diff --git a/tests/docker/dockerfiles/alpine.docker b/tests/docker/dockerfiles/alpine.docker
index 7589f6c6ed..799932bcc9 100644
--- a/tests/docker/dockerfiles/alpine.docker
+++ b/tests/docker/dockerfiles/alpine.docker
@@ -124,3 +124,8 @@ ENV LANG "en_US.UTF-8"
 ENV MAKE "/usr/bin/make"
 ENV NINJA "/usr/bin/ninja"
 ENV PYTHON "/usr/bin/python3"
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/centos8.docker b/tests/docker/dockerfiles/centos8.docker
index bab67ccd41..d87a94b97b 100644
--- a/tests/docker/dockerfiles/centos8.docker
+++ b/tests/docker/dockerfiles/centos8.docker
@@ -138,3 +138,8 @@ ENV LANG "en_US.UTF-8"
 ENV MAKE "/usr/bin/make"
 ENV NINJA "/usr/bin/ninja"
 ENV PYTHON "/usr/bin/python3.8"
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-amd64-cross.docker b/tests/docker/dockerfiles/debian-amd64-cross.docker
index 856db95100..5d03b5c22d 100644
--- a/tests/docker/dockerfiles/debian-amd64-cross.docker
+++ b/tests/docker/dockerfiles/debian-amd64-cross.docker
@@ -169,3 +169,8 @@ ENV ABI "x86_64-linux-gnu"
 ENV MESON_OPTS "--cross-file=x86_64-linux-gnu"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=x86_64-linux-gnu-
 ENV DEF_TARGET_LIST x86_64-softmmu,x86_64-linux-user,i386-softmmu,i386-linux-user
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-amd64.docker b/tests/docker/dockerfiles/debian-amd64.docker
index e3dba71ad5..febc46e700 100644
--- a/tests/docker/dockerfiles/debian-amd64.docker
+++ b/tests/docker/dockerfiles/debian-amd64.docker
@@ -155,3 +155,8 @@ RUN git clone https://github.com/luigirizzo/netmap.git /usr/src/netmap
 RUN cd /usr/src/netmap && git checkout v11.3
 RUN cd /usr/src/netmap/LINUX && ./configure --no-drivers --no-apps --kernel-dir=$(ls -d /usr/src/linux-headers-*-amd64) && make install
 ENV QEMU_CONFIGURE_OPTS --enable-netmap
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-arm64-cross.docker b/tests/docker/dockerfiles/debian-arm64-cross.docker
index b00e9e9bcf..b9501a21bc 100644
--- a/tests/docker/dockerfiles/debian-arm64-cross.docker
+++ b/tests/docker/dockerfiles/debian-arm64-cross.docker
@@ -168,3 +168,8 @@ ENV ABI "aarch64-linux-gnu"
 ENV MESON_OPTS "--cross-file=aarch64-linux-gnu"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=aarch64-linux-gnu-
 ENV DEF_TARGET_LIST aarch64-softmmu,aarch64-linux-user
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-armel-cross.docker b/tests/docker/dockerfiles/debian-armel-cross.docker
index fb1129f256..f21742ede5 100644
--- a/tests/docker/dockerfiles/debian-armel-cross.docker
+++ b/tests/docker/dockerfiles/debian-armel-cross.docker
@@ -167,3 +167,8 @@ ENV ABI "arm-linux-gnueabi"
 ENV MESON_OPTS "--cross-file=arm-linux-gnueabi"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=arm-linux-gnueabi-
 ENV DEF_TARGET_LIST arm-softmmu,arm-linux-user,armeb-linux-user
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-armhf-cross.docker b/tests/docker/dockerfiles/debian-armhf-cross.docker
index 7a2b864a38..decdeda6f2 100644
--- a/tests/docker/dockerfiles/debian-armhf-cross.docker
+++ b/tests/docker/dockerfiles/debian-armhf-cross.docker
@@ -168,3 +168,8 @@ ENV ABI "arm-linux-gnueabihf"
 ENV MESON_OPTS "--cross-file=arm-linux-gnueabihf"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=arm-linux-gnueabihf-
 ENV DEF_TARGET_LIST arm-softmmu,arm-linux-user
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-mips64el-cross.docker b/tests/docker/dockerfiles/debian-mips64el-cross.docker
index 5a3340e964..1df05fcf20 100644
--- a/tests/docker/dockerfiles/debian-mips64el-cross.docker
+++ b/tests/docker/dockerfiles/debian-mips64el-cross.docker
@@ -165,3 +165,8 @@ ENV ABI "mips64el-linux-gnuabi64"
 ENV MESON_OPTS "--cross-file=mips64el-linux-gnuabi64"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=mips64el-linux-gnuabi64-
 ENV DEF_TARGET_LIST mips64el-softmmu,mips64el-linux-user
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-mipsel-cross.docker b/tests/docker/dockerfiles/debian-mipsel-cross.docker
index 422fdebe8f..019b8dcaff 100644
--- a/tests/docker/dockerfiles/debian-mipsel-cross.docker
+++ b/tests/docker/dockerfiles/debian-mipsel-cross.docker
@@ -165,3 +165,8 @@ ENV ABI "mipsel-linux-gnu"
 ENV MESON_OPTS "--cross-file=mipsel-linux-gnu"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=mipsel-linux-gnu-
 ENV DEF_TARGET_LIST mipsel-softmmu,mipsel-linux-user
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-ppc64el-cross.docker b/tests/docker/dockerfiles/debian-ppc64el-cross.docker
index 78d7ae6211..3ceab4c502 100644
--- a/tests/docker/dockerfiles/debian-ppc64el-cross.docker
