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Improve json patch example.

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Jeffrey Regan
2020-04-03 18:34:02 -07:00
parent 0f3d5c80e4
commit eb57d4b510
1 changed files with 130 additions and 53 deletions
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examples/jsonpatch.md
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@@ -2,19 +2,17 @@
A kustomization file supports customizing resources via [JSON patches](https://tools.ietf.org/html/rfc6902).
The example below modifies an `Ingress` object with such a patch.
Make a place to work:
Make a `kustomization` containing an ingress resource.
<!-- @createIngress @testAgainstLatestRelease -->
<!-- @placeToWork @testAgainstLatestRelease -->
```
DEMO_HOME=$(mktemp -d)
```
cat <<EOF >$DEMO_HOME/kustomization.yaml
resources:
- ingress.yaml
EOF
We'll be editting an `Ingress` object:
<!-- @ingress @testAgainstLatestRelease -->
```
cat <<EOF >$DEMO_HOME/ingress.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
@@ -25,94 +23,173 @@ spec:
- host: foo.bar.com
http:
paths:
- backend:
- path: /
backend:
serviceName: homepage
servicePort: 8888
- path: /api
backend:
serviceName: my-api
servicePort: 80
servicePort: 7701
- path: /test
backend:
serviceName: hello
servicePort: 7702
EOF
```
Declare a JSON patch file to update two fields of the Ingress object:
The edits we want to make are:
- change host from `foo.bar.com` to `foo.bar.io`
- change servicePort from `80` to `8080`
- change the value of `host` to _foo.bar.io_
- change the port for `'/'` from _8888_ to _80_
- insert an entirely new serving path `/healthz`
at a particular point in the `paths` list,
rather than at the end or the beginning.
Here's the patch file to do that:
<!-- @addJsonPatch @testAgainstLatestRelease -->
```
cat <<EOF >$DEMO_HOME/ingress_patch.json
[
{"op": "replace", "path": "/spec/rules/0/host", "value": "foo.bar.io"},
{"op": "replace", "path": "/spec/rules/0/http/paths/0/backend/servicePort", "value": 8080}
{"op": "replace",
"path": "/spec/rules/0/host",
"value": "foo.bar.io"},
{"op": "replace",
"path": "/spec/rules/0/http/paths/0/backend/servicePort",
"value": 80},
{"op": "add",
"path": "/spec/rules/0/http/paths/1",
"value": { "path": "/healthz", "backend": {"servicePort":7700} }}
]
EOF
```
You can also write the patch in YAML format. This example also shows the "add" operation:
We'll of course need a `kustomization` file
referring to the `Ingress`:
<!-- @addYamlPatch @testAgainstLatestRelease -->
<!-- @kustomization @testAgainstLatestRelease -->
```
cat <<EOF >$DEMO_HOME/ingress_patch.yaml
- op: replace
path: /spec/rules/0/host
value: foo.bar.io
- op: add
path: /spec/rules/0/http/paths/-
value:
path: '/test'
backend:
serviceName: my-test
servicePort: 8081
cat <<EOF >$DEMO_HOME/kustomization.yaml
resources:
- ingress.yaml
EOF
```
Apply the patch by adding _patchesJson6902_ field in kustomization.yaml
To this same `kustomization` file, add a
`patchesJson6902` field refering to
the patch file we just made and
target it to the `Ingress` object:
<!-- @applyJsonPatch @testAgainstLatestRelease -->
```
cat <<EOF >>$DEMO_HOME/kustomization.yaml
patchesJson6902:
- target:
- path: ingress_patch.json
target:
group: networking.k8s.io
version: v1beta1
kind: Ingress
name: my-ingress
path: ingress_patch.json
EOF
```
Running `kustomize build $DEMO_HOME`, in the output confirm that host has been updated correctly.
<!-- @confirmHost @testAgainstLatestRelease -->
Define the expected output:
<!-- @expected @testAgainstLatestRelease -->
```
test 1 == \
$(kustomize build $DEMO_HOME | grep "host: foo.bar.io" | wc -l); \
echo $?
```
Running `kustomize build $DEMO_HOME`, in the output confirm that the servicePort has been updated correctly.
<!-- @confirmServicePort @testAgainstLatestRelease -->
```
test 1 == \
$(kustomize build $DEMO_HOME | grep "servicePort: 8080" | wc -l); \
echo $?
cat <<EOF >$DEMO_HOME/out_expected.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: my-ingress
spec:
rules:
- host: foo.bar.io
http:
paths:
- backend:
serviceName: homepage
servicePort: 80
path: /
- backend:
servicePort: 7700
path: /healthz
- backend:
serviceName: my-api
servicePort: 7701
path: /api
- backend:
serviceName: hello
servicePort: 7702
path: /test
EOF
```
If the patch is YAML-formatted, it will be parsed correctly:
Run the build:
<!-- @runIt @testAgainstLatestRelease -->
```
kustomize build $DEMO_HOME >$DEMO_HOME/out_actual.yaml
```
<!-- @applyYamlPatch @testAgainstLatestRelease -->
Confirm they match:
<!-- @diffShouldExitZero @testAgainstLatestRelease -->
```
diff $DEMO_HOME/out_actual.yaml $DEMO_HOME/out_expected.yaml
```
Let's further edit the same `Ingress` object,
but using a patch written in YAML instead of JSON.
<!-- @writeYamlPatch @testAgainstLatestRelease -->
```
cat <<EOF >$DEMO_HOME/ingress_patch.yaml
- op: add
path: /spec/rules/0/http/paths/-
value:
path: '/canada'
backend:
serviceName: hoser
servicePort: 7703
EOF
```
Now add this to the list of patches in the `kustomization` file:
<!-- @addYamlPatch @testAgainstLatestRelease -->
```
cat <<EOF >>$DEMO_HOME/kustomization.yaml
patchesJson6902:
- target:
- path: ingress_patch.yaml
target:
group: networking.k8s.io
version: v1beta1
kind: Ingress
name: my-ingress
path: ingress_patch.yaml
EOF
```
<!-- @confirmYamlPatch @testAgainstLatestRelease -->
We expect the following at the end of the output:
<!-- @expected @testAgainstLatestRelease -->
```
test 1 == \
$(kustomize build $DEMO_HOME | grep "path: /test" | wc -l); \
echo $?
cat <<EOF >$DEMO_HOME/out_expected.yaml
- backend:
serviceName: hello
servicePort: 7702
path: /test
- backend:
serviceName: hoser
servicePort: 7703
path: /canada
EOF
```
Try it:
<!-- @runIt @testAgainstLatestRelease -->
```
kustomize build $DEMO_HOME | tail -n 8 |\
diff $DEMO_HOME/out_expected.yaml -
```