Ggtcf

lets take this example of a config map

apiVersion: v1
kind: ConfigMap
data:
 abc.yml: |-
<yml here>

Getting an error like failed to parse yaml to Json.

Create ConfigMap from file.

kubectl create configmap myconfig --from-file=youfile.yml.

You can check more examples on kubernetes docs

These could be the problems
1. most likely the issue could with the indentation.
2. remove '-' from abc.yml: |- and check

I followed the below steps and was able to load yaml file into configmap. it worked fine.

master $ cat c.yaml
apiVersion: v1
data:
 redis-config: |
 maxmemory 2mb
 maxmemory-policy allkeys-lru
kind: ConfigMap
metadata:
 name: example-redis-config

master $ kubectl create configmap testcfg --from-file=./c.yaml

master $ kubectl get cm testcfg -oyaml
apiVersion: v1
data:
 c.yaml: |
 apiVersion: v1
 data:
 redis-config: |
 maxmemory 2mb
 maxmemory-policy allkeys-lru
 kind: ConfigMap
 metadata:
 name: example-redis-config
kind: ConfigMap
metadata:
 creationTimestamp: 2019-03-07T08:35:18Z
 name: testcfg
 namespace: default
 resourceVersion: "7520"
 selfLink: /api/v1/namespaces/default/configmaps/testcfg
 uid: f033536d-40b3-11e9-a67d-0242ac11005b

Yes you can do that, but you should care about the syntax. You can also follow techniques for yaml from here.

If you use kubectl create configmap myconfig --from-file=abc.yml, then it is ok.

But if you write the whole yaml file for your configmap in myconfig.yaml and then run kubectl create -f myconfig.yaml, then you should care about syntax.

Say your abc.yml file is as followings:

a:
 b: b1
 c: c1
d: d1

Then write your myconfig.yaml file:

apiVersion: v1
kind: ConfigMap
data:
 abc.yml: |
 a:
 b: b1
 c: c1
 d: d1

Now just run kubectl create -f myconfig.yaml.
That's it.

Happy Kubernetes!!!.