docker: add an entrypoint

running as an arbitrary user is now possible setting the following
env vars too:

SFTPGO_PUID
SFTPGO_PGID

Fixes #217

Dockerfile

@@ -23,11 +23,46 @@ RUN set -xe && \
     export COMMIT_SHA=${COMMIT_SHA:-$(git describe --always --dirty)} && \
     go build $(if [ -n "${FEATURES}" ]; then echo "-tags ${FEATURES}"; fi) -ldflags "-s -w -X github.com/drakkan/sftpgo/version.commit=${COMMIT_SHA} -X github.com/drakkan/sftpgo/version.date=`date -u +%FT%TZ`" -v -o sftpgo
 
-FROM debian:buster-slim
+# install gosu
+ENV GOSU_VERSION 1.12
+
+RUN set -eux; \
+# save list of currently installed packages for later so we can clean up
+	savedAptMark="$(apt-mark showmanual)"; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends ca-certificates wget; \
+	if ! command -v gpg; then \
+		apt-get install -y --no-install-recommends gnupg2 dirmngr; \
+	elif gpg --version | grep -q '^gpg (GnuPG) 1\.'; then \
+# "This package provides support for HKPS keyservers." (GnuPG 1.x only)
+		apt-get install -y --no-install-recommends gnupg-curl; \
+	fi; \
+	rm -rf /var/lib/apt/lists/*; \
+	\
+	dpkgArch="$(dpkg --print-architecture | awk -F- '{ print $NF }')"; \
+	wget -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$dpkgArch"; \
+	wget -O /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$dpkgArch.asc"; \
+	\
+# verify the signature
+	export GNUPGHOME="$(mktemp -d)"; \
+	gpg --batch --keyserver hkps://keys.openpgp.org --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4; \
+	gpg --batch --verify /usr/local/bin/gosu.asc /usr/local/bin/gosu; \
+	command -v gpgconf && gpgconf --kill all || :; \
+	rm -rf "$GNUPGHOME" /usr/local/bin/gosu.asc; \
+	\
+# clean up fetch dependencies
+	apt-mark auto '.*' > /dev/null; \
+	[ -z "$savedAptMark" ] || apt-mark manual $savedAptMark; \
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	\
+	chmod +x /usr/local/bin/gosu; \
+# verify that the binary works
+	gosu --version; \
+	gosu nobody true
 
-RUN apt-get update && apt-get install --no-install-recommends -y ca-certificates mime-support && apt-get clean
+FROM debian:buster-slim
 
-SHELL ["/bin/bash", "-c"]
+RUN apt-get update && apt-get install --no-install-recommends -y ca-certificates mime-support && rm -rf /var/lib/apt/lists/*
 
 RUN mkdir -p /etc/sftpgo /var/lib/sftpgo /usr/share/sftpgo /srv/sftpgo
 
@@ -37,12 +72,13 @@ RUN groupadd --system -g 1000 sftpgo && \
     --comment "SFTPGo user" --uid 1000 sftpgo
 
 # Install some optional packages used by SFTPGo features
-RUN apt-get update && apt-get install --no-install-recommends -y git rsync && apt-get clean
+RUN apt-get update && apt-get install --no-install-recommends -y git rsync && apt-get clean && rm -rf /var/lib/apt/lists/*
 
 COPY --from=builder /workspace/sftpgo.json /etc/sftpgo/sftpgo.json
 COPY --from=builder /workspace/templates /usr/share/sftpgo/templates
 COPY --from=builder /workspace/static /usr/share/sftpgo/static
 COPY --from=builder /workspace/sftpgo /usr/local/bin/
+COPY --from=builder /usr/local/bin/gosu /usr/local/bin/
 
