Install official find and sed in build-image

Signed-off-by: Marco Pracucci <marco@pracucci.com>

Author: pracucci

.circleci/config.yml

@@ -11,7 +11,7 @@ workflows:
 jobs:
   lint:
     docker:
-      - image: grafana/cortex-jsonnet-build-image:e19ece2
+      - image: grafana/cortex-jsonnet-build-image:3527936
     steps:
       - checkout
       - run:
@@ -26,7 +26,7 @@ jobs:
 
   build:
     docker:
-      - image: grafana/cortex-jsonnet-build-image:e19ece2
+      - image: grafana/cortex-jsonnet-build-image:3527936
     steps:
       - checkout
       - run: make build-mixin
@@ -35,7 +35,7 @@ jobs:
 
   test-readme:
     docker:
-      - image: grafana/cortex-jsonnet-build-image:e19ece2
+      - image: grafana/cortex-jsonnet-build-image:3527936
     steps:
       - checkout
       - run: make test-readme

build-image/Dockerfile

@@ -30,7 +30,7 @@ FROM golang:1.15-alpine AS mixtool-builder
 RUN GO111MODULE=on go get github.com/monitoring-mixins/mixtool/cmd/mixtool@ae18e31161ea10545b9c1ac0d23c10122f2c12b5
 
 FROM alpine:3.13
-RUN apk add --no-cache git make libgcc libstdc++ zip
+RUN apk add --no-cache git make libgcc libstdc++ zip findutils sed
 COPY --from=jsonnet-builder /usr/bin/jsonnetfmt /usr/bin
 COPY --from=jsonnet-builder /usr/bin/jsonnet /usr/bin
 COPY --from=jb-builder /usr/bin/jb /usr/bin