Update pod push script to handle multiple edge cases (#2511)

Summary:
This PR adds a script to publish pods. It handles different edge cases like:
- The version was already pushed but still you are trying to push it, it will skip in that case and give a proper message.
- This also makes sure that the same version Flipper pod exists before pushing FlipperKit.
- It also has the retry mechanism in place if at all the pod trunk push fails to push.

## Changelog

Updated the workflow to push pods

Pull Request resolved: https://github.com/facebook/flipper/pull/2511

Test Plan:
While pushing already published release:
https://github.com/facebook/flipper/actions/runs/974346766

While pushing new release:

https://github.com/facebook/flipper/actions/runs/978707041

Reviewed By: passy

Differential Revision: D29415078

Pulled By: priteshrnandgaonkar

fbshipit-source-id: f0fb68a2e399802e5719d7be4216d4a5ed6ef782

scripts/publish-flipper-pods.sh

@@ -0,0 +1,97 @@
+#!/bin/bash
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+set -e
+
+if [ -z "$1" ]
+then
+    echo "Please pass the root directory of flipper repository as a first argument."
+    exit 1
+fi
+
+if [ -z "$2" ]
+then
+    echo "Please pass the pod name to push, It just accepts 'Flipper' and 'FlipperKit', do not append podspec at the end"
+    exit 1
+fi
+
+if [[ "$2" != "Flipper" ]] && [[ "$2" != "FlipperKit" ]]
+then
+    echo "This script just supports Flipper and FlipperKit pods. Please send either Flipper or FlipperKit as an argument."
+    exit 1
+fi
+
+FLIPPER_DIR=$1
+POD_NAME=$2
+POD_TO_PUSH="$FLIPPER_DIR/$POD_NAME.podspec"
+
+if ! [[ -f "$POD_TO_PUSH" ]]; then
+    echo "$POD_TO_PUSH does not exist. Please check the pod name."
+fi
+
+POD_VERSION_TAG=$(< "$POD_TO_PUSH" grep "flipperkit_version =" )
+POD_VERSION="${POD_VERSION_TAG##* }"
+POD_VERSION=$(sed -e "s/^'//" -e "s/'$//" <<<"$POD_VERSION")
+
+push_pods_and_retry () {
+    echo "Pushing $POD_VERSION of $POD_NAME..."
+    FLAGS="--use-libraries --allow-warnings --verbose --skip-import-validation"
+    if [[ "$POD_NAME" == "FlipperKit" ]]
+    then
+        FLAGS="$FLAGS --synchronous"
+    fi
+    POD_COMMAND="pod trunk push $POD_TO_PUSH $FLAGS"
+    MAX_ATTEMPT=4
+    ATTEMPT_NUM=0
+    TIME_TO_WAIT=1
+    until [ "$ATTEMPT_NUM" -ge "$MAX_ATTEMPT" ]
+    do
+        echo "Retry attempt $ATTEMPT_NUM..."
+        if [ "$ATTEMPT_NUM" -ge 1 ]
+        then
+        echo "Retry attempt $ATTEMPT_NUM..."
+        fi
+        $POD_COMMAND && break
+        echo "Failed to push. Will Retry in $TIME_TO_WAIT minute."
+        sleep $((60*TIME_TO_WAIT))
+        # Exponential back off.
+        TIME_TO_WAIT=$((2*TIME_TO_WAIT))
+        ATTEMPT_NUM=$((ATTEMPT_NUM+1))
+    done
+
+    if [ "$ATTEMPT_NUM" -ge "$MAX_ATTEMPT" ]
+    then
+        echo "Exhausted all retry attempts and failed to push, please try again later..."
+        exit 1
+    fi
+}
+
+ENDPOINT_TO_CHECK="https://github.com/CocoaPods/Specs/blob/master/Specs/a/e/a/Flipper/$POD_VERSION"
+if [[ "$POD_NAME" == "FlipperKit" ]]
+then
+    STATUS_CODE=$(curl -LI "$ENDPOINT_TO_CHECK" -o /dev/null -w '%{http_code}\n' -s)
+    if ! [[ $STATUS_CODE == 200 ]]
+    then
+    echo "Please push $POD_VERSION of Flipper before pushing $POD_VERSION of FlipperKit."
+    exit 1;
+    fi
+    ENDPOINT_TO_CHECK="https://github.com/CocoaPods/Specs/tree/master/Specs/3/2/5/FlipperKit/$POD_VERSION"
+fi
+
+echo "Verifying if $POD_VERSION already pushed for $POD_NAME..."
+echo "Curling $ENDPOINT_TO_CHECK"
+STATUS_CODE=$(curl -LI "$ENDPOINT_TO_CHECK" -o /dev/null -w '%{http_code}\n' -s)
+echo "$STATUS_CODE"
+
+if  [[ "$STATUS_CODE" -ge 400 ]]
+then
+    push_pods_and_retry "$@"
+else
+    echo "$POD_VERSION of $POD_NAME is already pushed."
+    exit 0
+fi
+
+echo "Successfully published $POD_VERSION of $POD_NAME."