 # Log to the stdout so the logs will be available using docker logs
 ENV SFTPGO_LOG_FILE_PATH=""
@@ -55,11 +91,14 @@ RUN sed -i "s|\"users_base_dir\": \"\",|\"users_base_dir\": \"/srv/sftpgo/data\"
     sed -i "s|\"backups\"|\"/srv/sftpgo/backups\"|" /etc/sftpgo/sftpgo.json && \
     sed -i "s|\"bind_address\": \"127.0.0.1\",|\"bind_address\": \"\",|" /etc/sftpgo/sftpgo.json
 
-RUN chown -R sftpgo:sftpgo /etc/sftpgo && chown sftpgo:sftpgo /var/lib/sftpgo /srv/sftpgo
+COPY ./docker/scripts/entrypoint.sh /docker-entrypoint.sh
+
+RUN chown -R sftpgo:sftpgo /etc/sftpgo && chown sftpgo:sftpgo /var/lib/sftpgo /srv/sftpgo && \
+    chmod 755 /docker-entrypoint.sh
 
 WORKDIR /var/lib/sftpgo
-USER 1000:1000
 
 VOLUME [ "/var/lib/sftpgo", "/srv/sftpgo" ]
 
-CMD sftpgo serve
+ENTRYPOINT ["/docker-entrypoint.sh"]
+CMD ["sftpgo", "serve"]

Dockerfile.alpine

@@ -28,9 +28,7 @@ RUN set -xe && \
 
 FROM alpine:3.12
 
-RUN apk add --update --no-cache ca-certificates tzdata bash mailcap
-
-SHELL ["/bin/bash", "-c"]
+RUN apk add --update --no-cache ca-certificates tzdata bash mailcap su-exec
 
 # set up nsswitch.conf for Go's "netgo" implementation
 # https://github.com/gliderlabs/docker-alpine/issues/367#issuecomment-424546457
@@ -39,7 +37,7 @@ RUN test ! -e /etc/nsswitch.conf && echo 'hosts: files dns' > /etc/nsswitch.conf
 RUN mkdir -p /etc/sftpgo /var/lib/sftpgo /usr/share/sftpgo /srv/sftpgo
 
 RUN addgroup -g 1000 -S sftpgo && \
-    adduser -u 1000 -h /var/lib/sftpgo -s /sbin/nologin -G sftpgo -S -D -H sftpgo
+    adduser -u 1000 -h /var/lib/sftpgo -s /sbin/nologin -G sftpgo -S -D -H -g "SFTPGo user" sftpgo
 
 # Install some optional packages used by SFTPGo features
 RUN apk add --update --no-cache rsync git
@@ -60,11 +58,14 @@ RUN sed -i "s|\"users_base_dir\": \"\",|\"users_base_dir\": \"/srv/sftpgo/data\"
     sed -i "s|\"backups\"|\"/srv/sftpgo/backups\"|" /etc/sftpgo/sftpgo.json && \
     sed -i "s|\"bind_address\": \"127.0.0.1\",|\"bind_address\": \"\",|" /etc/sftpgo/sftpgo.json
 
-RUN chown -R sftpgo:sftpgo /etc/sftpgo && chown sftpgo:sftpgo /var/lib/sftpgo /srv/sftpgo
+COPY ./docker/scripts/entrypoint-alpine.sh /docker-entrypoint.sh
+
+RUN chown -R sftpgo:sftpgo /etc/sftpgo && chown sftpgo:sftpgo /var/lib/sftpgo /srv/sftpgo && \
+    chmod 755 /docker-entrypoint.sh
 
 WORKDIR /var/lib/sftpgo
-USER 1000:1000
 
 VOLUME [ "/var/lib/sftpgo", "/srv/sftpgo" ]
 
