json(&traces[0], args.report_cycles, &resolver)?,
         Mode::Pretty => report::run_report_table_pretty(&traces[0], args.report_cycles, &resolver)?,
         Mode::Markdown => report::run_report_table_md(&traces[0], args.report_cycles, &resolver)?,
+        Mode::Dot => report::run_report_dot(&traces[0], args.report_cycles)?,
         Mode::Silent => report::run_report_silent(&traces[0], args.report_cycles)?,
     }
     Ok(())

src/report.rs

@@ -1,11 +1,16 @@
+use crate::backend::flows::FlowEntry;
 use crate::backend::trace::Trace;
 use crate::TraceInfo;
 use anyhow::anyhow;
 use comfy_table::presets::{ASCII_MARKDOWN, UTF8_FULL};
 use comfy_table::{ContentArrangement, Table};
 use itertools::Itertools;
 use parking_lot::RwLock;
+use petgraph::dot::{Config, Dot};
+use petgraph::graphmap::DiGraphMap;
 use serde::{Serialize, Serializer};
+use std::fmt::{Debug, Formatter};
+use std::net::{IpAddr, Ipv4Addr};
 use std::sync::Arc;
 use std::thread::sleep;
 use std::time::Duration;
@@ -272,6 +277,38 @@ pub fn run_report_silent(info: &TraceInfo, report_cycles: usize) -> anyhow::Resu
     Ok(())
 }
 
+/// Run a trace and generate a dot file.
+pub fn run_report_dot(info: &TraceInfo, report_cycles: usize) -> anyhow::Result<()> {
+    struct DotWrapper<'a>(Dot<'a, &'a DiGraphMap<IpAddr, ()>>);
+    impl Debug for DotWrapper<'_> {
+        fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+            self.0.fmt(f)
+        }
+    }
+    wait_for_round(&info.data, report_cycles)?;
+    let trace = info.data.read().clone();
+    let mut graph: DiGraphMap<IpAddr, ()> = DiGraphMap::new();
+    for (flow, _id) in trace.flows() {
+        for (fst, snd) in flow.entries.windows(2).map(|pair| (pair[0], pair[1])) {
+            match (fst, snd) {
+                (FlowEntry::Known(addr1), FlowEntry::Known(addr2)) => {
+                    graph.add_edge(addr1, addr2, ());
+                }
+                (FlowEntry::Known(addr1), FlowEntry::Unknown) => {
+                    graph.add_edge(addr1, IpAddr::V4(Ipv4Addr::UNSPECIFIED), ());
+                }
+                (FlowEntry::Unknown, FlowEntry::Known(addr2)) => {
+                    graph.add_edge(IpAddr::V4(Ipv4Addr::UNSPECIFIED), addr2, ());
+                }
+                _ => {}
+            }
+        }
+    }
+    let dot = DotWrapper(Dot::with_config(&graph, &[Config::EdgeNoLabel]));
+    print!("{dot:?}");
+    Ok(())
+}
+
 /// Block until trace data for round `round` is available.
 fn wait_for_round(trace_data: &Arc<RwLock<Trace>>, report_cycles: usize) -> anyhow::Result<Trace> {
     let mut trace = trace_data.read().clone();

trippy-config-sample.toml

@@ -29,6 +29,7 @@
 #   markdown    - Generate a markdown text table report for N cycles
 #   csv         - Generate a CSV report for N cycles
 #   json        - Generate a JSON report for N cycles
+#   dot         - Generate a Graphviz DOT report for N cycles
 #   silent      - Do not generate any output for N cycles
 mode = "tui"