Fix Docker build layout.

sts-agent/Dockerfile

@@ -1,4 +1,25 @@
+FROM ubuntu:18.04 AS grte
+
+ARG DEBIAN_FRONTEND=noninteractive
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends build-essential gawk bison python3 git texinfo ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+# GRTE v5 source, Google's glibc 2.27
+RUN git clone --depth 1 https://third-party-mirror.googlesource.com/GRTEv5 /src
+
+# Build the libraries into the library directory searched by the GRTE v5 loader
+WORKDIR /build
+RUN printf 'slibdir=/usr/grte/v5/lib64\nrtlddir=/usr/grte/v5/lib64\n' > configparms \
+    && /src/google3/third_party/grte/v5_src/glibc-2.27/configure \
+        --prefix=/usr/grte/v5 \
+        --libdir=/usr/grte/v5/lib64 \
+        --disable-werror \
+        --enable-kernel=3.2 \
+    && make -j"$(nproc)" \
+    && make install DESTDIR=/out
+
 FROM gcr.io/cloud-ingest/tsop-agent:latest
 
-# GRTE v5 shared libraries built by build-grte.sh, matching the GRTE v5 glibc the launcher is statically linked with.
-COPY grte/usr/grte/v5/lib64/ /usr/grte/v5/lib64/
+# GRTE v5 shared libraries matching the GRTE v5 glibc the launcher is statically linked with.
+COPY --from=grte /out/usr/grte/v5/lib64/ /usr/grte/v5/lib64/

sts-agent/build-grte.sh

@@ -1,30 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-
-prefix=/usr/grte/v5
-libdir="${prefix}/lib64"
-
-# Install the build tools
-export DEBIAN_FRONTEND=noninteractive
-apt-get update -qq
-apt-get install -y -qq --no-install-recommends build-essential gawk bison python3 git texinfo ca-certificates > /dev/null
-
-# Get the GRTE v5 source, Google's glibc 2.27
-git clone --depth 1 https://third-party-mirror.googlesource.com/GRTEv5 /src
-
-# Build the libraries in the library directory searched by the GRTE v5 loader
-mkdir /build
-cd /build
-cat > configparms <<EOF
-slibdir=${libdir}
-rtlddir=${libdir}
-EOF
-/src/google3/third_party/grte/v5_src/glibc-2.27/configure \
-    --prefix="${prefix}" \
-    --libdir="${libdir}" \
-    --disable-werror \
-    --enable-kernel=3.2
-make -j"$(nproc)"
-make install DESTDIR=/out
-
-ls -l "/out${libdir}/libc.so.6" "/out${libdir}/libm.so.6" "/out${libdir}/libpthread.so.0" "/out${libdir}/ld-linux-x86-64.so.2"