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Validating k8s deployments using Sparrow
Let's create a sample nginx deployment to show how it works:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
spec:
selector:
matchLabels:
app: nginx
# replicas: 1 # tells deployment to run 2 pods matching the template
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
volumeMounts:
- mountPath: /var/www
name: www-data
env:
- name: DEMO_GREETING
value: "Hello from the environment"
- name: DEMO_FAREWELL
value: "Such a sweet sorrow"
volumes:
- name: www-data
persistentVolumeClaim:
claimName: nginx-exampleIn this example we run simple nginx application with local folder mounted as
/var/www and consuming it's data throughout a volume named www-data:k8s apply -f nginx.yaml
deployment.apps/nginx-deployment createdNow when our deployment is up and running, let's verify it, using Raku:
tomty --edit verify#!raku
task-run "chk-dpl", "k8s-deployment-check", %(
name => "nginx-deployment",
namespace => "melezhik-sandbox",
volume-mounts => %(
www-data => "/var/www"
),
);tomty verify[repository] :: index updated from file:///root/repo/api/v1/index
[chk-dpl] :: >>> verify deployment. name=nginx-deployment,namespace=melezhik-sandbox,container=nginx
[chk-dpl] :: [env_start]
[chk-dpl] :: [DEMO_GREETING=Hello from the environment]
[chk-dpl] :: [DEMO_FAREWELL=Such a sweet sorrow]
[chk-dpl] :: [env_end]
[chk-dpl] :: [volume_mounts_start]
[chk-dpl] :: [www-data /var/www]
[chk-dpl] :: [volume_mounts_end]
[chk-dpl] :: ==================================================================
[task check] >>> check volume mounts
[task check] stdout match (r) <[www-data /var/www]> TrueAs we could see Sparrow has successfully verified that
www-data mounted as /var/www folderWe can alter the scenario a bit, adding environment variable check as well:
tomty --edit verifytask-run "chk-dpl", "k8s-deployment-check", %(
name => "nginx-deployment",
namespace => "melezhik-sandbox",
volume-mounts => %(
www-data => "/var/www"
),
env => {
DEMO_GREETING => "Hello from the environment",
DEMO_FAREWELL => "Such a sweet sorrow"
},
);And now run:
tomty verify[repository] :: index updated from file:///root/repo/api/v1/index
[chk-dpl] :: >>> verify deployment. name=nginx-deployment,namespace=melezhik-sandbox,container=nginx
[chk-dpl] :: [env_start]
[chk-dpl] :: [DEMO_GREETING=Hello from the environment]
[chk-dpl] :: [DEMO_FAREWELL=Such a sweet sorrow]
[chk-dpl] :: [env_end]
[chk-dpl] :: [volume_mounts_start]
[chk-dpl] :: [www-data /var/www]
[chk-dpl] :: [volume_mounts_end]
[chk-dpl] :: ==================================================================
[task check] >>> check env
[task check] stdout match (r) <[DEMO_FAREWELL=Such a sweet sorrow]> True
[task check] stdout match (r) <[DEMO_GREETING=Hello from the environment]> True
[task check] >>> check volume mounts
[task check] stdout match (r) <[www-data /var/www]> TrueSparrow
k8s-deployment-check plugin allows one to test k8s infrastructure by just writing a simple piece of Raku code. The full documentation is available at SparrowHub site. I am going to add more features eventually.
Under the hood Sparrow uses Raku regular expressions to verify resources structure, this allows to write even more sophisticated checks.
For example, to check that a container run command has python 2nd or 3rd version one can write:
command => "regexp: '/usr/bin/python' 2|3"Stay tuned and as usual I'd like to hear your feedback
Alexey
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