feat: Linux image, built by the shared workflow

.github/workflows/build.yaml

@@ -10,7 +10,11 @@ on:
 
 jobs:
   build:
-    uses: daemonless/dbuild/.github/workflows/daemonless-build.yaml@main
+    # Trial of dbuild#feat/linux-images: back to @main (and no dbuild_ref)
+    # once that is merged.
+    uses: daemonless/dbuild/.github/workflows/daemonless-build.yaml@feat/linux-images
     with:
       image_name: reverse-proxy
+      dbuild_ref: feat/linux-images
+      linux: true
     secrets: inherit

Containerfile.linux

@@ -0,0 +1,68 @@
+# reverse-proxy on Linux, built only by dbuild's shared GitHub workflow
+# (build-linux job): the same Caddy with the same DNS modules, the same
+# admin and UI, on Alpine with s6. Caddy runs as root to bind 80/443; the
+# admin runs as bsd (PUID/PGID), as on FreeBSD. Keep APP_VER with
+# Containerfile.j2's: the manifest adds this image to a tag only when the
+# versions agree.
+ARG APP_VER=0.2.0
+ARG CADDY_VERSION=
+
+FROM golang:1.26-alpine AS caddy-build
+ARG CADDY_VERSION
+RUN apk add --no-cache git ca-certificates curl && \
+    go install github.com/caddyserver/xcaddy/cmd/xcaddy@v0.4.7
+RUN v="${CADDY_VERSION:-$(curl -fsSI https://github.com/caddyserver/caddy/releases/latest | grep -io 'releases/tag/v[^[:space:]]*' | head -1 | cut -d/ -f3)}" && \
+    test -n "$v" && \
+    CGO_ENABLED=0 GOFLAGS=-buildvcs=false xcaddy build "$v" \
+      --with github.com/caddy-dns/cloudflare \
+      --with github.com/caddy-dns/route53 \
+      --with github.com/caddy-dns/desec \
+      --with github.com/caddy-dns/porkbun \
+      --with github.com/caddy-dns/hetzner \
+      --with github.com/caddy-dns/ovh \
+      --with github.com/caddy-dns/gandi \
+      --with github.com/caddy-dns/rfc2136 \
+      --with github.com/caddy-dns/acmedns \
+      --with github.com/caddy-dns/duckdns@v0.5.0 \
+      --output /out/caddy && \
+    /out/caddy version
+
+FROM node:24-alpine AS ui-build
+COPY admin/ui/package.json admin/ui/package-lock.json /src/ui/
+RUN cd /src/ui && npm ci --no-fund --no-audit
+COPY admin/ui/ /src/ui/
+RUN cd /src/ui && npm run build
+
+FROM golang:1.26-alpine AS admin-build
+ARG APP_VER
+COPY admin/ /src/
+COPY --from=ui-build /src/ui/dist/ /src/ui/dist/
+RUN cd /src && CGO_ENABLED=0 go build -trimpath \
+      -ldflags "-s -w -X main.version=${APP_VER}" \
+      -o /out/reverse-proxy ./cmd/reverse-proxy
+
+FROM alpine:3.24
+ARG APP_VER
+LABEL org.opencontainers.image.title="Daemonless Reverse Proxy" \
+      org.opencontainers.image.description="Friendly HTTPS names for the services on your network: a managed Caddy reverse proxy with a web UI, secure by default." \
+      org.opencontainers.image.source="https://github.com/daemonless/reverse-proxy" \
+      org.opencontainers.image.url="https://daemonless.io/images/reverse-proxy/" \
+      org.opencontainers.image.licenses="BSD-2-Clause" \
+      org.opencontainers.image.vendor="daemonless" \
+      org.opencontainers.image.authors="daemonless" \
+      io.daemonless.category="Network" \
+      io.daemonless.port="8443" \
+      io.daemonless.volumes="/config,/data"
+RUN apk add --no-cache s6 ca-certificates tzdata curl && \
+    addgroup -g 1000 bsd && adduser -D -H -u 1000 -G bsd -s /sbin/nologin bsd && \
+    mkdir -p /app /config /data && echo "${APP_VER}" > /app/version
+COPY --from=caddy-build /out/caddy /usr/local/bin/caddy
+COPY --from=admin-build /out/reverse-proxy /usr/local/bin/reverse-proxy
+COPY --from=ui-build /src/ui/dist/ /usr/local/share/reverse-proxy/ui/
+COPY root/etc/reverse-proxy/bootstrap.json /etc/reverse-proxy/bootstrap.json
+COPY root-linux/ /
+RUN chmod +x /init /healthz /usr/local/bin/s6-ready-when /etc/cont-init.d/* /etc/services.d/*/run
+EXPOSE 80 443 8443
+VOLUME ["/config", "/data"]
+HEALTHCHECK --interval=30s --timeout=10s CMD /healthz
+ENTRYPOINT ["/init"]

