Switch logstash-basics to stop assuming the logstash image includes curl

Author: tianon

test/tests/logstash-basics/run.sh

@@ -8,8 +8,8 @@ dir="$(dirname "$(readlink -f "$BASH_SOURCE")")"
 
 image="$1"
 
-# Use the image being tested as our client image since it should already have curl
-clientImage="$image"
+# our image may not have "curl" (Alpine variants, for example)
+clientImage='buildpack-deps:jessie-curl'
 
 # input via HTTP (default port 0.0.0.0:8080)
 # output via stdout, newline-delimited nothing-but-the-message