feat: pcap capturing and manipulation

.github/dependabot.yaml

@@ -11,7 +11,8 @@ updates:
   - package-ecosystem: "gomod"
     directory: "/" # Location of package manifests
     schedule:
-      interval: "daily"
+      interval: "weekly"
       time: "15:00"
+      day: "monday"
       timezone: "Australia/Sydney"
     labels: ["scope: deps", "priority: medium"]

.github/workflows/ci.yaml

@@ -15,11 +15,8 @@ permissions:
 
 jobs:
   lint:
-    strategy:
-      matrix:
-        os: [ubuntu-latest]
     name: golangci-lint
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
       - name: Install Go
@@ -40,52 +37,36 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v7
       - name: Install Go
-        id: setup-go
         uses: actions/setup-go@v7
         with:
           go-version-file: "go.mod"
-      - name: Download Go modules
-        shell: bash
-        if: ${{ steps.setup-go.outputs.cache-hit != 'true' }}
-        run: go mod download
       - name: go build
-        run: go build
+        run: go build ./...
       - name: go test
-        run: go test -v ./... -race
+        run: go test ./... -race
 
   container:
     name: container-build
+    if: github.ref == 'refs/heads/main'
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@v7
 
       - name: Install Go
-        id: setup-go
         uses: actions/setup-go@v7
         with:
           go-version-file: "go.mod"
 
-      - name: Download Go modules
-        shell: bash
-        if: ${{ steps.setup-go.outputs.cache-hit != 'true' }}
-        run: go mod download
-
       - name: Install ko
         run: go install github.com/google/ko@v0.18.1
 
       - name: Set build metadata
         id: meta
         shell: bash
-        env:
-          PR_NUMBER: ${{ github.event.pull_request.number }}
         run: |
           short_sha="${GITHUB_SHA::7}"
-          if [[ "${GITHUB_EVENT_NAME}" == "pull_request" && -n "${PR_NUMBER}" ]]; then
-            version="pr-${PR_NUMBER}-${short_sha}"
-          else
-            version="${GITHUB_REF_NAME}-${short_sha}"
-          fi
+          version="${GITHUB_REF_NAME}-${short_sha}"
           echo "version=${version}" >> "$GITHUB_OUTPUT"
           echo "build_date=$(date -u +'%Y-%m-%dT%H:%M:%SZ')" >> "$GITHUB_OUTPUT"
 

.github/workflows/release.yaml

@@ -22,14 +22,9 @@ jobs:
       with:
         fetch-depth: 0
     - name: Install Go
-      id: setup-go
       uses: actions/setup-go@v7
       with:
         go-version-file: "go.mod"
-    - name: Download Go modules
-      shell: bash
-      if: ${{ steps.setup-go.outputs.cache-hit != 'true' }}
-      run: go mod download
     - name: Install ko
       run: go install github.com/google/ko@v0.18.1
     - name: Log in to GHCR

.goreleaser.yaml

@@ -98,20 +98,4 @@ release:
 
         - [Documentation](https://gonetsim.lachlanharris.au/)
         - [Report Issues](https://github.com/{{ .Env.GITHUB_REPOSITORY }}/issues)
-        - [Discussions](https://github.com/{{ .Env.GITHUB_REPOSITORY }}/discussions)
-
-kos:
-  - id: gonetsim
-    build: gonetsim
-    repositories:
-      - ghcr.io/{{ .Env.GITHUB_REPOSITORY_OWNER }}/gonetsim
-    tags:
-      - "{{ .Version }}"
-      - "{{ .Major }}.{{ .Minor }}"
-      - latest
-    bare: true
-    platforms:
-      - linux/amd64
-      - linux/arm64
-    base_image: gcr.io/distroless/base-debian12
-    user: "0:0"
+        - [Discussions](https://github.com/{{ .Env.GITHUB_REPOSITORY }}/discussions)

.ko.yaml

@@ -17,4 +17,4 @@ builds:
       - -w
       - -X github.com/lachlanharrisdev/gonetsim/cmd.Version={{.Env.VERSION}}
       - -X github.com/lachlanharrisdev/gonetsim/cmd.Revision={{.Env.REVISION}}
-      - -X github.com/lachlanharrisdev/gonetsim/cmd.BuildDate={{.Env.BUILD_DATE}}
+      - -X github.com/lachlanharrisdev/gonetsim/cmd.Date={{.Env.BUILD_DATE}}

README.md

@@ -98,6 +98,7 @@ name = "irc"
 type = "tcp"
 listen = ":6667"
 handler = "lua:handlers/irc.lua" 
+capture = true
 ```
 
 Run it with `gonetsim run irc`, or skip using a pre-defined config entirely with `gonetsim run lua:handlers/irc.lua@:6667`.
@@ -106,6 +107,20 @@ The [`examples/`](examples/) directory has a full sample config plus example IRC
 
 <br/>
 
+## Captures
+
+Every run saves everything it handles to a single pcapng file, typically `~/.local/share/gonetsim/runs/<run-id>.pcapng`. GoNetSim prints the path on startup and a packet count on shutdown. Lua handlers can annotate interesting packets with `capture:comment("...")`, which shows up as a packet comment in Wireshark.
+
+```sh
+gonetsim run http --output ./case.pcapng   # choose the capture location
+gonetsim pcap ./case.pcapng                # summarize a capture
+gonetsim check                             # also verifies captures can be written
+```
+
+Two things to know when reading captures: handshakes are synthesized (sequence numbers start at 0, Ethernet MACs are fake, timestamps mark when GoNetSim wrote the frame), and TLS services capture ciphertext, not plaintext.
+
+<br/>
+
 ## Docker
 
 A lightweight distroless container setup lives in `docker/` and is built/published with `ko`. This is the recommended installation method if you require long periods of uptime, or if your system is incompatible with the provided binaries.