-CMD sftpgo serve
+ENTRYPOINT ["/docker-entrypoint.sh"]
+CMD ["sftpgo", "serve"]

docker/README.md

@@ -98,6 +98,11 @@ docker run --name some-sftpgo \
     -d "drakkan/sftpgo:tag"
 ```
 
+Alternately you can set the following environment variables:
+
+- `SFTPGO_PUID`, sets the numeric user ID to use
+- `SFTPGO_PGID`, sets the numeric group ID to use
+
 ## Image Variants
 
 The `sftpgo` images comes in many flavors, each designed for a specific use case. The `edge` and `edge-alpine`tags are updated after each new commit.

docker/scripts/entrypoint-alpine.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+SFTPGO_PUID=${SFTPGO_PUID:-1000}
+SFTPGO_PGID=${SFTPGO_PGID:-1000}
+
+if [ "$1" = 'sftpgo' ]; then
+    if [ "$(id -u)" = '0' ]; then
+        for DIR in "/etc/sftpgo" "/var/lib/sftpgo" "/srv/sftpgo"
+        do
+            DIR_UID=$(stat -c %u ${DIR})
+            DIR_GID=$(stat -c %g ${DIR})
+            if [ ${DIR_UID} != ${SFTPGO_PUID} ] || [ ${DIR_GID} != ${SFTPGO_PGID} ]; then
+                echo `date +%Y-%m-%dT%H:%M:%S` - "entrypoint, change owner for ${DIR} uid: ${SFTPGO_PUID} gid: ${SFTPGO_PGID}"
+                if [ ${DIR} = "/etc/sftpgo" ]; then
+                    chown -R ${SFTPGO_PUID}:${SFTPGO_PGID} ${DIR}
+                else
+                    chown ${SFTPGO_PUID}:${SFTPGO_PGID} ${DIR}
+                fi
+            fi
+        done
+        echo `date +%Y-%m-%dT%H:%M:%S` - "entrypoint, run as uid: ${SFTPGO_PUID} gid: ${SFTPGO_PGID}"
+        exec su-exec ${SFTPGO_PUID}:${SFTPGO_PGID} "$@"
+    fi
+
+    exec "$@"
+fi
+
+exec "$@"

docker/scripts/entrypoint.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+
+SFTPGO_PUID=${SFTPGO_PUID:-1000}
+SFTPGO_PGID=${SFTPGO_PGID:-1000}
+
+if [ "$1" = 'sftpgo' ]; then
+    if [ "$(id -u)" = '0' ]; then
+        getent passwd ${SFTPGO_PUID} > /dev/null
+	    HAS_PUID=$?
+	    getent group ${SFTPGO_PGID} > /dev/null
+	    HAS_PGID=$?
+        if [ ${HAS_PUID} -ne 0 ] || [ ${HAS_PGID} -ne 0 ]; then
+            echo `date +%Y-%m-%dT%H:%M:%S.%3N` - "entrypoint, prepare to run as uid: ${SFTPGO_PUID} gid: ${SFTPGO_PGID}"
+            if [ ${HAS_PGID} -ne 0 ];  then
+                echo `date +%Y-%m-%dT%H:%M:%S.%3N` - "entrypoint, set GID to: ${SFTPGO_PGID}"
+                groupmod -g ${SFTPGO_PGID} sftpgo
+            fi
+            if [ ${HAS_PUID} -ne 0 ]; then
+                echo `date +%Y-%m-%dT%H:%M:%S.%3N` - "entrypoint, set UID to: ${SFTPGO_PUID}"
+                usermod -u ${SFTPGO_PUID} sftpgo
+            fi
+            chown -R ${SFTPGO_PUID}:${SFTPGO_PGID} /etc/sftpgo
+            chown ${SFTPGO_PUID}:${SFTPGO_PGID} /var/lib/sftpgo /srv/sftpgo
+        fi
+        echo `date +%Y-%m-%dT%H:%M:%S.%3N` - "entrypoint, run as uid: ${SFTPGO_PUID} gid: ${SFTPGO_PGID}"
+        exec gosu ${SFTPGO_PUID}:${SFTPGO_PGID} "$@"
+    fi
+
+    exec "$@"
+fi
+
+exec "$@"