With the following Dockerfile:

FROM nexylan/php-dev:7.1-alpine

COPY entrypoint.sh /
RUN chmod u+x /entrypoint.sh
ENTRYPOINT ["/entrypoint.sh"]


CMD ["tail", "-f", "/dev/null"]

(The entrypoint does nothing related to the issue).

And the definition on docker-compose:

version: '2'

    image: alpine
      - .:/code

    build: docker/php-console
      - data
      - .env

If I run on my local Ubuntu computer:

docker-compose up -d
docker-compose exec -T console ssh -o StrictHostKeyChecking=no -i tests/fixtures/ssh/key -T [email protected]

It will work with the following message:

Hi xXx! You've successfully authenticated, but GitHub does not provide shell access.

But not on my GitLab CI runner instance, with the following configuration:

image: docker

  - docker:dind

  - docker info
  - apk add --update bash python py-pip python-dev
  - pip install docker-compose
  - ./configure
  - docker-compose up -d
  - docker-compose ps
  - docker-compose exec -T console make install

  - test

  stage: test
  tags: [docker-privileged]
    - echo ${SSH_PRIVATE_KEY} > tests/fixtures/ssh/key
    - echo ${SSH_PUBLIC_KEY} > tests/fixtures/ssh/key.pub
    - chmod 600 tests/fixtures/ssh/*
    - docker-compose exec -T console ls -l tests/fixtures/ssh/
    - docker-compose exec -T console ssh -o StrictHostKeyChecking=no -i tests/fixtures/ssh/key -T -vvv [email protected]

The keys are here and are exactly the same as my local, but the command fail to connect with the following -vvv log result:

OpenSSH_7.2p2-hpn14v4, OpenSSL 1.0.2k  26 Jan 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug2: resolving "github.com" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to github.com [] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file tests/fixtures/ssh/key type 1
debug1: key_load_public: No such file or directory
debug1: identity file tests/fixtures/ssh/key-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2p2-hpn14v4
debug1: Remote protocol version 2.0, remote software version libssh_0.7.0
debug1: no match: libssh_0.7.0
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to github.com:22 as 'git'
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: [email protected],[email protected],[email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected],zlib
debug2: compression stoc: none,[email protected],zlib
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: host key algorithms: ssh-dss,ssh-rsa
debug2: ciphers ctos: [email protected],aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,blowfish-cbc
debug2: ciphers stoc: [email protected],aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,blowfish-cbc
debug2: MACs ctos: hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,zlib,[email protected]
debug2: compression stoc: none,zlib,[email protected]
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ssh-rsa
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ssh-rsa SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8
Warning: Permanently added 'github.com,' (RSA) to the list of known hosts.
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug2: key: tests/fixtures/ssh/key (0x56053d865c20), explicit
debug3: send packet: type 5
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: tests/fixtures/ssh/key
debug3: send_pubkey_test
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 60
debug1: Server accepts key: pkalg ssh-rsa blen 279
debug2: input_userauth_pk_ok: fp SHA256:3aoR/R1oBDYb0QucuGCJfBgIWW4DE2P4DjuWwgtQg/k
debug3: sign_and_send_pubkey: RSA SHA256:3aoR/R1oBDYb0QucuGCJfBgIWW4DE2P4DjuWwgtQg/k
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug2: no passphrase given, try next key
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey).

I already tried this solution for /dev/tty issue, but no success!

Plus, as it's a Docker image, the environment should be the same, should not be? Why this is working on my local computer and not GitLab CI runner?

1 Answer 1


On your ubuntu you're presumably connected as a local tty whereas the GitLab CI docker has no tty exactly as the error implies.

When you use the command

docker-compose exec -T

This disables the allocation of a ptty therefor openssh sees no tty to gather input from for keyboard interactive passwords. https://docs.docker.com/compose/reference/exec/ The server requested this during the handshake so the ssh client will attempt to do it.

Because the -d option was not used this command will use the existing tty if there is one which explains why it works on your local Ubuntu machine where a tty would likely automatically be created.

  • It looks right, but I have to use this option. Otherwise, it will produce something like this: pastebin.com/nDcp2k26 Plus, the ssh key does not need a passphrase. Can't we avoid the pty usage? Dec 24, 2017 at 12:14
  • Well, I figured out how to make it working, but now it's always asking for a passphrase. It's an another issue IMO so: unix.stackexchange.com/q/412827/173927 Dec 24, 2017 at 16:26
  • 1
    @Soullivaneuh Given the information in your question I can only say the server is asking for a keyboard interactive password. I'm not sure how you were able to bypass it in other instances. Also it does the same thing for me when I try it.
    – jdwolf
    Dec 24, 2017 at 19:28
  • Why the server would ask for a password when the connection come form GitLab and not form my computer? It makes no sense. :-/ Dec 26, 2017 at 15:51
  • 1
    @Soullivaneuh It's just how they decided to configure their server. Who knows.
    – jdwolf
    Dec 27, 2017 at 22:44

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