sync changes from paritytech/polkadot#3828

Dockerfile

@@ -8,7 +8,7 @@
 #
 # See the `deployments/README.md` for all the available `PROJECT` values.
 
-FROM paritytech/bridges-ci:latest as builder
+FROM docker.io/paritytech/bridges-ci:latest as builder
 WORKDIR /parity-bridges-common
 
 COPY . .
@@ -19,7 +19,7 @@ RUN cargo build --release --verbose -p ${PROJECT} && \
 
 # In this final stage we copy over the final binary and do some checks
 # to make sure that everything looks good.
-FROM ubuntu:20.04 as runtime
+FROM docker.io/library/ubuntu:20.04 as runtime
 
 # show backtraces
 ENV RUST_BACKTRACE 1

ci.Dockerfile

@@ -1,7 +1,7 @@
 # This file is a "runtime" part from a builder-pattern in Dockerfile, it's used in CI.
 # The only different part is that the compilation happens externally,
 # so COPY has a different source.
-FROM ubuntu:20.04
+FROM docker.io/library/ubuntu:20.04
 
 # show backtraces
 ENV RUST_BACKTRACE 1

deployments/BridgeDeps.Dockerfile

@@ -2,7 +2,7 @@
 #
 # This image is meant to be used as a building block when building images for
 # the various components in the bridge repo, such as nodes and relayers.
-FROM ubuntu:20.04
+FROM docker.io/library/ubuntu:20.04
 
 ENV LAST_DEPS_UPDATE 2021-04-01
 ENV DEBIAN_FRONTEND=noninteractive

deployments/monitoring/GrafanaMatrix.Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:alpine
+FROM docker.io/library/ruby:alpine
 
 RUN apk add --no-cache git