3

I am using salt for last one month. Whenever I run a command say sudo salt '*' test.ping, then the master pings all the minions and the response being the list of all the minions which are up and running. Output looks something like:

{
"minion_1": true
}
{
"minion_2": true
}
{
"minion_3": true
}

In the master's conf file, return type is configured to JSON. But if I execute an incorrect command through salt master say sudo salt '*' test1.ping, then the master returns something like this 

{
"minion_1": "'test1.ping' is not available."
}
{
"minion_2": "'test1.ping' is not available."
}
{
"minion_3": "'test1.ping' is not available."
}

In both the outputs displayed above, the command has given a success exit code on the master's shell/terminal. How do we track which minions were not able to execute the commands. I am not interested in what type of error it is, I just need some or the other way to track the minions which failed to execute the command.

The last solution is to write a parser which will read the complete output and decide for itself. Hope that there is a better solution.

uvsmtid
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Paritosh
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2 Answers2

3

Reasons to despair

I would not rely on Salt's CLI exit code at the moment (version 2014.7.5) - there are still many issues opened to solve this.

Get valid JSON output

There is --static option which fixes JSON output:

If using --out=json, you will probably want --static as well. Without the static option, you will get a JSON string for each minion.

Otherwise the output given by Salt above contains multiple objects (one per minion) which is not a valid JSON (JSON requires single object, array or value per document) and simple way of loading entire output by a standard JSON parser will fail. It is even mentioned in documentation (as of 5188d6c):

Some JSON parsers can guess when an object ends and a new one begins but many can not.

In addition to that, some Salt options (like show_jid) also send strings to STDOUT which mixes it with execution report and invalidates JSON output format. Option --static also solves this problem.

UPDATE: Parser to detect failure in Salt execution

This problem squeezed me so much so I gave quick birth to this Python script @ 75e42af with example how it is used @ b819961d.

NOTE: This won't address output of arbitrary Salt command (including test.ping above), but issues related to the output of state execution are covered. There is still a solution to test.ping problem above - it can be run from state, then the output can be analysed by the script. See how to call an execution module from within a state or *.sls file in this answer.

Features (details in the code itself):

  • Handle output from both highstate and orchestrate runners.
  • Handle output of multiple minions and any number of commands.
  • Report summary "? of N" and overall result.
  • Standalone file usable as script and module.

The only limitation is that it requires JSON output (Salt option --out json) simply because it is easy to fix the discussed issues before feeding it to parser.

Community
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uvsmtid
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0

The above parser will only work for test.ping command. If multiple commands have to be executed we will have to write a more robust parser.

Inder Kumar Rathore
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Somesh Chadda
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