root-linux/etc/cont-init.d/10-users

@@ -0,0 +1,7 @@
+#!/bin/sh
+# PUID/PGID mapping for the admin, as the FreeBSD image does.
+PUID="${PUID:-1000}"; PGID="${PGID:-1000}"
+if [ "$(id -g bsd)" != "$PGID" ]; then delgroup bsd 2>/dev/null || true; addgroup -g "$PGID" bsd; fi
+if [ "$(id -u bsd)" != "$PUID" ]; then deluser bsd 2>/dev/null || true; adduser -D -H -u "$PUID" -G bsd -s /sbin/nologin bsd; fi
+echo "[usermod] User bsd configured (uid=$(id -u bsd), gid=$(id -g bsd))"
+mkdir -p /config/logs && chown -R bsd:bsd /config

root-linux/etc/cont-init.d/20-reverse-proxy-dirs

@@ -0,0 +1,17 @@
+#!/bin/sh
+# Socket directory: root-owned, group bsd. setgid so the sockets Caddy (root)
+# makes get the group bsd: FreeBSD does that by default, Linux needs the bit.
+# Nothing else runs here, so a socket left from an unclean stop is stale.
+rm -rf /var/run/reverse-proxy
+mkdir -p /var/run/reverse-proxy
+chown root:bsd /var/run/reverse-proxy
+chmod 2770 /var/run/reverse-proxy
+
+mkdir -p /config/secrets
+chown bsd:bsd /config/secrets
+chmod 0700 /config/secrets
+
+# Caddy (root) owns /data: certificates, ACME account, CA intermediate.
+mkdir -p /data
+chown root:root /data
+chmod 0700 /data

root-linux/etc/services.d/admin/notification-fd

@@ -0,0 +1 @@
+3

root-linux/etc/services.d/admin/run

@@ -0,0 +1,10 @@
+#!/bin/sh
+# The admin: UI, API, config renderer. Runs as bsd (PUID/PGID) and drives
+# Caddy over the unix sockets in /var/run/reverse-proxy.
+export HOME=/config
+s6-ready-when /healthz
+exec s6-setuidgid bsd /usr/local/bin/reverse-proxy \
+    -state /config \
+    -caddy-socket /var/run/reverse-proxy/caddy.sock \
+    -listen /var/run/reverse-proxy/admin.sock \
+    -probe-socket /var/run/reverse-proxy/tls.sock 2>&1

root-linux/etc/services.d/caddy/notification-fd

@@ -0,0 +1 @@
+3

root-linux/etc/services.d/caddy/run

@@ -0,0 +1,9 @@
+#!/bin/sh
+export XDG_DATA_HOME=/data
+export XDG_CONFIG_HOME=/data
+SOCK=/var/run/reverse-proxy/caddy.sock
+# Linux gives a new unix socket the creator's group, not the directory's
+# (FreeBSD does the latter), so hand it to bsd once Caddy has made it.
+( i=0; while [ ! -S "$SOCK" ] && [ $i -lt 300 ]; do sleep 0.2; i=$((i+1)); done; chgrp bsd "$SOCK" 2>/dev/null ) &
+s6-ready-when test -S "$SOCK"
+exec /usr/local/bin/caddy run --config /etc/reverse-proxy/bootstrap.json 2>&1

root-linux/healthz

@@ -0,0 +1,5 @@
+#!/bin/sh
+# As on FreeBSD: the admin answers on its socket, and answers 503 while Caddy
+# is not running. Asked directly, not through Caddy on :8443: a check before
+# the admin listened made Caddy log "admin.sock: no such file" at every boot.
+curl -sf -m 5 -o /dev/null --unix-socket /var/run/reverse-proxy/admin.sock http://admin/healthz

root-linux/init

@@ -0,0 +1,10 @@
+#!/bin/sh
+# Minimal init: run the one-shot cont-init scripts, then supervise the two
+# services with s6 (same layout as the FreeBSD image).
+set -e
+for f in /etc/cont-init.d/*; do
+    echo "[init] Running: $f"
+    "$f"
+done
+echo "[init] Initialization complete"
+exec s6-svscan /etc/services.d

root-linux/usr/local/bin/s6-ready-when

@@ -0,0 +1,17 @@
+#!/bin/sh
+# Poll a command until it succeeds, then signal s6 readiness on fd 3
+# (needs notification-fd = 3 in the service directory). Bounded, and dies
+# with its service.
+[ -n "$1" ] || { echo "Usage: s6-ready-when <command>"; exit 1; }
+CHECK_CMD="$*"
+SERVICE_PID=$PPID
+(
+    tries="${S6_READY_TIMEOUT:-300}"
+    while ! eval "$CHECK_CMD" >/dev/null 2>&1; do
+        kill -0 "$SERVICE_PID" 2>/dev/null || exit 0
+        tries=$((tries - 1)); [ "$tries" -gt 0 ] || exit 0
+        sleep 1
+    done
+    kill -0 "$SERVICE_PID" 2>/dev/null || exit 0
+    printf "\n" >&3
+) &