How to wait until EXTERNAL-IP is assigned?

Question

When I deploy https://projectcontour.io/ ingress controller on my Digital Ocean K8S cluster, a load balancer gets created automatically.

I consider to use Ansible as management tool for K8S to automate the deployment.

After the following tasks:

- name: retrieve file
  get_url:
    url: https://projectcontour.io/quickstart/contour.yaml
    dest: /testing/contour.yaml
  register: download_contour

- name: create deployment
  k8s:
    src: /testing/deployment.yml
  when: download_contour.changed

I would like to wait until the contour gets EXTERNAL-IP address assigned, then continue with other tasks. Here is an example on my local computer:

kubectl get -n projectcontour service envoy -o wide                                                                       
NAME    TYPE           CLUSTER-IP     EXTERNAL-IP      PORT(S)                      AGE     SELECTOR
envoy   LoadBalancer   10.96.226.84   172.18.255.200   80:31092/TCP,443:30362/TCP   2d15h   app=envoy

How to wait until the envoy LoadBalancer gets the EXTERNAL-IP address assigned in Ansible?

joelazar · Accepted Answer · 2021-02-08T14:55:24.370

5

I haven't tested it, but I think you could try to do something like this:

- shell: if [[ $(kubectl get services envoy -n projectcontour --output jsonpath='{.status.loadBalancer.ingress[0]}') ]]; then exit 0; else exit 1; fi;
  register: wait_for_ext_ip
  until: wait_for_ext_ip.rc == 0
  retries: 10
  delay: 5

edited Feb 08 '21 at 14:55

answered Feb 08 '21 at 13:40

joelazar

733
4
12

Yes exactly. I didn't see this answer before I was working on mine. But this could work indeed. – Kevin C Feb 08 '21 at 14:27
What does `until: wait_for_ext_ip | success` mean? – softshipper Feb 08 '21 at 14:41
1

Should it be 0 instead sucess? – softshipper Feb 08 '21 at 14:42
How does the return structure from shell look like? – softshipper Feb 08 '21 at 14:50
ups, thanks, corrected to `wait_for_ext_ip.rc == 0` :) – joelazar Feb 08 '21 at 14:56

score 1 · Answer 2 · answered Feb 08 '21 at 14:25

You should use the until loops:

tasks:
  - name: run kubectl to retreive external IP - Wait for task to complete
    shell: "kubectl get -n projectcontour service envoy -o wide | awk '{ print $4}' |  grep -v EXT"
    register: k_ext_ip
    until: k_ext_ip.stdout.find("1.2.3.4") != -1
    retries: 6
    delay: 10

For the shell command, I simply used some basic linux commands. It's better to replace those with Kubectl aligned commands to view only the EXTERNAL-IP.

How to wait until EXTERNAL-IP is assigned?

2 Answers2