build: Remove the DOCKER_TRACE environment variable (#5583)

Our build scripts hide docker's output by default and only pass through
output when DOCKER_TRACE is set. Practically everyone else tends to use
DOCKER_TRACE=1 persistently. And, recently, GitHub Actions stopped
working with `/dev/stderr`

This change removes the DOCKER_TRACE environment variable so that output
is always emitted as it would when invoking docker directly.

BUILD.md

@@ -121,7 +121,7 @@ Started](https://linkerd.io/2/getting-started/)
 bin/k3d cluster create
 
 # build all docker images
-DOCKER_TRACE=1 bin/docker-build
+bin/docker-build
 
 # load all the images into k3d
 bin/image-load --k3d
@@ -431,7 +431,7 @@ The `bin/docker-build-proxy` script builds the proxy by pulling a pre-published
 proxy binary:
 
 ```bash
-DOCKER_TRACE=1 bin/docker-build-proxy
+bin/docker-build-proxy
 ```
 
 ### Multi-architecture builds

TEST.md

@@ -167,7 +167,7 @@ You can also test a locally-built version of the `linkerd` CLI.
 First build all of the Linkerd images by running:
 
 ```bash
-DOCKER_TRACE=1 bin/docker-build
+bin/docker-build
 ```
 
 That command also copies the corresponding `linkerd` binaries into the

bin/_docker.sh

@@ -11,9 +11,6 @@ bindir=$( cd "${BASH_SOURCE[0]%/*}" && pwd )
 # docker registry in, for instance, CI.
 export DOCKER_REGISTRY=${DOCKER_REGISTRY:-ghcr.io/linkerd}
 
-# When set, causes docker's build output to be emitted to stderr.
-export DOCKER_TRACE=${DOCKER_TRACE:-}
-
 # When set, use `docker buildx` and use the github actions cache to store/retrieve images
 export DOCKER_BUILDKIT=${DOCKER_BUILDKIT:-}
 
@@ -50,11 +47,6 @@ docker_build() {
     file=$1
     shift
 
-    output=/dev/null
-    if [ -n "$DOCKER_TRACE" ]; then
-        output=/dev/stderr
-    fi
-
     rootdir=$( cd "$bindir"/.. && pwd )
 
     if [ -n "$DOCKER_BUILDKIT" ]; then
@@ -82,15 +74,13 @@ docker_build() {
           $output_params \
           -t "$repo:$tag" \
           -f "$file" \
-          "$@" \
+          "$@"
-          > "$output"
     else
       log_debug "  :; docker build $rootdir -t $repo:$tag -f $file $*"
       docker build "$rootdir" \
           -t "$repo:$tag" \
           -f "$file" \
-          "$@" \
+          "$@"
-          > "$output"
     fi
 
     echo "$repo:$tag"

bin/docker-test-proxy

@@ -2,21 +2,13 @@
 
 set -eu
 
-# When set, causes docker's build output to be emitted to stderr.
-export DOCKER_TRACE=${DOCKER_TRACE:-}
 export RUST_LOG=${RUST_LOG:-}
 
 bindir=$( cd "${BASH_SOURCE[0]%/*}" && pwd )
 rootdir=$( cd "$bindir"/.. && pwd )
 
-if [ -n "$DOCKER_TRACE" ]; then
-	output=/dev/stderr
-else
-	output=/dev/null
-fi
-
 docker build -f "$rootdir/proxy/Dockerfile" . \
     --target build \
     -t proxy-build \
-    --build-arg=PROXY_UNOPTIMIZED=1 > $output
+    --build-arg=PROXY_UNOPTIMIZED=1
 docker run --rm -it proxy-build env RUST_LOG="$RUST_LOG" cargo test "$@"