# The authenticity of host 'app.example.com (xxx.xxx.xx.xxx)' can't be established **URL:** \ **Category:** Build Environment\ **Tags:** 2.0, rails\ **Created:** [August 6, 2018, 4:57pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085 "2018-08-06T16:57:22Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![aruprakshit](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/aruprakshit/32/7881_2.png) [@aruprakshit](https://discuss.circleci.com/u/aruprakshit)\ **Post date:** [August 6, 2018, 4:57pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/1 "2018-08-06T16:57:22Z")
My _config.yml_ looks like: ``` version: 2.0 jobs: build: environment: BUNDLE_PATH: vendor/bundle docker: - image: circleci/ruby:2.3-node-browsers environment: DATABASE_HOST: 127.0.0.1 DATABASE_USER: ubuntu DATABASE_PASSWORD: "" RAILS_ENV: test RACK_ENV: test - image: circleci/postgres:9.6-alpine-postgis environment: POSTGRES_USER: ubuntu working_directory: ~/code steps: - checkout # Download and cache dependencies - restore_cache: keys: - v1-dependencies-{{ checksum "Gemfile.lock" }} # fallback to using the latest cache if no exact match is found - v1-dependencies- - run: name: install dependencies environment: BUNDLE_JOBS: 4 BUNDLE_RETRY: 3 command: | bundle check || bundle install - save_cache: paths: - ./vendor/bundle key: v1-dependencies-{{ checksum "Gemfile.lock" }} - run: name: Copy config command: | cp config/database.yml.example config/database.yml - run: name: Run unit tests command: | bundle exec rake db:create bundle exec rake db:test:prepare bundle exec rake test - add_ssh_keys: fingerprints: - "31:6b:xx:6d:xx:bf:1c:xx:ad" - deploy: name: Deploying command: | echo $CIRCLE_BRANCH if ["${CIRCLE_BRANCH}" == "master"]; then bundle exec mina deploy TO=production fi if ["${CIRCLE_BRANCH}" == "staging"]; then bundle exec mina deploy TO=staging fi ``` But while deploy command runs, I get stuck like below: > The authenticity of host ‘[app.example.com](http://app.example.com) (xxx.xxx.xx.xxx)’ can’t be established. > ED25519 key fingerprint is SHA256:iXXXXXXXlK90OfsYmk. > Are you sure you want to continue connecting (yes/no)? mina aborted! I did what is said in [Adding an SSH Key to CircleCI](https://circleci.com/docs/2.0/add-ssh-key/) , still no luck. Any help what am I missing? ---
**Author:** ![halfer](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/halfer/32/9083_2.png) [@halfer](https://discuss.circleci.com/u/halfer)\ **Post date:** [August 6, 2018, 5:41pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/2 "2018-08-06T17:41:42Z")
Search the forum, that error has come up a few times 🙂 ---
**Author:** ![aruprakshit](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/aruprakshit/32/7881_2.png) [@aruprakshit](https://discuss.circleci.com/u/aruprakshit)\ **Post date:** [August 6, 2018, 5:58pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/3 "2018-08-06T17:58:28Z")
I did before I post. Found several tips, and I am looking for if there is any documentation on this. The documentation I followed didn’t solve my problem. ---
**Author:** ![halfer](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/halfer/32/9083_2.png) [@halfer](https://discuss.circleci.com/u/halfer)\ **Post date:** [August 6, 2018, 7:31pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/4 "2018-08-06T19:31:22Z")
I doubt there’d be official CircleCI documentation; general usage problems tend not to appear in docs, which are much more about things going right! I suppose it is conceivable that it could go in a FAQ though. However, as I say, I think it has been covered here. Further tips to try: - log in via SSH and try running the command on the console to debug the issue - Use verbose flags in your SSH command to get some log output to debug why SSH keys are not working - Let us know what key algo you are using - it looks like you are using ED25519. I seem to recall one of the posts here saying that something worked (RSA?), and something else (ED25519?) did not. [See this search](https://discuss.circleci.com/search?q=ed25519). ---
