Possibly found a problem after looking at this post: Device registration fails with open balena
The balenaRootCA stored in config.json is not the same as the certificate I receive with openssl s_client -connect api.openbalena.local:443. Maybe that could also clarify the errors in the vpn container?
Feb 18 15:09:33 5310aba944d1 haproxy[174]: Routing 172.21.0.1:56614@tcp-443 to vpn-workers/vpn1:41298 [C:1/1 Q:0/0 T:1/0]
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] TCP connection established with [AF_INET]127.0.0.1:41298
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] Socket flags: TCP_NODELAY=1 succeeded
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 TLS: Initial packet from [AF_INET]127.0.0.1:41298, sid=6b7a6e95 8c678615
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_VER=2.4.7
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_PLAT=linux
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_PROTO=2
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_NCP=2
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_LZ4=1
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_LZ4v2=1
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_LZO=1
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_COMP_STUB=1
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_COMP_STUBv2=1
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 peer info: IV_TCPNL=1
Feb 18 15:09:33 5310aba944d1 vpn[1011]: info: [vpn-8] AUTH FAIL: API Authentication failed for 85d0c4a33a5b40fcef8b65acfc4cfc43
Feb 18 15:09:33 5310aba944d1 vpn[1011]: ::ffff:127.0.0.1 - - [18/Feb/2021:15:09:33 +0000] "POST /api/v1/auth/ HTTP/1.1" 401 12 "-" "curl/7.64.0"
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 WARNING: Failed running command (--auth-user-pass-verify): external program exited with error status: 1
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 TLS Auth Error: Auth Username/Password verification failed for peer
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 Control Channel: TLSv1.3, cipher TLSv1.3 TLS_AES_256_GCM_SHA384
Feb 18 15:09:33 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 Peer Connection Initiated with [AF_INET]127.0.0.1:41298
Feb 18 15:09:35 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 PUSH: Received control message: 'PUSH_REQUEST'
Feb 18 15:09:35 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 Delayed exit in 5 seconds
Feb 18 15:09:35 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 SENT CONTROL [UNDEF]: 'AUTH_FAILED' (status=1)
Feb 18 15:09:35 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 Connection reset, restarting [0]
Feb 18 15:09:35 5310aba944d1 vpn[1011]: notice: [vpn-8.1] 127.0.0.1:41298 SIGUSR1[soft,connection-reset] received, client-instance restarting