Environment:
OS:ubuntu_18_04_64
Docker:Docker version 19.03.2, build 6a30dfc

Prysm: prysmaticlabs/prysm-beacon-chain:latest

Geth: ethereum/client-go:latest

Containers:

1. two containers are running on the same machine;
2. docker run -d -v /mnt/prysm:/data -p 4000:4000 -p 13000:13000 -p 12000:12000/udp --name beacon-node prysmaticlabs/prysm-beacon-chain --datadir=/data --jwt-secret=/data/jwtsecret --execution-endpoint=http://localhost:8551  --accept-terms-of-use=true;
3. docker run -d --name ethereum --restart always 
-p 8545:8545 -p 30303:30303 -p 8546:8546 -p 8551:8551 
-v /mnt/blockchain_data/eth:/root/.ethereum ethereum/client-go 
--http --http.addr "0.0.0.0" --http.port 8545 --http.api "eth,personal,net,web3,db,txpool,ws" 
--ws --ws.addr "0.0.0.0" --ws.origins "*" --ws.port "8546" 
--authrpc.jwtsecret "/root/.ethereum/geth/jwtsecret" 
--syncmode=snap --cache=1024 --maxpeers=50

configurations:
1.JWT on both nodes;
2. based on Prysm official guide, port 8551 mapping on geth node;
3. test localhost:8551 via nc -z -v and the connection successful;

After running two containers:

1. beacon node logs: time=”2022-09-16 05:38:19″ level=error msg=”Could not connect to execution client endpoint” error=”Post “http://localhost:8551”: dial tcp 127.0.0.1:8551: connect: connection refused: Post “http://localhost:8551″: dial tcp 127.0.0.1:8551: connect: connection refused” prefix=powchain;