JQ, two queries, over different part of json, Merge it back - jq

Question

I am trying to extract kubeconfig data with jq.
kubectl config view --raw -o json | jq ...
There is a json produced of this kind:
{
"kind": "Config",
"apiVersion": "v1",
"preferences": {},
"clusters": [
{
"name": "some-name",
"cluster": {
"server": "https://some-url",
"certificate-authority-data": "some-cert"
}
},
{
"name": "another-name",
"cluster": {
"server": "https://another-url",
"certificate-authority-data": "another-cert"
}
}
],
"users": [
{
"name": "some-name",
"user": {
"username": "some-user",
"password": "some-password"
}
},
{
"name": "another-name",
"user": {
"username": "another-user",
"password": "another-password"
}
}
],
"contexts": [],
"current-context": "some-context"
}
Question #1:
For a given name ,"some-name", I'd like to extract json:
{
url: "https://some-url",
cert: "some-cert",
username: "some-user",
password: "some-password"
}
Question #2:
"users" sub-section can have other format
"users": [
{
"name": "...",
"user": {
"exec": {
...
}
Where .user.username or .user.password or both can be missing
In this case overall query should return "{}", even though, "clusters" query/branch has result
Question 3, as a follow up to Jeff Mercado answer:
I want to get all clusters, joined (grouped by) name:
Looking at the manual, https://stedolan.github.io/jq/manual/#Builtinoperatorsandfunctions ,
section "Multiplication, division, modulo: *, /, and %", example:
jq '{"k": {"a": 1, "b": 2}} * {"k": {"a": 0,"c": 3}}' => {"k": {"a": 0, "b": 2, "c": 3}}'
gives presumably right result, assuming "k" is value of "name". So, grouping by "k", merging (*) the results.
I produced following query:
echo "${json}" | jq -r '(.clusters[] | {(.name): {url: .cluster.server, cert: .cluster["certificate-authority-data"]}}) * (.users[] | {(.name): {user: .user.username, password: .user.password}})'
First part returns {"name": {url: cert}}, second part is {"name": {username, password}}
However, result is not merge as in jq Manual, but something else ... product ?
{
"some-name": {
"url": "https://some-url",
"cert": "some-cert",
"user": "some-user",
"password": "some-password"
}
}
{
"another-name": {
"url": "https://another-url",
"cert": "another-cert"
},
"some-name": {
"user": "some-user",
"password": "some-password"
}
}
{
"some-name": {
"url": "https://some-url",
"cert": "some-cert"
},
"another-name": {
"user": "another-user",
"password": "another-password"
}
}
{
"another-name": {
"url": "https://another-url",
"cert": "another-cert",
"user": "another-user",
"password": "another-password"
}
}
Why/what is it ? Kind of following idea of the product ('*') but not of the jq tutorial as I (most likely, incorrectly) understand it
Experimentation:
I have 2 queries now producing partial result.
Let's grab original json (above) in and parse:
read -d '' json << EOF
...
EOF
queries:
echo "${json}" | jq -r '.clusters[] | select(.name=="some-name") | .cluster | {url: .server, cert: .["certificate-authority-data"]}' &&\
echo "${json}" | jq -r '.users[] | select(.name=="some-name") | .user | {user: .username, password: .password}'
Will produce the split output:
{
"url": "https://some-url",
"cert": "some-cert"
}
{
"user": "some-user",
"password": "some-password"
}
Or, with key added for further merge:
echo "${json}" | jq -r '.clusters[] | select(.name=="some-name") | {name: .name, url: .cluster.server, cert: .cluster["certificate-authority-data"]}' &&\
echo "${json}" | jq -r '.users[] | select(.name=="some-name") | {name: .name, user: .user.username, password: .user.password}'
Will produce:
{
"name": "some-name",
"url": "https://some-url",
"cert": "some-cert"
}
{
"name": "some-name",
"user": "some-user",
"password": "some-password"
}
"name" is not needed but can be used as a join operation

Answer 1

So you already know how to get the cluster and user by name separately, first step is to select them both within a single filter:
(.clusters[] | select(.name == $name).cluster), (.users[] | select(.name == $name).user)
This will yield two separate objects, the cluster, then the user. But we want to merge them. There's plenty of ways to do this. You could add them (+) directly or merge them (*) but no real difference there. You'll just want to remap the properties to the names you wanted where needed.
(.clusters[] | select(.name == $name).cluster | {url: .server, cert: ."certificate-authority-data"})
+
(.users[] | select(.name == $name).user | {username, password})
Pass the name in as a parameter to your filter;
$ kubectl config view --raw -o json | jq --arg name some-name '
(.clusters[] | select(.name == $name).cluster | {url: .server, cert: ."certificate-authority-data"})
+
(.users[] | select(.name == $name).user | {username, password})
'
For the second part of your question, if it turns out the mapped user is missing key properties and you want to omit them, just add another select filter to the end to test for those properties and replace with an empty object if nothing is found:
... | select(has("username") and has("password")) // {}
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