[SOLVED] How to filter a particular line from terraform plan output

Issue

I am trying to put a shell script to check if there is a drift in terraform or not and I am filtering terraform plan to a variable and using grep trying to print if there is a drift. But echo is printing the whole variable output rather filtered output with grep condition.

i=environment
terraform init
tf_plan=$(terraform plan | grep -v "Refreshing state" | grep -v "data")
drift_check=`echo $tf_plan | grep -c 'to add\|to change\|to destroy'`
if [[ $drift_check -ge 1 ]]
then
   echo "Drift detected in environment $i"
   printf "%s:%s" "$i" "`echo $tf_plan | grep -E 'to add|to change|to destroy'`"
else
   echo "No drift detected in environment $i"
   printf "%s:%s" "$i" "`echo $tf_plan | grep -E 'No changes'`"
fi

ExpectedOutput assuming there is a drift

environment:Plan: 0 to add, 1 to change, 0 to destroy.

When I run these commands manually I am getting expected output like below

echo $tf_plan | grep -c 'to add\|to change\|to destroy'
1

echo $tf_plan | grep -E 'to add|to change|to destroy'
Plan: 0 to add, 1 to change, 0 to destroy.

printf "%s:%s" "$i":"`echo $tf_plan | grep -E 'to add|to change|to destroy'`"
environment:Plan: 0 to add, 1 to change, 0 to destroy

But through bash script its printing out whole terraform drift plan. Below is the output of tf_plan variable

echo $tf_plan

Terraform used the selected providers to generate the following execution
plan. Resource actions are indicated with the following symbols:
  ~ update in-place

Terraform will perform the following actions:

  # elasticstack_elasticsearch_index.idx1 will be updated in-place
  ~ resource "elasticstack_elasticsearch_index" "idx_salesorder_2019_v6" {
        id                     = "xyzadcfgd/idx1"
      ~ mappings               = jsonencode(
          ~ {
              ~ properties = {
                  ~ address            = {
                      ~ properties = {
                          ~ addressdetails = {
                              ~ properties = {
                                  - streetlocation      = {
                                      - fields = {
                                          - keyword = {
                                              - ignore_above = 256
                                              - type         = "keyword"
                                            }
                                        }
                                      - type   = "text"
                                    }
                                    # (30 unchanged attributes hidden)
                                }
                            }
                            # (1 unchanged attribute hidden)
                        }
                    }
                    # (3 unchanged attributes hidden)
                }
            }
        )
        name                   = "idx1"
        # (8 unchanged attributes hidden)

        # (9 unchanged blocks hidden)
    }
Plan: 0 to add, 1 to change, 0 to destroy.

Solution

You should add quotes to the $tf_plan variable, otherwise bash will print the variable content without the newlines, causing the grep to treat it as an entire line and match everything.

if [[ $drift_check -ge 1 ]]
then
   echo "Drift detected in environment $i"
   printf "%s:%s" "$i" "`echo "$tf_plan" | grep -E 'to add|to change|to destroy'`" # <-- tf_plan quoted here
else
   echo "No drift detected in environment $i"
   printf "%s:%s" "$i" "`echo "$tf_plan" | grep -E 'No changes'`"
fi

Answered By - opeonikute

Answer Checked By - Mildred Charles (WPSolving Admin)