Intermittent issue fetching keys

[Deleted user]

I tried the same docker build... twice and it crashed trying to retrieve keys:

+ gpg --keyserver ha.pool.sks-keyservers.net --recv-keys 79F7026C690BAA50B92CD8B66A3AD3F4F22C4FED
gpg: requesting key F22C4FED from hkp server ha.pool.sks-keyservers.net
gpgkeys: key 79F7026C690BAA50B92CD8B66A3AD3F4F22C4FED can't be retrieved

I worked around it by modifying the code to try twice:

 	for key in $GPG_KEYS; do \
-		gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys "$key"; \
+		gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys "$key" || gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys "$key"; \
 	done; \

Then it built successfully for me.

Back in 2016 a similar gpg error happened in an automated build:
docker-library/official-images#2445
(search that page for: can't be retrieved)

[wglambert]

docker-library/official-images#4252 (comment)

TLDR; GPG servers are extremely flaky . . .

This is what we do for GPG issues docker-library/official-images#4252 (comment)