NO-ISSUE: optimize build image size (#3500)

assisted-service-build image size gotten to 7GB, which impacts
developers environment (and running time).
This change aims to get rid of several redundant things:
1. Ignoring big files that sometimes local podman deployment creates
2. Removing installation of 7zip and EPEL

Author: Osher De Paz

.dockerignore

@@ -1 +1,5 @@
 build
+
+# Files used for onprem testing
+coreos-installer
+livecd.iso

Dockerfile.assisted-service-build

@@ -11,9 +11,8 @@ USER 0
 
 RUN mkdir build && chmod g+xw -R build/
 
-RUN yum install -y epel-release \
-    && yum install -y --setopt=skip_missing_names_on_install=False \
-        gcc genisoimage jq git libvirt-client libvirt-devel java
+RUN yum install -y --setopt=skip_missing_names_on_install=False \
+        gcc genisoimage git libvirt-client libvirt-devel java
 
 COPY --from=registry.ci.openshift.org/openshift/release:golang-1.17 /usr/bin/gotestsum /usr/bin/make /usr/bin/
 COPY --from=registry.ci.openshift.org/openshift/release:golang-1.17 /usr/local/go /usr/local/go

hack/setup_env.sh

@@ -39,6 +39,12 @@ function spectral() {
   chmod +x /usr/local/bin/spectral
 }
 
+function jq() {
+  echo "Installing jq..."
+  curl -L https://github.com/stedolan/jq/releases/download/jq-1.6/jq-linux64 --output /usr/local/bin/jq
+  chmod +x /usr/local/bin/jq
+}
+
 function butane() {
   echo "Installing butane..."
   curl https://mirror.openshift.com/pub/openshift-v4/clients/butane/latest/butane-${ARCH} --output /usr/local/bin/butane
@@ -53,10 +59,10 @@ function assisted_service() {
     install -o root -g root -m 0755 /tmp/kubectl /usr/local/bin/kubectl && \
     rm -f /tmp/kubectl
 
-  yum clean all && yum makecache
-  yum --disablerepo=epel -y update ca-certificates
   yum install -y --setopt=skip_missing_names_on_install=False \
-    docker podman awscli python3-pip genisoimage skopeo p7zip
+    docker podman awscli python3-pip genisoimage skopeo
+
+  jq
 
   butane