*.sh: Set sane bash options on shell scripts

Adding the following accross the project:

```bash
/# exit immediately when a command fails
set -e
/# only exit with zero if all commands of the pipeline exit successfully
set -o pipefail
/# error on unset variables
+set -u

```

contrib/kube-prometheus/experimental/custom-metrics-api/gencerts.sh

@@ -1,4 +1,10 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 # Detect if we are on mac or should use GNU base64 options
 case $(uname) in

contrib/kube-prometheus/hack/example-service-monitoring/deploy

@@ -1,3 +1,9 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 kubectl apply -f examples/example-app

contrib/kube-prometheus/hack/example-service-monitoring/teardown

@@ -1,3 +1,9 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 kubectl delete -f examples/example-app

hack/concat-kubernetes-manifests.sh

@@ -1,4 +1,10 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 # Concatenate all files with "---" because that's how to specify multiple
 # Kubernetes manifests in one file. Because the first `awk` also adds "---" in

hack/generate-bundle.sh

@@ -1,4 +1,9 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 hack/concat-kubernetes-manifests.sh example/rbac/prometheus-operator/*.yaml > bundle.yaml
-

hack/generate/build-non-rbac-prometheus-operator.sh

@@ -1,3 +1,9 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 jsonnet -J hack/generate/vendor hack/generate/prometheus-operator-non-rbac.jsonnet | gojsontoyaml > example/non-rbac/prometheus-operator.yaml

hack/generate/build-rbac-prometheus-operator.sh

@@ -1,4 +1,10 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 rm -rf tmp
 mkdir tmp

hack/run-external.sh

@@ -1,4 +1,10 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 if [[ -z "$1" ]]; then
 	echo "missing cluster name"

hack/show-image.sh

@@ -1,3 +1,9 @@
-#!/bin/bash
+#!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 kubectl get pods --all-namespaces -l app="${1}" -ojsonpath="{.items[*].spec.containers[?(@.name==\"$1\")].image}"

hack/show-rules.sh

@@ -1,3 +1,9 @@
-#!/bin/bash
+#!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 kubectl -n prometheus-operator-e2e-tests exec -it prometheus-test-0 -c prometheus '/bin/sh -c "cat /etc/prometheus/rules/rules-0/test.rules"'

scripts/check_license.sh

@@ -1,4 +1,10 @@
 #!/usr/bin/env bash
+# exit immediately when a command fails
+set -e
+# only exit with zero if all commands of the pipeline exit successfully
+set -o pipefail
+# error on unset variables
+set -u
 
 licRes=$(
     find . -type f -iname '*.go' ! -path '*/vendor/*' -exec \