How to import svn branches and tags into git-svn?

You'll need several steps.

1. supply proper trunk, branches and tags folder names and fetch svn repo:

   git svn init -t tags -b branches -T trunk https://mysvn.com/svnrepo
   git svn fetch
   

2. Since tags in svn are real branches, create git tags from tag branches:

   git for-each-ref --format="%(refname:short) %(objectname)" refs/remotes/tags |  cut -d / -f 3- |
   while read ref
   do
     echo git tag -a $ref -m 'import tag from svn'
   done
   

3. Delete tag branches

   git for-each-ref --format="%(refname:short)" refs/remotes/tags | cut -d / -f 2- |
   while read ref
   do 
     echo git branch -rd $ref
   done
   

4. Since tags marked in the previous step point to a commit "create tag", we need to derive "real" tags, i.e. parents of "create tag" commits.

   git for-each-ref --format="%(refname:short)" refs/tags |
   while read ref
   do
     tag=`echo $ref | sed 's/_/./g'` # give tags a new name
     echo $ref -\> $tag
     git tag -a $tag `git rev-list -2 $ref | tail -1` -m "proper svn tag"
   done
   

5. All we have to do now is to remove old tags.

This draws on Vanuan's answer above, but it preserves the message of the original svn tag in the new git tag.

$ git for-each-ref --format="%(refname:short) %(objectname)" refs/remotes/tags \
| while read BRANCH REF
  do
        TAG_NAME=${BRANCH#*/}
        BODY="$(git log -1 --format=format:%B $REF)"

        echo "ref=$REF parent=$(git rev-parse $REF^) tagname=$TAG_NAME body=$BODY" >&2

        git tag -a -m "$BODY" $TAG_NAME $REF^  &&\
        git branch -r -d $BRANCH
  done

This is the same as nicolai.rostov's answer above, but i just change the refs path I replaced refs/remotes/tags by refs/remotes/origin/tags I'm using git version 2.1.1 into cygwin terminal.

$ git for-each-ref --format="%(refname:short) %(objectname)" refs/remotes/origin/tags \
| while read BRANCH REF
  do
        TAG_NAME=${BRANCH#*/}
        BODY="$(git log -1 --format=format:%B $REF)"

        echo "ref=$REF parent=$(git rev-parse $REF^) tagname=$TAG_NAME body=$BODY" >&2

        git tag -a -m "$BODY" $TAG_NAME $REF^  &&\
        git branch -r -d $BRANCH
  done