I found a bunch of image files that has the wrong extension. Due to the way the website is made, they must have a .jpg extension. But some of them are png files.
So I made a quick list of fake JPEG files ls public/assets/image/*.jpg | xargs file --mime | grep -v jpeg and found https://stackoverflow.com/a/25825362/205696 that has an example of how to use the aws-cli tool to change the Cache-Control header (I want to change the Content-Type header).
According to the aws s3 sync help man page, the syntax is sync <LocalPath> <S3Uri> or <S3Uri> <LocalPath> or <S3Uri> <S3Uri>. Since I do not want to sync any files from my machine, I opt for the last syntax aws s3 sync <S3Uri> <S3Uri>.
However doing:
aws s3 sync s3://firefund-assets/underathens4.jpg s3://firefund-assets/underathens4.jpg --content-type image/png
does not seem to change anything. The underathens4.jpg file still has System defined Content-Type image/jpeg... and there is nothing written to stdout.
If I can change the meta-data for a file in S3, then I can simply do
cat fakeJpegs.txt | sed 's/public\/assets\/image\///' | xargs -i aws s3 sync s3://firefund-assets/'{}' s3://firefund-assets/'{}' --content-type image/png
I do not want to re-upload any files. In that case, I could use s3.console.aws.amazon.com and do the change manually. I just want to have a little script to do this occasionally..
Change the default content type on multiple files that have been uploaded to a AWS S3 bucket is related but suggest uploading the files again.
You can copy an object over itself while specifying new information.
Use the cp command rather than the sync command:
aws s3 cp s3://firefund-assets/file.jpg s3://firefund-assets/file.jpg --content-type image/png