fix: make container UID/GID configurable for bind-mount compatibility

When using bind mounts, the host directory's UID/GID must match the
container user. Add PUID/PGID build args (default 1000) so users can
build with --build-arg PUID=$(id -u) --build-arg PGID=$(id -g) to
match their host user. Compose passes these from .env or shell vars.

https://claude.ai/code/session_0153nX7vQSjEFPpZTgZdDmu5

Author: claude

Dockerfile

@@ -46,7 +46,12 @@ FROM alpine:3.20
 RUN apk add --no-cache ca-certificates tzdata
 
 # Create non-root user for runtime security.
-RUN adduser -D -H -s /sbin/nologin chronicle
+# PUID/PGID let you match the host directory owner when using bind mounts.
+# Build with: docker build --build-arg PUID=$(id -u) --build-arg PGID=$(id -g) .
+ARG PUID=1000
+ARG PGID=1000
+RUN addgroup -g "$PGID" chronicle \
+    && adduser -D -H -s /sbin/nologin -G chronicle -u "$PUID" chronicle
 
 # Copy the compiled binary.
 COPY --from=builder /chronicle /usr/local/bin/chronicle

docker-compose.yml

@@ -19,6 +19,11 @@ services:
     build:
       context: .
       dockerfile: Dockerfile
+      args:
+        # Match container UID/GID to the host user that owns the bind-mount
+        # directory. Override in .env or shell: PUID=$(id -u) PGID=$(id -g)
+        PUID: ${PUID:-1000}
+        PGID: ${PGID:-1000}
     container_name: chronicle
     ports:
       - "8080:8080"