Initial commit: HTTP only, with Justfile for setup

.gitignore

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+# Vim swapfiles
+.*.swp
+
+# Generated files from pf-dev itself
+pf.conf
+.load

anchors/http

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+# vim: set ft=pf :
+# Handle loopback HTTP and HTTPS requests (ports 80 and 443) on non-privileged ports 8080 and 8443.
+rdr pass inet  proto tcp from any to 127.0.0.1 port  80 -> 127.0.0.1 port 8080
+rdr pass inet  proto tcp from any to 127.0.0.1 port 443 -> 127.0.0.1 port 8443
+rdr pass inet6 proto tcp from any to       ::1 port  80 ->       ::1 port 8080
+rdr pass inet6 proto tcp from any to       ::1 port 443 ->       ::1 port 8443

justfile

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+set positional-arguments := true
+
+# Top-level PF anchor names are allowed to be anything, but reverse domain
+# names seem to be preferred (MacOS uses com.apple by default), so I've
+# followed that convention with my own domain.
+
+anchor-name := "me.00dani.pf-dev"
+anchor-pattern := replace(anchor-name, ".", "\\.")
+
+# Display some basic info on how to use this project.
+help:
+    #!/bin/sh
+    echo "Enter \`just load\` with the anchors you want to enable! Supported anchors are:"
+    cd anchors
+    for ANCHOR in *; do
+        printf "%5s  %s\n" "$ANCHOR" "$(sed -n '2{s/^# //p;q;}' "$ANCHOR")"
+    done
+    grep -q '{{ anchor-pattern }}' /etc/pf.conf || {
+        printf "\n%s\n" "You will also need to run \`just install\` (uses sudo) for initial setup."
+    }
+
+# Generate a parent anchor file that loads the child anchors of your choice. Example: just load dns http
+load +ANCHORS:
+    #!/bin/sh
+    printf '%s\n%s\n' '# vim: set ft=pf :' '# This file was autogenerated! Call `just load` to create a fresh one.' > .load
+    for ANCHOR; do
+        [ -f "anchors/$ANCHOR" ] || {
+            echo "Unknown anchor $ANCHOR!" >&2
+            exit 1
+        }
+        printf '\nrdr-anchor "%s"\nload anchor "%s" from "%s/anchors/%s"\n' "$ANCHOR" "$ANCHOR" "$PWD" "$ANCHOR" >> .load
+    done
+
+# Globally install a modified pf.conf with pf-dev hooks added (will use sudo).
+install: _generate-pf-conf _display-pf-conf _install-pf-conf
+
+_generate-pf-conf:
+    sed -En '/"{{ anchor-pattern }}"/d; p; /^([a-z]+-)?anchor "com\.apple/ s/".+"/"{{ anchor-name }}"/ p' /etc/pf.conf > pf.conf
+    echo 'load anchor "{{ anchor-name }}" from "{{ justfile_directory() }}/.load"' >> pf.conf
+
+[no-exit-message]
+_display-pf-conf:
+    #!/bin/sh
+    echo "Generated a new pf.conf with pf-dev hooks included."
+    diff -u --color=auto /etc/pf.conf pf.conf
+    err=$?
+    if [ $err -eq 0 ]; then
+        echo "No changes need to be made to your pf.conf."
+        rm pf.conf
+        exit 1 # skip attempting to install
+    fi
+    if [ $err -gt 1 ]; then
+        echo "Failed to diff the generated pf.conf against your current pf.conf."
+        exit $err
+    fi
+
+[confirm("Are you happy to globally install the above pf.conf on your system?")]
+_install-pf-conf:
+    sudo cp pf.conf /etc/pf.conf
+    rm pf.conf