Better compact_plan script

sed wasn't cutting it with terraform 0.14 changes

image/Dockerfile

@@ -10,5 +10,6 @@ COPY tools/convert_output.py /usr/local/bin/convert_output
 COPY tools/plan_cmp.py /usr/local/bin/plan_cmp
 COPY tools/convert_version.py /usr/local/bin/convert_version
 COPY tools/workspace_exists.py /usr/local/bin/workspace_exists
+COPY tools/compact_plan.py /usr/local/bin/compact_plan
 
 LABEL org.opencontainers.image.title="GitHub actions for terraform"

image/entrypoints/apply.sh

@@ -38,7 +38,7 @@ function plan() {
         2>"$PLAN_DIR/error.txt" \
         | $TFMASK \
         | tee /dev/fd/3 \
-        | sed '1,/---/d' \
+        | compact_plan \
             >"$PLAN_DIR/plan.txt"
 
     PLAN_EXIT=${PIPESTATUS[0]}

image/entrypoints/plan.sh

@@ -19,7 +19,7 @@ set +e
     2>"$PLAN_DIR/error.txt" \
     | $TFMASK \
     | tee /dev/fd/3 \
-    | sed '1,/---/d' \
+    | compact_plan \
         >"$PLAN_DIR/plan.txt"
 
 readonly TF_EXIT=${PIPESTATUS[0]}

image/tools/compact_plan.py

@@ -0,0 +1,25 @@
+#!/usr/bin/python3
+
+import sys
+
+if __name__ == '__main__':
+    plan = False
+    buffer = []
+
+    for line in sys.stdin.readlines():
+
+        if not plan and (
+            line.startswith('An execution plan has been generated and is shown below') or
+            line.startswith('No changes') or
+            line.startswith('Error')
+        ):
+            plan = True
+
+        if plan:
+            sys.stdout.write(line)
+        else:
+            buffer.append(line)
+
+    if not plan and buffer:
+        for line in buffer:
+            sys.stdout.write(line)

tests/plan/plan_11/main.tf

@@ -5,3 +5,7 @@ resource "random_string" "my_string" {
 output "s" {
   value = "string"
 }
+
+terraform {
+  required_version = "~> 0.11.0"
+}

tests/plan/plan_12/main.tf

@@ -5,3 +5,7 @@ resource "random_string" "my_string" {
 output "s" {
   value = "string"
 }
+
+terraform {
+  required_version = "~> 0.12.0"
+}

tests/plan/plan_13/main.tf

@@ -5,3 +5,7 @@ resource "random_string" "my_string" {
 output "s" {
   value = "string"
 }
+
+terraform {
+  required_version = "~> 0.13.0"
+}

tests/plan/plan_14/main.tf

@@ -5,3 +5,7 @@ resource "random_string" "my_string" {
 output "s" {
   value = "string"
 }
+
+terraform {
+  required_version = "~> 0.14.0"
+}