+++ b/tests/docker/dockerfiles/debian-ppc64el-cross.docker
@@ -167,3 +167,8 @@ ENV ABI "powerpc64le-linux-gnu"
 ENV MESON_OPTS "--cross-file=powerpc64le-linux-gnu"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=powerpc64le-linux-gnu-
 ENV DEF_TARGET_LIST ppc64-softmmu,ppc64-linux-user
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/debian-s390x-cross.docker b/tests/docker/dockerfiles/debian-s390x-cross.docker
index d06ea3605a..6c216dde48 100644
--- a/tests/docker/dockerfiles/debian-s390x-cross.docker
+++ b/tests/docker/dockerfiles/debian-s390x-cross.docker
@@ -166,3 +166,8 @@ ENV ABI "s390x-linux-gnu"
 ENV MESON_OPTS "--cross-file=s390x-linux-gnu"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=s390x-linux-gnu-
 ENV DEF_TARGET_LIST s390x-softmmu,s390x-linux-user
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/fedora-win32-cross.docker b/tests/docker/dockerfiles/fedora-win32-cross.docker
index 5b66b0e256..63a0000936 100644
--- a/tests/docker/dockerfiles/fedora-win32-cross.docker
+++ b/tests/docker/dockerfiles/fedora-win32-cross.docker
@@ -101,3 +101,8 @@ ENV ABI "i686-w64-mingw32"
 ENV MESON_OPTS "--cross-file=/usr/share/mingw/toolchain-mingw32.meson"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=i686-w64-mingw32-
 ENV DEF_TARGET_LIST i386-softmmu
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/fedora-win64-cross.docker b/tests/docker/dockerfiles/fedora-win64-cross.docker
index b94fd63cca..531e539e85 100644
--- a/tests/docker/dockerfiles/fedora-win64-cross.docker
+++ b/tests/docker/dockerfiles/fedora-win64-cross.docker
@@ -101,3 +101,8 @@ ENV ABI "x86_64-w64-mingw32"
 ENV MESON_OPTS "--cross-file=/usr/share/mingw/toolchain-mingw64.meson"
 ENV QEMU_CONFIGURE_OPTS --cross-prefix=x86_64-w64-mingw32-
 ENV DEF_TARGET_LIST x86_64-softmmu
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/fedora.docker b/tests/docker/dockerfiles/fedora.docker
index 8e06d080b8..4dd1fce890 100644
--- a/tests/docker/dockerfiles/fedora.docker
+++ b/tests/docker/dockerfiles/fedora.docker
@@ -146,3 +146,8 @@ ENV LANG "en_US.UTF-8"
 ENV MAKE "/usr/bin/make"
 ENV NINJA "/usr/bin/ninja"
 ENV PYTHON "/usr/bin/python3"
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/opensuse-leap.docker b/tests/docker/dockerfiles/opensuse-leap.docker
index 9bf9b50dad..f39e8a4d44 100644
--- a/tests/docker/dockerfiles/opensuse-leap.docker
+++ b/tests/docker/dockerfiles/opensuse-leap.docker
@@ -135,3 +135,8 @@ ENV LANG "en_US.UTF-8"
 ENV MAKE "/usr/bin/make"
 ENV NINJA "/usr/bin/ninja"
 ENV PYTHON "/usr/bin/python3.9"
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/ubuntu2004.docker b/tests/docker/dockerfiles/ubuntu2004.docker
index 95d951953f..a6f7071351 100644
--- a/tests/docker/dockerfiles/ubuntu2004.docker
+++ b/tests/docker/dockerfiles/ubuntu2004.docker
@@ -146,3 +146,8 @@ ENV LANG "en_US.UTF-8"
 ENV MAKE "/usr/bin/make"
 ENV NINJA "/usr/bin/ninja"
 ENV PYTHON "/usr/bin/python3"
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/docker/dockerfiles/ubuntu2204.docker b/tests/docker/dockerfiles/ubuntu2204.docker
index 30b9e56793..6fea090f02 100644
--- a/tests/docker/dockerfiles/ubuntu2204.docker
+++ b/tests/docker/dockerfiles/ubuntu2204.docker
@@ -145,3 +145,8 @@ ENV LANG "en_US.UTF-8"
 ENV MAKE "/usr/bin/make"
 ENV NINJA "/usr/bin/ninja"
 ENV PYTHON "/usr/bin/python3"
+# As a final step configure the user (if env is defined)
+ARG USER
+ARG UID
+RUN if [ "${USER}" ]; then \
+  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
diff --git a/tests/lcitool/refresh b/tests/lcitool/refresh
index cc9e34ac87..c0d7ad5516 100755
--- a/tests/lcitool/refresh
+++ b/tests/lcitool/refresh
@@ -53,6 +53,15 @@ def generate(filename, cmd, trailer):
         content += trailer
     atomic_write(filename, content)
 
+# Optional user setting, this will always be the last thing added
+# so maximise the number of layers that are cached
+add_user_mapping = [
+    "# As a final step configure the user (if env is defined)",
+    "ARG USER",
+    "ARG UID",
+    "RUN if [ \"${USER}\" ]; then \\",
+    "  id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi\n"
+]
 
 def generate_dockerfile(host, target, cross=None, trailer=None):
     filename = Path(src_dir, "tests", "docker", "dockerfiles", host + ".docker")
@@ -60,6 +69,12 @@ def generate_dockerfile(host, target, cross=None, trailer=None):
     if cross is not None:
         cmd.extend(["--cross", cross])
     cmd.extend([target, "qemu"])
+
+    if trailer is not None:
+        trailer += "\n".join(add_user_mapping)
+    else:
+        trailer = "\n".join(add_user_mapping)
+
     generate(filename, cmd, trailer)
 
 
