docker: Start kmd in the background. (#5514)

Dockerfile

@@ -53,8 +53,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates
     useradd --uid=999 --no-log-init --create-home --system --gid algorand algorand && \
     chown -R algorand:algorand /algod
 
-USER algorand
-
 COPY --chown=algorand:algorand --from=builder "/dist/bin/" "/node/bin/"
 COPY --chown=algorand:algorand --from=builder "/dist/files/run/" "/node/run/"
 

docker/files/run/run.sh

@@ -12,7 +12,7 @@ fi
 # as the algorand user.
 if [ "$(id -u)" = '0' ]; then
   chown -R algorand:algorand $ALGORAND_DATA
-  exec runuser -u algorand "$BASH_SOURCE"
+  runuser -u algorand "$BASH_SOURCE"
 fi
 
 # Script to configure or resume a network. Based on environment settings the
@@ -155,7 +155,7 @@ function start_new_public_network() {
 
 function start_private_network() {
   configure_data_dir
-  start_kmd
+  start_kmd &
 
   # TODO: Is there a way to properly exec a private network?
   goal network start -r "${ALGORAND_DATA}/.."