diff --git a/docker/Dockerfile.j2 b/docker/Dockerfile.j2
index 41e2f4f7..4a604085 100644
--- a/docker/Dockerfile.j2
+++ b/docker/Dockerfile.j2
@@ -37,10 +37,14 @@ RUN apk add --no-cache --upgrade \
     curl \
     tar
 {% else %}
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -80,6 +84,12 @@ ARG DB=mysql
 ARG DB=postgresql
 {% endif %}
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/aarch64/mysql/Dockerfile b/docker/aarch64/mysql/Dockerfile
index 4faea593..5dfac4a5 100644
--- a/docker/aarch64/mysql/Dockerfile
+++ b/docker/aarch64/mysql/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set mysql backend
 ARG DB=mysql
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/aarch64/sqlite/Dockerfile b/docker/aarch64/sqlite/Dockerfile
index 5eb00a3f..fa7cd7d6 100644
--- a/docker/aarch64/sqlite/Dockerfile
+++ b/docker/aarch64/sqlite/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set sqlite as default for DB ARG for backward compatibility
 ARG DB=sqlite
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/amd64/mysql/Dockerfile b/docker/amd64/mysql/Dockerfile
index 53da03a5..d2d304ff 100644
--- a/docker/amd64/mysql/Dockerfile
+++ b/docker/amd64/mysql/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set mysql backend
 ARG DB=mysql
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/amd64/mysql/Dockerfile.alpine b/docker/amd64/mysql/Dockerfile.alpine
index 56151652..b20754b2 100644
--- a/docker/amd64/mysql/Dockerfile.alpine
+++ b/docker/amd64/mysql/Dockerfile.alpine
@@ -27,6 +27,12 @@ FROM clux/muslrust:nightly-2019-12-19 as build
 # set mysql backend
 ARG DB=mysql
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/amd64/postgresql/Dockerfile b/docker/amd64/postgresql/Dockerfile
index decc2c28..532f6fdf 100644
--- a/docker/amd64/postgresql/Dockerfile
+++ b/docker/amd64/postgresql/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set postgresql backend
 ARG DB=postgresql
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/amd64/postgresql/Dockerfile.alpine b/docker/amd64/postgresql/Dockerfile.alpine
index 903a1a30..cef25d1c 100644
--- a/docker/amd64/postgresql/Dockerfile.alpine
+++ b/docker/amd64/postgresql/Dockerfile.alpine
@@ -27,6 +27,12 @@ FROM clux/muslrust:nightly-2019-12-19 as build
 # set postgresql backend
 ARG DB=postgresql
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/amd64/sqlite/Dockerfile b/docker/amd64/sqlite/Dockerfile
index d874f107..ec5b8496 100644
--- a/docker/amd64/sqlite/Dockerfile
+++ b/docker/amd64/sqlite/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set sqlite as default for DB ARG for backward compatibility
 ARG DB=sqlite
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/amd64/sqlite/Dockerfile.alpine b/docker/amd64/sqlite/Dockerfile.alpine
index 221e7e9e..1b08bd21 100644
--- a/docker/amd64/sqlite/Dockerfile.alpine
+++ b/docker/amd64/sqlite/Dockerfile.alpine
@@ -27,6 +27,12 @@ FROM clux/muslrust:nightly-2019-12-19 as build
 # set sqlite as default for DB ARG for backward compatibility
 ARG DB=sqlite
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/armv6/mysql/Dockerfile b/docker/armv6/mysql/Dockerfile
index 7bf2791a..11426179 100644
--- a/docker/armv6/mysql/Dockerfile
+++ b/docker/armv6/mysql/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set mysql backend
 ARG DB=mysql
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/armv6/sqlite/Dockerfile b/docker/armv6/sqlite/Dockerfile
index a9fe22b5..6c713221 100644
--- a/docker/armv6/sqlite/Dockerfile
+++ b/docker/armv6/sqlite/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set sqlite as default for DB ARG for backward compatibility
 ARG DB=sqlite
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/armv7/mysql/Dockerfile b/docker/armv7/mysql/Dockerfile
index 7fca4b57..5b8dc6c1 100644
--- a/docker/armv7/mysql/Dockerfile
+++ b/docker/armv7/mysql/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set mysql backend
 ARG DB=mysql
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal
 
diff --git a/docker/armv7/sqlite/Dockerfile b/docker/armv7/sqlite/Dockerfile
index 3e25b6e7..15ec9a2b 100644
--- a/docker/armv7/sqlite/Dockerfile
+++ b/docker/armv7/sqlite/Dockerfile
@@ -8,10 +8,14 @@ ENV VAULT_VERSION "v2.12.0b"
 
 ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
 
-ENV DEBIAN_FRONTEND=noninteractive \
-    LANG=C.UTF-8 \
-    TZ=UTC \
-    TERM=xterm-256color
+
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
+RUN echo $TERM
 
 RUN apt update -y \
     && apt install -y \
@@ -34,6 +38,12 @@ FROM rust:1.40 as build
 # set sqlite as default for DB ARG for backward compatibility
 ARG DB=sqlite
 
+# Build time options to avoid dpkg warnings and help with reproducible builds.
+ARG DEBIAN_FRONTEND=noninteractive
+ARG LANG=C.UTF-8
+ARG TZ=UTC
+ARG TERM=xterm-256color
+
 # Don't download rust docs
 RUN rustup set profile minimal