cannot call bash environment variable inside jq - bash

Question

In the below script, I am not able to successfully call the "repovar" variable in the jq command.
cat quayrepo.txt | while read line
do
export repovar="$line"
jq -r --arg repovar "$repovar" '.data.Layer| .Features[] | "\(.Name), \(.Version), $repovar"' severity.json > volume.csv
done
The script uses a text file to loop through the repo names
quayrepo.txt---> file has the list of names in this case the file has a value of "Reponame1"
sample input severity.json file:
{
"status": "scanned",
"data": {
"Layer": {
"IndexedByVersion": 3,
"Features": [
{
"Name": "elfutils",
"Version": "0.168-1",
"Vulnerabilities": [
{
"NamespaceName": "debian:9",
"Severity": "Medium",
"Name": "CVE-2016-2779"
}
]
}
]
}
}
}
desired output:
elfutils, 0.168-1, Medium, Reponame1
Required output: I need to retrieve the value of my environment variable as the last column in my output csv file

Answer 1

You need to surround $repovar with parenthesis, as the other values
repovar='qweqe'; jq -r --arg repovar "$repovar" '.data.Layer| .Features[] | "\(.Name), \(.Version), \($repovar)"' tmp.json
Result:
elfutils, 0.168-1, qweqe
There's no need for the export.

Answer 2

#!/usr/bin/env bash
while read line
do
jq -r --arg repovar "$line" '.data.Layer.Features[] | .Name + ", " + .Version + ", " + $repovar' severity.json
done < quayrepo.txt > volume.csv
with quayrepo.txt as
Reponame1
and severity.json as
{
"status": "scanned",
"data": {
"Layer": {
"IndexedByVersion": 3,
"Features": [
{
"Name": "elfutils",
"Version": "0.168-1",
"Vulnerabilities": [
{
"NamespaceName": "debian:9",
"Severity": "Medium",
"Name": "CVE-2016-2779"
}
]
}
]
}
}
}
produces volume.csv containing
elfutils, 0.168-1, Reponame1
To #peak's point, changing > to >> in ...severity.json >> volume.csv will create a multi-line csv instead of just overwriting until the last line

Answer 3

You don't need a while read loop in bash at all; jq itself can loop over your input lines, even when they aren't JSON, letting you run jq only once, not once per line in quayrepo.txt.
jq -rR --slurpfile inJson severity.json <quayrepo.txt >volume.csv '
($inJson[0].data.Layer | .Features[]) as $features |
[$features.Name, $features.Version, .] |
#csv
'
jq -R specifies raw input, letting jq directly read lines from quayrepo.txt into .
jq --slurpfile varname filename.json reads filename.json into an array of JSON objects parsed from that file. If the file contains only one object, one needs to refer to $varname[0] to refer to it.
#csv converts an array to a CSV output line, correctly handling data with embedded quotes or other oddities that require special processing.