Fix permissions on Docker testing

This appears to be due to a CI change that resulted in different user
IDs between the host and the container image.

Signed-off-by: Alexander Scheel <alex.scheel@hashicorp.com>

.circleci/config/commands/go_test.yml

@@ -95,7 +95,9 @@ steps:
         # has its own remote docker VM.
 
         make prep
-        mkdir -p test-results/go-test
+
+        # Permissions have changed inside docker containers; see hack note below.
+        mkdir --mode=777 -p test-results/go-test
 
         # We don't want VAULT_LICENSE set when running Go tests, because that's
         # not what developers have in their environments and it could break some
@@ -116,6 +118,19 @@ steps:
           # reasons unclear.
           export DOCKER_API_VERSION=1.39
 
+          # Hack: Docker permissions appear to have changed; let's explicitly
+          # chmod the docker certificate path to give other grouped users
+          # access.
+          #
+          # Notably, in this shell pipeline we see:
+          # uid=1001(circleci) gid=1002(circleci) groups=1002(circleci)
+          #
+          # but inside the docker image below, we see:
+          # uid=3434(circleci) gid=3434(circleci) groups=3434(circleci)
+          #
+          # See also: https://github.com/CircleCI-Public/cimg-base/issues/122
+          chmod o+r -R $DOCKER_CERT_PATH
+
           TEST_DOCKER_NETWORK_NAME="${CIRCLE_WORKFLOW_JOB_ID}-${CIRCLE_NODE_INDEX}"
           export TEST_DOCKER_NETWORK_ID=$(docker network list --quiet --no-trunc --filter="name=${TEST_DOCKER_NETWORK_NAME}")
           if [ -z $TEST_DOCKER_NETWORK_ID ]; then