how to include bash in yaml so we can pass the value of output variable to yaml file-CodePudding

The below value of private_localaddress needs to passed to "range_start" in yaml file. how to do this ?

Here is the script:

#!/bin/bash
MAC=`curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/`
myarr=($MAC)

for val in ${myarr[@]}; do
   interfaceindex=`curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/$val/device-number`
   if [ $interfaceindex == 2 ];
   then
     private_localaddress=`curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/$val/local-ipv4s`
     echo $private_localaddress
   fi
done

Here is the YAML file :

---
apiVersion: "k8s.cni.cncf.io/v1"

kind: NetworkAttachmentDefinition

metadata:
  name: worker-private-eth2

spec:
  config: '{
    "cniVersion": "0.3.1",
    "ipam": {
      "type": "whereabouts",
      "range": "10.30.11.0/25",
      "range_start": $private_localaddress,
      "range_end": "10.30.11.127",
      "routes": [
        { "dst": "10.93.123.0/24", "gw": "10.30.11.1" }
      ],

Ffffff

CodePudding user response：

Perhaps the simplest would be to make private_localaddress an environment variable and use envsubst to apply the changes to your YAML.

However to end up with correct YAML code, you need to ensure that you have a quoted string to the right of the colon. The best would be if you can already ensure that your YAML is written as

"range_start": "$private_localaddress",

If this is not feasible, you have to add the quotes when creating the variable, i.e.

export private_localaddress=\"$(curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/$val/local-ipv4s)\"

CodePudding user response：

Use a proper yaml parser. Here are some examples:

Using mikefarah/yq:

value="$private_localaddress" yq \
  '.spec.config |= (fromjson | .ipam.range_start = strenv(value) | tojson)'

Using kislyuk/yq:

yq -y --arg value "$private_localaddress" \
  '.spec.config |= (fromjson | .ipam.range_start = $value | tojson)'

Using itchyny/gojq:

gojq --arg value "$private_localaddress" --yaml-input --yaml-output \
  '.spec.config |= (fromjson | .ipam.range_start = $value | tojson)'