Were the apostles in full agreement on all doctrine? 

Answer:

"Doctrine" means teachings. Jesus told his apostles, "But when He, the Spirit of truth, comes, He will guide you into all the truth; for He will not speak on His own initiative, but whatever He hears, He will speak; and He will disclose to you what is to come. He will glorify Me, for He will take of Mine and will disclose it to you. All things that the Father has are Mine; therefore I said that He takes of Mine and will disclose it to you" (John 16:13-15). Therefore, what the apostles taught all came from the Holy Spirit. God doesn't tell one person one thing and another person something else. One of the unique features of the Bible is that despite being written by over 40 people over a 1,500 year period, the writings are consistent. You would expect this when the source of the material comes from the God who cannot lie (Titus 1:2). Paul mentioned that even the words were selected for them. "Now we have received, not the spirit of the world, but the Spirit who is from God, so that we may know the things freely given to us by God, which things we also speak, not in words taught by human wisdom, but in those taught by the Spirit, combining spiritual thoughts with spiritual words" (I Corinthians 2:12-13).

People who want to claim that there was a disagreement over the teachings point to Paul's rebuke of Peter.

"But when Cephas came to Antioch, I opposed him to his face, because he stood condemned. For prior to the coming of certain men from James, he used to eat with the Gentiles; but when they came, he began to withdraw and hold himself aloof, fearing the party of the circumcision. The rest of the Jews joined him in hypocrisy, with the result that even Barnabas was carried away by their hypocrisy. But when I saw that they were not straightforward about the truth of the gospel, I said to Cephas in the presence of all, 'If you, being a Jew, live like the Gentiles and not like the Jews, how is it that you compel the Gentiles to live like Jews?'" (Galatians 2:11-14).

Paul charged Peter and the other brethren with hypocrisy. In other words, Peter was teaching one thing but acting differently in his life. It is Peter who had first taught the Gentiles in Acts 10 and stayed with them for a few days (Acts 10:48), which implies that he ate with them. Peter also argued that they were saved just as the Jews were saved (Acts 11:17). And when false teachers came out of Jerusalem claiming that the Gentiles had to live by the law of Moses, Peter stood against them (Acts 15:7-11). We aren't told how he was pressured into isolating himself from the Gentiles, but Peter never denied that Paul was stating the truth. He failed to live by his own teachings, but his teachings were correct because the Holy Spirit ensured the gospel was taught correctly.

Therefore, there is no record of differences in doctrine between the apostles. Such could not happen with the Holy Spirit delivering the doctrine through the apostles.