I am using following command to fetch all release tags from mysql on docker hub :

wget -q https://registry.hub.docker.com/v1/repositories/mysql/tags -O - | jq -r .[].name

Output is:

5.7.38
5.7.38-debian
5.7.38-oracle
5.7.4
5.7.4-m14
5.7.5
5.7.5-m15
5.7.6
5.7.6-m16
5.7.7
5.7.7-rc
5.7.8
5.7.8-rc
5.7.9
8
8-debian
8-oracle
8.0
8.0-debian
8.0-oracle
8.0.0
8.0.1
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.28
8.0.28-debian
8.0.28-oracle
8.0.29
8.0.29-debian
8.0.29-oracle
8.0.3
8.0.4
8.0.4-rc
debian
oracle

Is there a way i can fetch the latest stable version only? For example , i want to fetch 8.0.29 as it is the latest stable version for 8x version . And next time when 8.0.30 comes i get the output from the same command?

Can anybody please help or point me to right direction? I tried using xidel but could not find solution

CodePudding user response：

The latest version has the latest tag. "stable" is in the eye of the beholder and not computable with the given information.

CodePudding user response：

Extract any sequence of digits using scan("\\d "), convert the strings to numbers using tonumber, and use that as argument for sort_by on the initial array, from which you can then output the last item using index -1.

jq -r 'map(.name) | sort_by(scan("\\d ") | tonumber)[-1]'

8.0.29-oracle

Demo

---

If for the output you only want the pure version number (8.0.29 instead of 8.0.29-oracle), ditch everything after and including the dash sign:

jq -r 'map(.name | .[:index("-")]) | sort_by(scan("\\d ") | tonumber)[-1]'

8.0.29

Demo

CodePudding user response：

I tried using xidel but could not find solution

If you're still interested, it's not that hard:

$ xidel -s "https://registry.hub.docker.com/v1/repositories/mysql/tags" -e '
  (
    for $x in $json()/name[matches(.,"^\d \.\d \.\d $")]
    order by $x
    return $x
  )[last()]
'
8.0.29

• [matches(.,"^\d \.\d \.\d $")] returns only those names with just digits.
• order by $x for sorting.
• (...)[last()] to return the last item of the sequence (in this case the latest version).

Alternatively and even shorter, you can use max():

$ xidel -s "https://registry.hub.docker.com/v1/repositories/mysql/tags" -e '
  max($json()/name[matches(.,"^\d \.\d \.\d $")])
'
8.0.29