**Author:** ![aruprakshit](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/aruprakshit/32/7881_2.png) [@aruprakshit](https://discuss.circleci.com/u/aruprakshit)\ **Post date:** [August 7, 2018, 10:58am UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/5 "2018-08-07T10:58:39Z")
I was reading this [Permissions and access during deployment](https://circleci.com/docs/1.0/permissions-and-access-during-deployment/). I have added private key of my hose to the settings page, as name `app.example.com`, so `cat ~/.ssh/config` should have an entry like `IdentityFile /home/circleci/.ssh/id_rsa_app.example.com` as per the documentation, but I see like: ``` circleci@fbe0ad158caf:~$ cat ~/.ssh/config Host app.example.com IdentitiesOnly yes IdentityFile /home/circleci/.ssh/id_rsa_316b7b5a6d0dd0f207fc739dbf1c07ad circleci@fbe0ad158caf:~$ ``` Do you think it might be the issue? When I try to SSH from circle container I get this [log](https://gist.github.com/aruprakshit/d88f4020d54d65231f1a20d87eff5e98) . ---
**Author:** ![halfer](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/halfer/32/9083_2.png) [@halfer](https://discuss.circleci.com/u/halfer)\ **Post date:** [August 7, 2018, 11:04am UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/6 "2018-08-07T11:04:49Z")
Possibly. That looks like something that CircleCI would have set up. I’m assuming that you’re doing a checkout from one place (e.g. GitHub) and deploying to another (e.g. Digital Ocean). Thus, there should not be a name clash, since it should be differentiated by the `Host`. However, yes, if you are deploying to `app.example.com` and the config points to a key you did not intend, then work out how the config got like that, and see if you can append to it or replace it (depending on whether CircleCI needs it again for another step). ---
**Author:** ![aruprakshit](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/aruprakshit/32/7881_2.png) [@aruprakshit](https://discuss.circleci.com/u/aruprakshit)\ **Post date:** [August 7, 2018, 1:58pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/7 "2018-08-07T13:58:43Z")
I found a [thread](https://discuss.circleci.com/t/ssh-connection-from-circleci-build-server-to-remote-server-not-being-allowed/22964/22) discussing the same. But it was not completed, so not sure how the OP solved it. ---
**Author:** ![geidivan](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/geidivan/32/17780_2.png) [@geidivan](https://discuss.circleci.com/u/geidivan)\ **Post date:** [August 8, 2018, 8:28pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/8 "2018-08-08T20:28:02Z")
Try this command before connect to host: ssh-keyscan -H [app.example.com](http://app.example.com) \>\> ~/.ssh/known\_hosts ---
**Author:** ![aruprakshit](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/aruprakshit/32/7881_2.png) [@aruprakshit](https://discuss.circleci.com/u/aruprakshit)\ **Post date:** [August 9, 2018, 1:20pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/9 "2018-08-09T13:20:07Z")
> [@geidivan](#): > > [app.example.com](http://app.example.com) \> I tried what you said. But not sure why am I getting public key denied error. ``` #!/bin/bash -eo pipefail ssh-keyscan -H app.example.com > >> ~/.ssh/known_hosts echo $CIRCLE_BRANCH if ["${CIRCLE_BRANCH}" == "master"]; then bundle exec mina deploy TO=production fi if ["${CIRCLE_BRANCH}" == "staging"]; then bundle exec mina deploy TO=staging fi # app.example.com >:22 SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8 # app.example.com >:22 SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8 # app.example.com >:22 SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8 master Warning: Permanently added the ED25519 host key for IP address '139.200.66.160' to the list of known hosts. Permission denied (publickey). ! Run Error Exited with code 1 ``` ---
**Author:** ![Cormac](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/cormac/32/18955_2.png) [@Cormac](https://discuss.circleci.com/u/Cormac)\ **Post date:** [August 9, 2018, 6:22pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/10 "2018-08-09T18:22:46Z")
I would suggest authorizing a different key, removing the current key, and adding the newly authorized key back through the CircleCI interface. I’m not entirely sure why this happens, but in my own personal use I’ve found this resolved the problem. ---
**Author:** ![system](https://global.discourse-cdn.com/circleci/original/3X/5/1/511608acda8e85906e15909b57bd0a46c1dbe291.png) [@system](https://discuss.circleci.com/u/system)\ **Post date:** [November 7, 2018, 6:22pm UTC](https://discuss.circleci.com/t/the-authenticity-of-host-app-example-com-xxx-xxx-xx-xxx-cant-be-established/24085/11 "2018-11-07T18:22:47Z")
Closed on November 7, 2018, 6:22pm UTC This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.