From 9517059ae0098d52da7f0ffab76db5f2894351aa Mon Sep 17 00:00:00 2001
From: dkistner <dominickistner@yahoo.de>
Date: Tue, 14 Jul 2020 14:25:49 +0200
Subject: [PATCH] Support terraform imports

---
 example/10-config.yaml                 |  2 ++
 example/50-terraformer-import-pod.yaml | 41 +++++++++++++++++++++++
 terraform.sh                           | 46 ++++++++++++++++++++++++++
 3 files changed, 89 insertions(+)
 create mode 100644 example/50-terraformer-import-pod.yaml

diff --git a/example/10-config.yaml b/example/10-config.yaml
index 18a520f9..bb0dc2e5 100644
--- a/example/10-config.yaml
+++ b/example/10-config.yaml
@@ -43,6 +43,8 @@ data:
       description = "AWS Secret Access Key"
       type        = "string"
     }
+  # imports: |
+  #   aws_route53_record.www Z3ABCDE5FGHIJK.example.com
 
 ---
 apiVersion: v1
diff --git a/example/50-terraformer-import-pod.yaml b/example/50-terraformer-import-pod.yaml
new file mode 100644
index 00000000..ddf148d4
--- /dev/null
+++ b/example/50-terraformer-import-pod.yaml
@@ -0,0 +1,41 @@
+# Copyright (c) 2019 SAP SE or an SAP affiliate company. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---
+apiVersion: v1
+kind: Pod
+metadata:
+  name: some-name.infra.tf-import
+  namespace: default
+spec:
+  activeDeadlineSeconds: 1800
+  containers:
+  - name: terraform
+    image: eu.gcr.io/gardener-project/gardener/terraformer:latest
+    imagePullPolicy: IfNotPresent
+    command:
+    - /terraformer.sh
+    - import
+    env:
+    - name: TF_CONFIGURATION_CONFIG_MAP_NAME
+      value: some-name.infra.tf-config
+    - name: TF_STATE_CONFIG_MAP_NAME
+      value: some-name.infra.tf-state
+    - name: TF_VARIABLES_SECRET_NAME
+      value: some-name.infra.tf-vars
+    resources:
+      requests:
+        cpu: 100m
+  restartPolicy: Never
+  terminationGracePeriodSeconds: 30
diff --git a/terraform.sh b/terraform.sh
index 96405c94..6ac24275 100755
--- a/terraform.sh
+++ b/terraform.sh
@@ -20,6 +20,7 @@ DIR_CONFIGURATION="/tf"
 DIR_VARIABLES="/tfvars"
 DIR_PROVIDERS="/terraform-providers"
 DIR_PLUGIN_BINARIES=".terraform/plugins/linux_amd64"
+DIR_IMPORTS="/terraform-imports"
 
 PATH_STATE_CONFIG_MAP="$DIR_STATE_OUT/$TF_STATE_CONFIG_MAP_NAME"
 PATH_STATE_IN="$DIR_STATE_IN/terraform.tfstate"
@@ -27,6 +28,9 @@ PATH_STATE_OUT="$DIR_STATE_OUT/terraform.tfstate"
 PATH_CONFIGURATION_MAINTF="$DIR_CONFIGURATION/main.tf"
 PATH_CONFIGURATION_VARIABLESTF="$DIR_CONFIGURATION/variables.tf"
 PATH_VARIABLES="$DIR_VARIABLES/terraform.tfvars"
+PATH_IMPORTS="$DIR_IMPORTS/terraform_imports"
+PATH_IMPORT_TMP_STATE_IN="/import_in_tmp_terraform.tfstate"
+PATH_IMPORT_TMP_STATE_OUT="/import_out_tmp_terraform.tfstate"
 
 NAMESPACE="$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace)"
 
@@ -65,6 +69,7 @@ mkdir -p "$DIR_CONFIGURATION"
 mkdir -p "$DIR_VARIABLES"
 mkdir -p "$DIR_STATE_IN"
 mkdir -p "$DIR_STATE_OUT"
+mkdir -p "$DIR_IMPORTS"
 
 # live lookup of terraform resources stored in configmaps
 echo "Fetching configmap $NAMESPACE/$TF_CONFIGURATION_CONFIG_MAP_NAME and storing data in $PATH_CONFIGURATION_MAINTF..."
@@ -81,6 +86,13 @@ kubectl \
   --output="jsonpath={.data['variables\.tf']}" \
   > "$PATH_CONFIGURATION_VARIABLESTF"
 
+echo "Fetching configmap $NAMESPACE/$TF_CONFIGURATION_CONFIG_MAP_NAME and storing data in $PATH_IMPORTS..."
+kubectl \
+  --namespace="$NAMESPACE" \
+  get configmap "$TF_CONFIGURATION_CONFIG_MAP_NAME" \
+  --output="jsonpath={.data['imports']}" \
+  > "$PATH_IMPORTS"
+
 echo "Fetching secret $NAMESPACE/$TF_VARIABLES_SECRET_NAME and storing data in $PATH_VARIABLES..."
 kubectl \
   --namespace="$NAMESPACE" \
@@ -210,6 +222,40 @@ else
     TF_PID=$!
     wait $TF_PID
     exitcode=$?
+  elif [[ "$command" == "import" ]]; then
+    cat $PATH_STATE_IN > $PATH_IMPORT_TMP_STATE_IN
+    while read -r line; do
+      [[ "$line" == '' ]] && continue
+      resource_ref="$(echo $line | cut -d ' ' -f1 | tr -d ' ')"
+      resource_value="$(echo $line | cut -d ' ' -f2 | tr -d ' ')"
+
+      terraform \
+        import \
+        -config="$DIR_CONFIGURATION" \
+        -state="$PATH_IMPORT_TMP_STATE_IN" \
+        -state-out="$PATH_IMPORT_TMP_STATE_OUT" \
+        -var-file="$PATH_VARIABLES" \
+        "$resource_ref" "$resource_value" &
+      TF_PID=$!
+      wait $TF_PID
+      exitcode=$?
+
+      [[ "$exitcode" == "0" ]] && cat $PATH_IMPORT_TMP_STATE_OUT > $PATH_IMPORT_TMP_STATE_IN
+    done < "$PATH_IMPORTS"
+    rm -f $PATH_IMPORT_TMP_STATE_IN
+
+    if [[ -f $PATH_IMPORT_TMP_STATE_OUT ]]; then
+      echo "Patching configmap $NAMESPACE/$TF_CONFIGURATION_CONFIG_MAP_NAME to remove imports as they are applied to state..."
+      kubectl \
+      --namespace="$NAMESPACE" \
+      patch configmap "$TF_CONFIGURATION_CONFIG_MAP_NAME" \
+      --type=json \
+      -p='[{"op": "remove", "path": "/data/imports"}]'
+
+      echo "Write the state containing import(s) for persisting to $PATH_STATE_OUT"
+      cat $PATH_IMPORT_TMP_STATE_OUT > $PATH_STATE_OUT
+      rm -f $PATH_IMPORT_TMP_STATE_OUT
+    fi
   else
     # Delete trap handler - nothing to do
     trap - HUP INT QUIT PIPE TERM EXIT