Use bash ranges "{1..3}" instead of "$(seq 1 3)".

cluster/aws/util.sh

@@ -1547,7 +1547,7 @@ function ssh-to-node {
 
   local ip=$(get_ssh_hostname ${node})
 
-  for try in $(seq 1 5); do
+  for try in {1..5}; do
     if ssh -oLogLevel=quiet -oConnectTimeout=30 -oStrictHostKeyChecking=no -i "${AWS_SSH_KEY}" ${SSH_USER}@${ip} "echo test > /dev/null"; then
       break
     fi

cluster/gce/util.sh

@@ -1533,7 +1533,7 @@ function ssh-to-node {
   local node="$1"
   local cmd="$2"
   # Loop until we can successfully ssh into the box
-  for try in $(seq 1 5); do
+  for try in {1..5}; do
     if gcloud compute ssh --ssh-flag="-o LogLevel=quiet" --ssh-flag="-o ConnectTimeout=30" --project "${PROJECT}" --zone="${ZONE}" "${node}" --command "echo test > /dev/null"; then
       break
     fi

cluster/gke/util.sh

@@ -339,7 +339,7 @@ function ssh-to-node() {
   local node="$1"
   local cmd="$2"
   # Loop until we can successfully ssh into the box
-  for try in $(seq 1 5); do
+  for try in {1..5}; do
     if gcloud compute ssh --ssh-flag="-o LogLevel=quiet" --ssh-flag="-o ConnectTimeout=30" --project "${PROJECT}" --zone="${ZONE}" "${node}" --command "echo test > /dev/null"; then
       break
     fi

cluster/photon-controller/util.sh

@@ -284,7 +284,7 @@ function pc-create-vm {
 
    # Wait for the VM to be started and connected to the network
   have_network=0
-  for i in $(seq 120); do
+  for i in {1..120}; do
     # photon -n vm networks print several fields:
     # NETWORK MAC IP GATEWAY CONNECTED?
     # We wait until CONNECTED is True

examples/k8petstore/k8petstore-loadbalancer.sh

@@ -230,7 +230,7 @@ $kubectl create -f bps-load-gen-rc.json --namespace=$NS
 #This script assumes the cloud provider is able to create a load balancer. If this not the case, you may want to check out other ways to make the frontend service accessible from outside (https://github.com/kubernetes/kubernetes/blob/master/docs/services.md#external-services)
 function getIP {
   echo "Waiting up to 1 min for a public IP to be assigned by the cloud provider..."
-  for i in `seq 1 20`;
+  for i in {1..20};
   do
     PUBLIC_IP=$($kubectl get services/frontend --namespace=$NS -o template --template="{{range .status.loadBalancer.ingress}}{{.ip}}{{end}}")
       if [ -n "$PUBLIC_IP" ]; then
@@ -249,7 +249,7 @@ function pollfor {
   pass_http=0
 
   ### Test HTTP Server comes up.
-  for i in `seq 1 150`;
+  for i in {1..150};
   do
       ### Just testing that the front end comes up.  Not sure how to test total entries etc... (yet)
       echo "Trying curl ... $PUBLIC_IP:3000 , attempt $i . expect a few failures while pulling images... "

examples/k8petstore/k8petstore-nodeport.sh

@@ -267,7 +267,7 @@ function pollfor {
   pass_http=0
 
   ### Test HTTP Server comes up.
-  for i in `seq 1 150`;
+  for i in {1..150};
   do
       ### Just testing that the front end comes up.  Not sure how to test total entries etc... (yet)
       echo "Trying curl frontend:3000 via $TEST_IP:$NODE_PORT, attempt ${i}. Expect a few failures while pulling images... "

examples/k8petstore/k8petstore.sh

@@ -233,7 +233,7 @@ function pollfor {
   pass_http=0
 
   ### Test HTTP Server comes up.
-  for i in `seq 1 150`;
+  for i in {1..150};
   do
       ### Just testing that the front end comes up.  Not sure how to test total entries etc... (yet)
       echo "Trying curl ... $PUBLIC_IP:3000 , attempt $i . expect a few failures while pulling images... "

hack/jenkins/e2e-runner.sh

@@ -236,7 +236,7 @@ fi
 if [[ -n "${CLOUDSDK_BUCKET:-}" ]]; then
     # Retry the download a few times to mitigate transient server errors and
     # race conditions where the bucket contents change under us as we download.
-    for n in $(seq 3); do
+    for n in {1..3}; do
         gsutil -mq cp -r "${CLOUDSDK_BUCKET}" ~ && break || sleep 1
         # Delete any temporary files from the download so that we start from
         # scratch when we retry.

hack/jenkins/upload-to-gcs.sh

@@ -86,7 +86,7 @@ function upload_version() {
   fi
 
   local -r json_file="${gcs_build_path}/started.json"
-  for upload_attempt in $(seq 3); do
+  for upload_attempt in {1..3}; do
     echo "Uploading version to: ${json_file} (attempt ${upload_attempt})"
     gsutil -q -h "Content-Type:application/json" cp -a "${gcs_acl}" <(
       echo "{"
@@ -103,7 +103,7 @@ function upload_artifacts_and_build_result() {
   local -r build_result=$1
   echo -n 'Run finished at '; date -d "@${timestamp}"
 
-  for upload_attempt in $(seq 3); do
+  for upload_attempt in {1..3}; do
     echo "Uploading to ${gcs_build_path} (attempt ${upload_attempt})"
     echo "Uploading build result: ${build_result}"
     gsutil -q -h "Content-Type:application/json" cp -a "${gcs_acl}" <(

hack/make-rules/test-cmd.sh

@@ -110,7 +110,7 @@ function kubectl-with-retry()
 {
   ERROR_FILE="${KUBE_TEMP}/kubectl-error"
   preserve_err_file=${PRESERVE_ERR_FILE-false}
-  for count in $(seq 0 3); do
+  for count in {0..3}; do
     kubectl "$@" 2> ${ERROR_FILE} || true
     if grep -q "the object has been modified" "${ERROR_FILE}"; then
       kube::log::status "retry $1, error: $(cat ${ERROR_FILE})"
@@ -694,7 +694,7 @@ runTests() {
   ## If the resourceVersion is the same as the one stored in the server, the patch will be applied.
   # Command
   # Needs to retry because other party may change the resource.
-  for count in $(seq 0 3); do
+  for count in {0..3}; do
     resourceVersion=$(kubectl get "${kube_flags[@]}" pod valid-pod -o go-template='{{ .metadata.resourceVersion }}')
     kubectl patch "${kube_flags[@]}" pod valid-pod -p='{"spec":{"containers":[{"name": "kubernetes-serve-hostname", "image": "nginx"}]},"metadata":{"resourceVersion":"'$resourceVersion'"}}' 2> "${ERROR_FILE}" || true
     if grep -q "the object has been modified" "${ERROR_FILE}"; then