Show EC2 instance tags for all instances

Show EC2 instance tags from single AWS account

$ aws ec2 describe-instances | jq -r '.Reservations[].Instances[].Tags | reduce .[] as $i ({}; .[$i.Key] += $i.Value) | [.Name, .Env, .Service, .Role] | @csv'

Show EC2 instance tags from multiple AWS accounts

$ ./run-aws-cli-on-multiple-acconts -r administrator -c "ec2 describe-instances" -j '.Reservations[].Instances[].Tags | reduce .[] as $i ({}; .[$i.Key] += $i.Value) | [.Name, .Env, .Service, .Role] | @csv'

account1 arn:aws:iam::123456789012:role/qwert-administrator-role

account2 arn:aws:iam::234567890123:role/qwert-administrator-role

See for run-aws-cli-on-multiple-acconts script.



並行処理(Concurrent Processing)


並列処理(Parallel Processing)



通常、コンピュータプログラムは休む暇なく次から次へと処理を実行するが、どうしても休まざるを得ないこともある。代表的なのが I/O だ。ユーザーの入力を待つ、ファイルへの書き込みを待つ、ネットワーク経由でデータを取得する、タイマーの設定時間を待つなど、CPU とは桁違いに遅い処理を実行するときに待ちが発生する。

このときにじっと待つのが同期処理(Synchronous Processing)で、一時的に中断して別の処理に実行の機会を譲るのが非同期処理(Asynchronous Processing)である。

How to fix "Failed to parse the manifest file" errors on Xcode

Sometimes I encounter ununderstandable Xcode build errors. It says “Failed to parse the manifest file”, “Missing package product ‘Xxxxxxxx’, Package resolution errors must be fixed before building”. I got this error, maybe once in a month in average. This error is hard to fix and time consuming.

How to fix “Failed to parse the manifest file” errors (definitive)

Remove all packages and re-adding again. This should fix all the package problems! But it changes project.pbxproj file. The good news is, after you get a stable build on Xcode, you can discard the project.pbxproj changes. You do not need to commit the file to Git or other VCSs.

How to fix “Failed to parse the manifest file” errors (obsoleted)

Aug. 13, 2022 updated: This section is obsoleted.

1. Close the project.

2. Quit Xcode.

3. Remove the contents of DerivedData folders and the Cache folder.

$ rm -rf ~/Library/Developer/Xcode/DerivedData/
$ rm -rf ~/Library/Caches/org.swift.swiftpm/

4. Run xcodebuild on the project folder.

$ xcodebuild -resolvePackageDependencies -project YourProject.xcodeproj -scheme YourScheme -platform="iOS, name:'Any iOS Device'"

- You must change "YourProject" and "YourScheme" for your environment.
- "Any iOS Device" can be your real device names and your simulator names.

$ xcodebuild -resolvePackageDependencies -project Product1.xcodeproj -scheme Staging -platform="iOS, name:'iPhone X (14.5)'"

5. Open Xcode.

6. Open the project.

7. Last magic. Change package version rule. Small change would be fine. For example, changing minimum version requirement from 5.4.0 to 5.4.1, or changing to exact version number which is different from current package version.



Search values in Redis DB

Redis is a key-value store, so there’s no way to query values in Redis database efficiently. One way is getting all keys by keys * and get values by get or mget one by one.

Another way, here I’ll describe in this post is, dumping all data to a file and converting it into JSON format, and find values using standard text edntir or grep or something like that.

Dump Redis data

If you use your own installation of Redis, you can get a dump file by save command. The backup file is located on a directory which you can know by config get command.

$ reids-cli -h
xxxxxx:6379> config get dir
1) "dir"
2) "/var/lib/redis/"
xxxxxx:6379> save

In my case, I use AWS ElastiCache. I dump the file using Backup operation and Copy it to a S3 Bucket.

Redis Rdbtools

Redis Rdbtools parses Redis dump.rdb files and export data to JSON.

rdb --command json ~/Downloads/dump.rdb

Shows only HTTP headers using wget

$ wget --server-response -q -O /dev/null
  HTTP/1.1 301 Moved Permanently
  Content-Type: text/html; charset=UTF-8
  Date: Thu, 14 Apr 2022 12:32:15 GMT
  Expires: Sat, 14 May 2022 12:32:15 GMT
  Cache-Control: public, max-age=2592000
  Server: gws
  Content-Length: 219
  X-XSS-Protection: 0
  X-Frame-Options: SAMEORIGIN
  HTTP/1.1 200 OK
  Date: Thu, 14 Apr 2022 12:32:15 GMT
  Expires: -1
  Cache-Control: private, max-age=0
  Content-Type: text/html; charset=ISO-8859-1
  P3P: CP="This is not a P3P policy! See for more info."
  Server: gws
  X-XSS-Protection: 0
  X-Frame-Options: SAMEORIGIN
  Set-Cookie: 1P_JAR=2022-04-14-12; expires=Sat, 14-May-2022 12:32:15 GMT; path=/;; Secure
  Set-Cookie: AEC=AVQQ_LCpx-4W71lh8_3ECluG4NGgHifEQOKmzq1HUoxOXzVhMI2_1kJUZH8; expires=Tue, 11-Oct-2022 12:32:15 GMT; path=/;; Secure; HttpOnly; SameSite=lax
  Set-Cookie: NID=511=bjcmwzEIZBBzgndiP7ba_4mZ_oxbOCCNfMT5UIvnAi7Cf17x_qq_wprw5wD-l8A_M2-qYem_tYS_E86Crg710qdOJQnWoJvUow2d1ljItFVS8zFD045noq6yvGOoA7cGEc4j-gJ9UFr5sU8JdmdCltwrPnpK4R5pumEXXLCjiGM; expires=Fri, 14-Oct-2022 12:32:15 GMT; path=/;; HttpOnly
  Accept-Ranges: none
  Vary: Accept-Encoding
  Transfer-Encoding: chunked

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