[SOLVED] Invalid JSON text passed

Issue

I am having a problem merging json files via ssh. I always get the error

jq: invalid JSON text passed to --argjson
Use jq --help for help with command-line options,
or see the jq manpage, or online docs  at https://stedolan.github.io/jq

Even though I pass a vlid json text.

# check if the content of the input file is valid JSONn  
if ! echo "$content" | jq empty > /dev/null 2>&1; then                                               
    echo "ERROR: The content of the input file is not valid JSON."
    exit 1                                                                                        
fi                                                                
                                                 
# extract the text inside the curly brackets from the JSON content                  
extracted_content=$(echo "$content" | jq .)    
  
# check if the extracted content is valid JSON                       
if ! echo "$extracted_content" | jq empty > /dev/null 2>&1; then              
    echo "ERROR: The content of the input file contains no or invalid curly braces."  
    exit 1                                                  
fi                                                                

while read ip 
do                                                                                                                         
        echo "Doing changes to machine $ip"
                                                                            
        # --- Connect to machine ---        

                 
        cd /home/root/.ssh                                                                 
        ssh -tt -o StrictHostKeyChecking=no -i sac_key root@${ip} -p22222 <<- _connect_      

        # --- Append the extracted content to the target JSON ---                       
        if ! jq --argjson data "$extracted_content" '. += $data' "$TO" > "$TO.tmp"; then
           echo "ERROR: Error appending content to destination JSON." 
           exit 1                                       
        fi    

        # --- Rename the temporary file to the original target ---
        mv "$TO.tmp" "$TO"     
_connect_                   
done < $1

So I tried to change the line

if ! jq --argjson data "$extracted_content" '. += $data' "$TO" > "$TO.tmp"; then

like doing only $extracted_content or like $(cat $extracted_content). Or showing me the contenct of $extracted_content with echo

extracted conent before ssh =
{"ntpServers":"10.9.221.1"}

Also using a json validator (https://jsonformatter.net/json-validator/) to check if the file is valid.

Solution

The answer by @Phillippe is good, but not perfect, because it requires you to escape the code in your heredoc yourself. Better practice is to have the shell do that escaping for you: Write the code you want to run remotely in a function, then tell the shell to serialize that function with declare -f just the same as how you serialize the data the function uses with declare -p.

remote_function() {

    # --- Append the extracted content to the target JSON ---
    jq --argjson data "$extracted_content" '. += $data' "$TO" > "$TO.tmp" || {
       rc=$?
       echo "ERROR: Error appending content to destination JSON." 
       exit "$rc"
    }

    # --- Rename the temporary file to the original target ---
    mv "$TO.tmp" "$TO"
}

ssh -tt -o StrictHostKeyChecking=no -i sac_key root@"$ip" -p22222 <<-_connect_
  $(declare -p extracted_content TO)  # define remote variables
  $(declare -f remote_function)       # define remote function
  remote_function                     # call remote function
_connect_                   

Answered By - Charles Duffy

Answer Checked By - Pedro (WPSolving Volunteer)