Merge branch 'improve_bitbucket_docs' into 'master'

Improve BitBucket integration documentation [ci skip]

This MR will improve the BitBucket integration documentation by

- mentioning the need to reconfigure GitLab after changing the configuration file, if you're using the omnibus package.
- adding a section about configuring a Host entry for bitbucket.org.
- switching additional steps 1 and 2, because connecting to BitBucket will only work after you added the SSH key and the Host entry.
- using sudo for the ssh connection in step 2, so that it is more obvious, that the git account should be used to establish the connection.

See merge request !670

doc/integration/bitbucket.md

@@ -68,6 +68,8 @@ Bitbucket will generate an application ID and secret key for you to use.
 
 1.  Save the configuration file.
 
+1.  If you're using the omnibus package, reconfigure GitLab (```gitlab-ctl reconfigure```).
+
 1.  Restart GitLab for the changes to take effect.
 
 On the sign in page there should now be a Bitbucket icon below the regular sign in form.
@@ -80,43 +82,59 @@ To allow projects to be imported directly into GitLab, Bitbucket requires two ex
 
 Bitbucket doesn't allow OAuth applications to clone repositories over HTTPS, and instead requires GitLab to use SSH and identify itself using your GitLab server's SSH key.
 
-### Step 1: Known hosts
+### Step 1: Public key
 
-To allow GitLab to connect to Bitbucket over SSH, you need to add 'bitbucket.org' to your GitLab server's known SSH hosts. Take the following steps to do so:
+To be able to access repositories on Bitbucket, GitLab will automatically register your public key with Bitbucket as a deploy key for the repositories to be imported. Your public key needs to be at `~/.ssh/bitbucket_rsa.pub`, which will expand to `/home/git/.ssh/bitbucket_rsa.pub` in most configurations.
 
-1. Manually connect to 'bitbucket.org' over SSH, while logged in as the `git` account that GitLab will use:
+If you have that file in place, you're all set and should see the "Import projects from Bitbucket" option enabled. If you don't, do the following:
+
+1. Create a new SSH key:
 
     ```sh
-    ssh git@bitbucket.org
+    sudo -u git -H ssh-keygen
     ```
 
-1.  Verify the RSA key fingerprint you'll see in the response matches the one in the [Bitbucket documentation](https://confluence.atlassian.com/display/BITBUCKET/Use+the+SSH+protocol+with+Bitbucket#UsetheSSHprotocolwithBitbucket-KnownhostorBitbucket'spublickeyfingerprints) (the specific IP address doesn't matter):
+    When asked `Enter file in which to save the key` specify the correct path, eg. `/home/git/.ssh/bitbucket_rsa`.
+    Make sure to use an **empty passphrase**.
+
+1. Configure SSH client to use your new key:
+
+    Open the SSH configuration file of the git user.
 
     ```sh
-    The authenticity of host 'bitbucket.org (207.223.240.182)' can't be established.
-    RSA key fingerprint is 97:8c:1b:f2:6f:14:6b:5c:3b:ec:aa:46:46:74:7c:40.
-    Are you sure you want to continue connecting (yes/no)?
+      sudo editor /home/git/.ssh/config
     ```
 
-1. If the fingerprint matches, type `yes` to continue connecting and have 'bitbucket.org' be added to your known hosts.
+    Add a host configuration for `bitbucket.org`.
+
+    ```sh
+    Host bitbucket.org
+      IdentityFile ~/.ssh/bitbucket_rsa
+      User git
+    ```
 
-1. Your GitLab server is now able to connect to Bitbucket over SSH. Continue to step 2:
+### Step 2: Known hosts
 
-### Step 2: Public key
+To allow GitLab to connect to Bitbucket over SSH, you need to add 'bitbucket.org' to your GitLab server's known SSH hosts. Take the following steps to do so:
 
-To be able to access repositories on Bitbucket, GitLab will automatically register your public key with Bitbucket as a deploy key for the repositories to be imported. Your public key needs to be at `~/.ssh/bitbucket_rsa.pub`, which will expand to `/home/git/.ssh/bitbucket_rsa.pub` in most configurations.
+1. Manually connect to 'bitbucket.org' over SSH, while logged in as the `git` account that GitLab will use:
 
-If you have that file in place, you're all set and should see the "Import projects from Bitbucket" option enabled. If you don't, do the following:
+    ```sh
+    sudo -u git -H ssh bitbucket.org
+    ```
 
-1. Create a new SSH key:
+1.  Verify the RSA key fingerprint you'll see in the response matches the one in the [Bitbucket documentation](https://confluence.atlassian.com/display/BITBUCKET/Use+the+SSH+protocol+with+Bitbucket#UsetheSSHprotocolwithBitbucket-KnownhostorBitbucket'spublickeyfingerprints) (the specific IP address doesn't matter):
 
     ```sh
-    sudo -u git -H ssh-keygen
+    The authenticity of host 'bitbucket.org (207.223.240.182)' can't be established.
+    RSA key fingerprint is 97:8c:1b:f2:6f:14:6b:5c:3b:ec:aa:46:46:74:7c:40.
+    Are you sure you want to continue connecting (yes/no)?
     ```
 
-    When asked `Enter file in which to save the key` specify the correct path, eg. `/home/git/.ssh/bitbucket_rsa`.
-    Make sure to use an **empty passphrase**.
+1. If the fingerprint matches, type `yes` to continue connecting and have 'bitbucket.org' be added to your known hosts.
+
+1. Your GitLab server is now able to connect to Bitbucket over SSH.
 
-2. Restart GitLab to allow it to find the new public key.
+1. Restart GitLab to allow it to find the new public key.
 
 You should now see the "Import projects from Bitbucket" option on the New Project page enabled.